--- /dev/null
+# SPDX-License-Identifier: GPL-2.0
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/timer/allwinner,sun4i-a10-timer.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Allwinner A10 Timer Device Tree Bindings
+
+maintainers:
+ - Chen-Yu Tsai <wens@csie.org>
+ - Maxime Ripard <maxime.ripard@bootlin.com>
+
+properties:
+ compatible:
+ enum:
+ - allwinner,sun4i-a10-timer
+ - allwinner,sun8i-a23-timer
+ - allwinner,sun8i-v3s-timer
+ - allwinner,suniv-f1c100s-timer
+
+ reg:
+ maxItems: 1
+
+ interrupts:
+ description:
+ List of timers interrupts
+
+ clocks:
+ maxItems: 1
+
+allOf:
+ - if:
+ properties:
+ compatible:
+ items:
+ const: allwinner,sun4i-a10-timer
+
+ then:
+ properties:
+ interrupts:
+ minItems: 6
+ maxItems: 6
+
+ - if:
+ properties:
+ compatible:
+ items:
+ const: allwinner,sun8i-a23-timer
+
+ then:
+ properties:
+ interrupts:
+ minItems: 2
+ maxItems: 2
+
+ - if:
+ properties:
+ compatible:
+ items:
+ const: allwinner,sun8i-v3s-timer
+
+ then:
+ properties:
+ interrupts:
+ minItems: 3
+ maxItems: 3
+
+ - if:
+ properties:
+ compatible:
+ items:
+ const: allwinner,suniv-f1c100s-timer
+
+ then:
+ properties:
+ interrupts:
+ minItems: 3
+ maxItems: 3
+
+required:
+ - compatible
+ - reg
+ - interrupts
+ - clocks
+
+additionalProperties: false
+
+examples:
+ - |
+ timer {
+ compatible = "allwinner,sun4i-a10-timer";
+ reg = <0x01c20c00 0x400>;
+ interrupts = <22>,
+ <23>,
+ <24>,
+ <25>,
+ <67>,
+ <68>;
+ clocks = <&osc>;
+ };
+
+...
+++ /dev/null
-Allwinner A1X SoCs Timer Controller
-
-Required properties:
-
-- compatible : should be one of the following:
- "allwinner,sun4i-a10-timer"
- "allwinner,suniv-f1c100s-timer"
-- reg : Specifies base physical address and size of the registers.
-- interrupts : The interrupt of the first timer
-- clocks: phandle to the source clock (usually a 24 MHz fixed clock)
-
-Example:
-
-timer {
- compatible = "allwinner,sun4i-a10-timer";
- reg = <0x01c20c00 0x400>;
- interrupts = <22>;
- clocks = <&osc>;
-};
+++ /dev/null
-Allwinner SoCs High Speed Timer Controller
-
-Required properties:
-
-- compatible : should be "allwinner,sun5i-a13-hstimer" or
- "allwinner,sun7i-a20-hstimer"
-- reg : Specifies base physical address and size of the registers.
-- interrupts : The interrupts of these timers (2 for the sun5i IP, 4 for the sun7i
- one)
-- clocks: phandle to the source clock (usually the AHB clock)
-
-Optional properties:
-- resets: phandle to a reset controller asserting the timer
-
-Example:
-
-timer@1c60000 {
- compatible = "allwinner,sun7i-a20-hstimer";
- reg = <0x01c60000 0x1000>;
- interrupts = <0 51 1>,
- <0 52 1>,
- <0 53 1>,
- <0 54 1>;
- clocks = <&ahb1_gates 19>;
- resets = <&ahb1rst 19>;
-};
--- /dev/null
+# SPDX-License-Identifier: GPL-2.0
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/timer/allwinner,sun5i-a13-hstimer.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Allwinner A13 High-Speed Timer Device Tree Bindings
+
+maintainers:
+ - Chen-Yu Tsai <wens@csie.org>
+ - Maxime Ripard <maxime.ripard@bootlin.com>
+
+properties:
+ compatible:
+ oneOf:
+ - const: allwinner,sun5i-a13-hstimer
+ - const: allwinner,sun7i-a20-hstimer
+ - items:
+ - const: allwinner,sun6i-a31-hstimer
+ - const: allwinner,sun7i-a20-hstimer
+
+ reg:
+ maxItems: 1
+
+ interrupts:
+ minItems: 2
+ maxItems: 4
+ items:
+ - description: Timer 0 Interrupt
+ - description: Timer 1 Interrupt
+ - description: Timer 2 Interrupt
+ - description: Timer 3 Interrupt
+
+ clocks:
+ maxItems: 1
+
+ resets:
+ maxItems: 1
+
+required:
+ - compatible
+ - reg
+ - interrupts
+ - clocks
+
+if:
+ properties:
+ compatible:
+ items:
+ const: allwinner,sun5i-a13-hstimer
+
+then:
+ properties:
+ interrupts:
+ minItems: 2
+ maxItems: 2
+
+else:
+ properties:
+ interrupts:
+ minItems: 4
+ maxItems: 4
+
+additionalProperties: false
+
+examples:
+ - |
+ timer@1c60000 {
+ compatible = "allwinner,sun7i-a20-hstimer";
+ reg = <0x01c60000 0x1000>;
+ interrupts = <0 51 1>,
+ <0 52 1>,
+ <0 53 1>,
+ <0 54 1>;
+ clocks = <&ahb1_gates 19>;
+ resets = <&ahb1rst 19>;
+ };
+
+...
Required Properties:
- compatible: must contain one or more of the following:
- - "renesas,cmt-48-sh73a0" for the sh73A0 48-bit CMT
- (CMT1)
- - "renesas,cmt-48-r8a7740" for the r8a7740 48-bit CMT
- (CMT1)
- - "renesas,cmt-48" for all non-second generation 48-bit CMT
- (CMT1 on sh73a0 and r8a7740)
- This is a fallback for the above renesas,cmt-48-* entries.
-
- "renesas,r8a73a4-cmt0" for the 32-bit CMT0 device included in r8a73a4.
- "renesas,r8a73a4-cmt1" for the 48-bit CMT1 device included in r8a73a4.
+ - "renesas,r8a7740-cmt0" for the 32-bit CMT0 device included in r8a7740.
+ - "renesas,r8a7740-cmt1" for the 48-bit CMT1 device included in r8a7740.
+ - "renesas,r8a7740-cmt2" for the 32-bit CMT2 device included in r8a7740.
+ - "renesas,r8a7740-cmt3" for the 32-bit CMT3 device included in r8a7740.
+ - "renesas,r8a7740-cmt4" for the 32-bit CMT4 device included in r8a7740.
- "renesas,r8a7743-cmt0" for the 32-bit CMT0 device included in r8a7743.
- "renesas,r8a7743-cmt1" for the 48-bit CMT1 device included in r8a7743.
- "renesas,r8a7744-cmt0" for the 32-bit CMT0 device included in r8a7744.
- "renesas,r8a77470-cmt0" for the 32-bit CMT0 device included in r8a77470.
- "renesas,r8a77470-cmt1" for the 48-bit CMT1 device included in r8a77470.
- "renesas,r8a774a1-cmt0" for the 32-bit CMT0 device included in r8a774a1.
- - "renesas,r8a774a1-cmt1" for the 48-bit CMT1 device included in r8a774a1.
+ - "renesas,r8a774a1-cmt1" for the 48-bit CMT devices included in r8a774a1.
- "renesas,r8a774c0-cmt0" for the 32-bit CMT0 device included in r8a774c0.
- - "renesas,r8a774c0-cmt1" for the 48-bit CMT1 device included in r8a774c0.
+ - "renesas,r8a774c0-cmt1" for the 48-bit CMT devices included in r8a774c0.
- "renesas,r8a7790-cmt0" for the 32-bit CMT0 device included in r8a7790.
- "renesas,r8a7790-cmt1" for the 48-bit CMT1 device included in r8a7790.
- "renesas,r8a7791-cmt0" for the 32-bit CMT0 device included in r8a7791.
- "renesas,r8a7791-cmt1" for the 48-bit CMT1 device included in r8a7791.
+ - "renesas,r8a7792-cmt0" for the 32-bit CMT0 device included in r8a7792.
+ - "renesas,r8a7792-cmt1" for the 48-bit CMT1 device included in r8a7792.
- "renesas,r8a7793-cmt0" for the 32-bit CMT0 device included in r8a7793.
- "renesas,r8a7793-cmt1" for the 48-bit CMT1 device included in r8a7793.
- "renesas,r8a7794-cmt0" for the 32-bit CMT0 device included in r8a7794.
- "renesas,r8a7794-cmt1" for the 48-bit CMT1 device included in r8a7794.
- "renesas,r8a7795-cmt0" for the 32-bit CMT0 device included in r8a7795.
- - "renesas,r8a7795-cmt1" for the 48-bit CMT1 device included in r8a7795.
+ - "renesas,r8a7795-cmt1" for the 48-bit CMT devices included in r8a7795.
- "renesas,r8a7796-cmt0" for the 32-bit CMT0 device included in r8a7796.
- - "renesas,r8a7796-cmt1" for the 48-bit CMT1 device included in r8a7796.
+ - "renesas,r8a7796-cmt1" for the 48-bit CMT devices included in r8a7796.
- "renesas,r8a77965-cmt0" for the 32-bit CMT0 device included in r8a77965.
- - "renesas,r8a77965-cmt1" for the 48-bit CMT1 device included in r8a77965.
+ - "renesas,r8a77965-cmt1" for the 48-bit CMT devices included in r8a77965.
- "renesas,r8a77970-cmt0" for the 32-bit CMT0 device included in r8a77970.
- - "renesas,r8a77970-cmt1" for the 48-bit CMT1 device included in r8a77970.
+ - "renesas,r8a77970-cmt1" for the 48-bit CMT devices included in r8a77970.
- "renesas,r8a77980-cmt0" for the 32-bit CMT0 device included in r8a77980.
- - "renesas,r8a77980-cmt1" for the 48-bit CMT1 device included in r8a77980.
+ - "renesas,r8a77980-cmt1" for the 48-bit CMT devices included in r8a77980.
- "renesas,r8a77990-cmt0" for the 32-bit CMT0 device included in r8a77990.
- - "renesas,r8a77990-cmt1" for the 48-bit CMT1 device included in r8a77990.
+ - "renesas,r8a77990-cmt1" for the 48-bit CMT devices included in r8a77990.
+ - "renesas,r8a77995-cmt0" for the 32-bit CMT0 device included in r8a77995.
+ - "renesas,r8a77995-cmt1" for the 48-bit CMT devices included in r8a77995.
+ - "renesas,sh73a0-cmt0" for the 32-bit CMT0 device included in sh73a0.
+ - "renesas,sh73a0-cmt1" for the 48-bit CMT1 device included in sh73a0.
+ - "renesas,sh73a0-cmt2" for the 32-bit CMT2 device included in sh73a0.
+ - "renesas,sh73a0-cmt3" for the 32-bit CMT3 device included in sh73a0.
+ - "renesas,sh73a0-cmt4" for the 32-bit CMT4 device included in sh73a0.
- "renesas,rcar-gen2-cmt0" for 32-bit CMT0 devices included in R-Car Gen2
and RZ/G1.
listed above.
- "renesas,rcar-gen3-cmt0" for 32-bit CMT0 devices included in R-Car Gen3
and RZ/G2.
- - "renesas,rcar-gen3-cmt1" for 48-bit CMT1 devices included in R-Car Gen3
+ - "renesas,rcar-gen3-cmt1" for 48-bit CMT devices included in R-Car Gen3
and RZ/G2.
These are fallbacks for R-Car Gen3 and RZ/G2 entries listed
above.
#pwm-cells = <2>;
status = "disabled";
};
+
+ system_counter: timer@306a0000 {
+ compatible = "nxp,sysctr-timer";
+ reg = <0x306a0000 0x20000>;
+ interrupts = <GIC_SPI 47 IRQ_TYPE_LEVEL_HIGH>;
+ clocks = <&osc_24m>;
+ clock-names = "per";
+ };
};
aips3: bus@30800000 {
#pwm-cells = <2>;
status = "disabled";
};
+
+ system_counter: timer@306a0000 {
+ compatible = "nxp,sysctr-timer";
+ reg = <0x306a0000 0x20000>;
+ interrupts = <GIC_SPI 47 IRQ_TYPE_LEVEL_HIGH>;
+ clocks = <&osc_25m>;
+ clock-names = "per";
+ };
};
bus@30800000 { /* AIPS3 */
if (tsc_pg && vclock_was_used(VCLOCK_HVCLOCK))
return vmf_insert_pfn(vma, vmf->address,
- vmalloc_to_pfn(tsc_pg));
+ virt_to_phys(tsc_pg) >> PAGE_SHIFT);
}
return VM_FAULT_SIGBUS;
x86_init.pci.arch_init = hv_pci_init;
- /* Register Hyper-V specific clocksource */
- hv_init_clocksource();
return;
remove_cpuhp_state:
__attribute__((visibility("hidden")));
#endif
-#ifdef CONFIG_HYPERV_TSCPAGE
+#ifdef CONFIG_HYPERV_TIMER
extern struct ms_hyperv_tsc_page hvclock_page
__attribute__((visibility("hidden")));
#endif
}
#endif
-#ifdef CONFIG_HYPERV_TSCPAGE
+#ifdef CONFIG_HYPERV_TIMER
static u64 vread_hvclock(void)
{
return hv_read_tsc_page(&hvclock_page);
return vread_pvclock();
}
#endif
-#ifdef CONFIG_HYPERV_TSCPAGE
+#ifdef CONFIG_HYPERV_TIMER
if (clock_mode == VCLOCK_HVCLOCK) {
barrier();
return vread_hvclock();
#include <asm/timer.h>
#include <asm/reboot.h>
#include <asm/nmi.h>
+#include <clocksource/hyperv_timer.h>
struct ms_hyperv_info ms_hyperv;
EXPORT_SYMBOL_GPL(ms_hyperv);
x2apic_phys = 1;
# endif
+ /* Register Hyper-V specific clocksource */
+ hv_init_clocksource();
+#endif
+}
+
+void hv_setup_sched_clock(void *sched_clock)
+{
+#ifdef CONFIG_PARAVIRT
+ pv_ops.time.sched_clock = sched_clock;
#endif
}
likely(ns > apic->lapic_timer.timer_advance_ns)) {
expire = ktime_add_ns(now, ns);
expire = ktime_sub_ns(expire, ktimer->timer_advance_ns);
- hrtimer_start(&ktimer->timer, expire, HRTIMER_MODE_ABS);
+ hrtimer_start(&ktimer->timer, expire, HRTIMER_MODE_ABS_HARD);
} else
apic_timer_expired(apic);
apic->vcpu = vcpu;
hrtimer_init(&apic->lapic_timer.timer, CLOCK_MONOTONIC,
- HRTIMER_MODE_ABS);
+ HRTIMER_MODE_ABS_HARD);
apic->lapic_timer.timer.function = apic_timer_fn;
if (timer_advance_ns == -1) {
apic->lapic_timer.timer_advance_ns = LAPIC_TIMER_ADVANCE_ADJUST_INIT;
timer = &vcpu->arch.apic->lapic_timer.timer;
if (hrtimer_cancel(timer))
- hrtimer_start_expires(timer, HRTIMER_MODE_ABS);
+ hrtimer_start_expires(timer, HRTIMER_MODE_ABS_HARD);
}
/*
kt = nsecs;
mode = HRTIMER_MODE_REL;
- hrtimer_init_on_stack(&hs.timer, CLOCK_MONOTONIC, mode);
+ hrtimer_init_sleeper_on_stack(&hs, CLOCK_MONOTONIC, mode);
hrtimer_set_expires(&hs.timer, kt);
- hrtimer_init_sleeper(&hs, current);
do {
if (blk_mq_rq_state(rq) == MQ_RQ_COMPLETE)
break;
set_current_state(TASK_UNINTERRUPTIBLE);
- hrtimer_start_expires(&hs.timer, mode);
+ hrtimer_sleeper_start_expires(&hs, mode);
if (hs.task)
io_schedule();
hrtimer_cancel(&hs.timer);
config ATMEL_TCB_CLKSRC
bool "Atmel TC Block timer driver" if COMPILE_TEST
- depends on HAS_IOMEM
+ depends on ARM && HAS_IOMEM
select TIMER_OF if OF
help
Support for Timer Counter Blocks on Atmel SoCs.
platform_set_drvdata(pdev, p);
irq = platform_get_irq(pdev, 0);
- if (irq < 0) {
- dev_err(&pdev->dev, "failed to get irq\n");
+ if (irq < 0)
return irq;
- }
/* map memory, let base point to the STI instance */
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
#include <asm/mshyperv.h>
static struct clock_event_device __percpu *hv_clock_event;
+static u64 hv_sched_clock_offset __ro_after_init;
/*
* If false, we're using the old mechanism for stimer0 interrupts
struct clocksource *hyperv_cs;
EXPORT_SYMBOL_GPL(hyperv_cs);
-#ifdef CONFIG_HYPERV_TSCPAGE
-
-static struct ms_hyperv_tsc_page *tsc_pg;
+static struct ms_hyperv_tsc_page tsc_pg __aligned(PAGE_SIZE);
struct ms_hyperv_tsc_page *hv_get_tsc_page(void)
{
- return tsc_pg;
+ return &tsc_pg;
}
EXPORT_SYMBOL_GPL(hv_get_tsc_page);
-static u64 notrace read_hv_sched_clock_tsc(void)
+static u64 notrace read_hv_clock_tsc(struct clocksource *arg)
{
- u64 current_tick = hv_read_tsc_page(tsc_pg);
+ u64 current_tick = hv_read_tsc_page(&tsc_pg);
if (current_tick == U64_MAX)
hv_get_time_ref_count(current_tick);
return current_tick;
}
-static u64 read_hv_clock_tsc(struct clocksource *arg)
+static u64 read_hv_sched_clock_tsc(void)
{
- return read_hv_sched_clock_tsc();
+ return read_hv_clock_tsc(NULL) - hv_sched_clock_offset;
}
static struct clocksource hyperv_cs_tsc = {
.mask = CLOCKSOURCE_MASK(64),
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
-#endif
-static u64 notrace read_hv_sched_clock_msr(void)
+static u64 notrace read_hv_clock_msr(struct clocksource *arg)
{
u64 current_tick;
/*
return current_tick;
}
-static u64 read_hv_clock_msr(struct clocksource *arg)
+static u64 read_hv_sched_clock_msr(void)
{
- return read_hv_sched_clock_msr();
+ return read_hv_clock_msr(NULL) - hv_sched_clock_offset;
}
static struct clocksource hyperv_cs_msr = {
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
-#ifdef CONFIG_HYPERV_TSCPAGE
static bool __init hv_init_tsc_clocksource(void)
{
u64 tsc_msr;
if (!(ms_hyperv.features & HV_MSR_REFERENCE_TSC_AVAILABLE))
return false;
- tsc_pg = vmalloc(PAGE_SIZE);
- if (!tsc_pg)
- return false;
-
hyperv_cs = &hyperv_cs_tsc;
- phys_addr = page_to_phys(vmalloc_to_page(tsc_pg));
+ phys_addr = virt_to_phys(&tsc_pg);
/*
* The Hyper-V TLFS specifies to preserve the value of reserved
hv_set_clocksource_vdso(hyperv_cs_tsc);
clocksource_register_hz(&hyperv_cs_tsc, NSEC_PER_SEC/100);
- /* sched_clock_register is needed on ARM64 but is a no-op on x86 */
- sched_clock_register(read_hv_sched_clock_tsc, 64, HV_CLOCK_HZ);
+ hv_sched_clock_offset = hyperv_cs->read(hyperv_cs);
+ hv_setup_sched_clock(read_hv_sched_clock_tsc);
+
return true;
}
-#else
-static bool __init hv_init_tsc_clocksource(void)
-{
- return false;
-}
-#endif
-
void __init hv_init_clocksource(void)
{
hyperv_cs = &hyperv_cs_msr;
clocksource_register_hz(&hyperv_cs_msr, NSEC_PER_SEC/100);
- /* sched_clock_register is needed on ARM64 but is a no-op on x86 */
- sched_clock_register(read_hv_sched_clock_msr, 64, HV_CLOCK_HZ);
+ hv_sched_clock_offset = hyperv_cs->read(hyperv_cs);
+ hv_setup_sched_clock(read_hv_sched_clock_msr);
}
EXPORT_SYMBOL_GPL(hv_init_clocksource);
}
rate = clk_get_rate(ostm_clk);
- ostm->ticks_per_jiffy = (rate + HZ / 2) / HZ;
+ ostm->ticks_per_jiffy = DIV_ROUND_CLOSEST(rate, HZ);
/*
* First probed device will be used as system clocksource. Any
int ret;
irq = platform_get_irq(ch->cmt->pdev, ch->index);
- if (irq < 0) {
- dev_err(&ch->cmt->pdev->dev, "ch%u: failed to get irq\n",
- ch->index);
+ if (irq < 0)
return irq;
- }
ret = request_irq(irq, sh_cmt_interrupt,
IRQF_TIMER | IRQF_IRQPOLL | IRQF_NOBALANCING,
MODULE_DEVICE_TABLE(platform, sh_cmt_id_table);
static const struct of_device_id sh_cmt_of_table[] __maybe_unused = {
- { .compatible = "renesas,cmt-48", .data = &sh_cmt_info[SH_CMT_48BIT] },
+ {
+ /* deprecated, preserved for backward compatibility */
+ .compatible = "renesas,cmt-48",
+ .data = &sh_cmt_info[SH_CMT_48BIT]
+ },
{
/* deprecated, preserved for backward compatibility */
.compatible = "renesas,cmt-48-gen2",
.data = &sh_cmt_info[SH_CMT0_RCAR_GEN2]
},
+ {
+ .compatible = "renesas,r8a7740-cmt1",
+ .data = &sh_cmt_info[SH_CMT_48BIT]
+ },
+ {
+ .compatible = "renesas,sh73a0-cmt1",
+ .data = &sh_cmt_info[SH_CMT_48BIT]
+ },
{
.compatible = "renesas,rcar-gen2-cmt0",
.data = &sh_cmt_info[SH_CMT0_RCAR_GEN2]
ch->base = tmu->mapbase + 8 + ch->index * 12;
ch->irq = platform_get_irq(tmu->pdev, index);
- if (ch->irq < 0) {
- dev_err(&tmu->pdev->dev, "ch%u: failed to get irq\n",
- ch->index);
+ if (ch->irq < 0)
return ch->irq;
- }
ch->cs_enabled = false;
ch->enable_count = 0;
#include <linux/irq.h>
#include <linux/clk.h>
+#include <linux/delay.h>
#include <linux/err.h>
#include <linux/ioport.h>
#include <linux/io.h>
return tc_get_cycles32(&clksrc);
}
+static struct delay_timer tc_delay_timer;
+
+static unsigned long tc_delay_timer_read(void)
+{
+ return tc_get_cycles(&clksrc);
+}
+
+static unsigned long notrace tc_delay_timer_read32(void)
+{
+ return tc_get_cycles32(&clksrc);
+}
+
#ifdef CONFIG_GENERIC_CLOCKEVENTS
struct tc_clkevt_device {
/* setup ony channel 0 */
tcb_setup_single_chan(&tc, best_divisor_idx);
tc_sched_clock = tc_sched_clock_read32;
+ tc_delay_timer.read_current_timer = tc_delay_timer_read32;
} else {
/* we have three clocks no matter what the
* underlying platform supports.
/* setup both channel 0 & 1 */
tcb_setup_dual_chan(&tc, best_divisor_idx);
tc_sched_clock = tc_sched_clock_read;
+ tc_delay_timer.read_current_timer = tc_delay_timer_read;
}
/* and away we go! */
sched_clock_register(tc_sched_clock, 32, divided_rate);
+ tc_delay_timer.freq = divided_rate;
+ register_current_timer_delay(&tc_delay_timer);
+
return 0;
err_unregister_clksrc:
#define SYS_CTR_EN 0x1
#define SYS_CTR_IRQ_MASK 0x2
+#define SYS_CTR_CLK_DIV 0x3
+
static void __iomem *sys_ctr_base;
static u32 cmpcr;
if (ret)
return ret;
+ /* system counter clock is divided by 3 internally */
+ to_sysctr.of_clk.rate /= SYS_CTR_CLK_DIV;
+
sys_ctr_base = timer_of_base(&to_sysctr);
cmpcr = readl(sys_ctr_base + CMPCR);
cmpcr &= ~SYS_CTR_EN;
#define NPCM7XX_Tx_INTEN BIT(29)
#define NPCM7XX_Tx_COUNTEN BIT(30)
#define NPCM7XX_Tx_ONESHOT 0x0
-#define NPCM7XX_Tx_OPER GENMASK(27, 3)
+#define NPCM7XX_Tx_OPER GENMASK(28, 27)
#define NPCM7XX_Tx_MIN_PRESCALE 0x1
#define NPCM7XX_Tx_TDR_MASK_BITS 24
#define NPCM7XX_Tx_MAX_CNT 0xFFFFFF
val = readl(timer_of_base(to) + NPCM7XX_REG_TCSR0);
val &= ~NPCM7XX_Tx_OPER;
-
- val = readl(timer_of_base(to) + NPCM7XX_REG_TCSR0);
val |= NPCM7XX_START_ONESHOT_Tx;
writel(val, timer_of_base(to) + NPCM7XX_REG_TCSR0);
struct timer_of *to = to_timer_of(evt);
u32 val;
+ writel(timer_of_period(to), timer_of_base(to) + NPCM7XX_REG_TICR0);
+
val = readl(timer_of_base(to) + NPCM7XX_REG_TCSR0);
val &= ~NPCM7XX_Tx_OPER;
-
- writel(timer_of_period(to), timer_of_base(to) + NPCM7XX_REG_TICR0);
val |= NPCM7XX_START_PERIODIC_Tx;
-
writel(val, timer_of_base(to) + NPCM7XX_REG_TCSR0);
return 0;
of_clk->clk = of_clk->name ? of_clk_get_by_name(np, of_clk->name) :
of_clk_get(np, of_clk->index);
if (IS_ERR(of_clk->clk)) {
- pr_err("Failed to get clock for %pOF\n", np);
- return PTR_ERR(of_clk->clk);
+ ret = PTR_ERR(of_clk->clk);
+ if (ret != -EPROBE_DEFER)
+ pr_err("Failed to get clock for %pOF\n", np);
+ goto out;
}
ret = clk_prepare_enable(of_clk->clk);
ret = init_func_ret(np);
if (ret) {
- pr_err("Failed to initialize '%pOF': %d\n", np, ret);
+ if (ret != -EPROBE_DEFER)
+ pr_err("Failed to initialize '%pOF': %d\n", np,
+ ret);
continue;
}
}
TIMER_OF_DECLARE(sun4i, "allwinner,sun4i-a10-timer",
sun4i_timer_init);
+TIMER_OF_DECLARE(sun8i_a23, "allwinner,sun8i-a23-timer",
+ sun4i_timer_init);
+TIMER_OF_DECLARE(sun8i_v3s, "allwinner,sun8i-v3s-timer",
+ sun4i_timer_init);
TIMER_OF_DECLARE(suniv, "allwinner,suniv-f1c100s-timer",
sun4i_timer_init);
config HYPERV_TIMER
def_bool HYPERV
-config HYPERV_TSCPAGE
- def_bool HYPERV && X86_64
-
config HYPERV_UTILS
tristate "Microsoft Hyper-V Utilities driver"
depends on HYPERV && CONNECTOR && NLS
return -EINVAL;
wake_time = ktime_set(arg->wake_time_sec, arg->wake_time_nsec);
- hrtimer_init_on_stack(&to->timer, CLOCK_MONOTONIC,
- HRTIMER_MODE_ABS);
+ hrtimer_init_sleeper_on_stack(to, CLOCK_MONOTONIC,
+ HRTIMER_MODE_ABS);
hrtimer_set_expires_range_ns(&to->timer, wake_time,
current->timer_slack_ns);
-
- hrtimer_init_sleeper(to, current);
}
while (1) {
break;
}
if (to) {
- hrtimer_start_expires(&to->timer, HRTIMER_MODE_ABS);
+ hrtimer_sleeper_start_expires(to, HRTIMER_MODE_ABS);
if (likely(to->task))
freezable_schedule();
hrtimer_cancel(&to->timer);
break;
}
spin_unlock_irq(&ctx->wqh.lock);
- cpu_relax();
+
+ if (isalarm(ctx))
+ hrtimer_cancel_wait_running(&ctx->t.alarm.timer);
+ else
+ hrtimer_cancel_wait_running(&ctx->t.tmr);
}
/*
void hyperv_report_panic_msg(phys_addr_t pa, size_t size);
bool hv_is_hyperv_initialized(void);
void hyperv_cleanup(void);
+void hv_setup_sched_clock(void *sched_clock);
#else /* CONFIG_HYPERV */
static inline bool hv_is_hyperv_initialized(void) { return false; }
static inline void hyperv_cleanup(void) {}
extern void hv_stimer_global_cleanup(void);
extern void hv_stimer0_isr(void);
-#if IS_ENABLED(CONFIG_HYPERV)
+#ifdef CONFIG_HYPERV_TIMER
extern struct clocksource *hyperv_cs;
extern void hv_init_clocksource(void);
-#endif /* CONFIG_HYPERV */
-#ifdef CONFIG_HYPERV_TSCPAGE
extern struct ms_hyperv_tsc_page *hv_get_tsc_page(void);
static inline notrace u64
return hv_read_tsc_page_tsc(tsc_pg, &cur_tsc);
}
-#else /* CONFIG_HYPERV_TSC_PAGE */
+#else /* CONFIG_HYPERV_TIMER */
static inline struct ms_hyperv_tsc_page *hv_get_tsc_page(void)
{
return NULL;
{
return U64_MAX;
}
-#endif /* CONFIG_HYPERV_TSCPAGE */
+#endif /* CONFIG_HYPERV_TIMER */
#endif
#include <linux/time.h>
#include <linux/hrtimer.h>
#include <linux/timerqueue.h>
-#include <linux/rtc.h>
+
+struct rtc_device;
enum alarmtimer_type {
ALARM_REALTIME,
* when starting the timer)
* HRTIMER_MODE_SOFT - Timer callback function will be executed in
* soft irq context
+ * HRTIMER_MODE_HARD - Timer callback function will be executed in
+ * hard irq context even on PREEMPT_RT.
*/
enum hrtimer_mode {
HRTIMER_MODE_ABS = 0x00,
HRTIMER_MODE_REL = 0x01,
HRTIMER_MODE_PINNED = 0x02,
HRTIMER_MODE_SOFT = 0x04,
+ HRTIMER_MODE_HARD = 0x08,
HRTIMER_MODE_ABS_PINNED = HRTIMER_MODE_ABS | HRTIMER_MODE_PINNED,
HRTIMER_MODE_REL_PINNED = HRTIMER_MODE_REL | HRTIMER_MODE_PINNED,
HRTIMER_MODE_ABS_PINNED_SOFT = HRTIMER_MODE_ABS_PINNED | HRTIMER_MODE_SOFT,
HRTIMER_MODE_REL_PINNED_SOFT = HRTIMER_MODE_REL_PINNED | HRTIMER_MODE_SOFT,
+ HRTIMER_MODE_ABS_HARD = HRTIMER_MODE_ABS | HRTIMER_MODE_HARD,
+ HRTIMER_MODE_REL_HARD = HRTIMER_MODE_REL | HRTIMER_MODE_HARD,
+
+ HRTIMER_MODE_ABS_PINNED_HARD = HRTIMER_MODE_ABS_PINNED | HRTIMER_MODE_HARD,
+ HRTIMER_MODE_REL_PINNED_HARD = HRTIMER_MODE_REL_PINNED | HRTIMER_MODE_HARD,
};
/*
* @state: state information (See bit values above)
* @is_rel: Set if the timer was armed relative
* @is_soft: Set if hrtimer will be expired in soft interrupt context.
+ * @is_hard: Set if hrtimer will be expired in hard interrupt context
+ * even on RT.
*
* The hrtimer structure must be initialized by hrtimer_init()
*/
u8 state;
u8 is_rel;
u8 is_soft;
+ u8 is_hard;
};
/**
* @nr_retries: Total number of hrtimer interrupt retries
* @nr_hangs: Total number of hrtimer interrupt hangs
* @max_hang_time: Maximum time spent in hrtimer_interrupt
+ * @softirq_expiry_lock: Lock which is taken while softirq based hrtimer are
+ * expired
+ * @timer_waiters: A hrtimer_cancel() invocation waits for the timer
+ * callback to finish.
* @expires_next: absolute time of the next event, is required for remote
* hrtimer enqueue; it is the total first expiry time (hard
* and soft hrtimer are taken into account)
unsigned short nr_retries;
unsigned short nr_hangs;
unsigned int max_hang_time;
+#endif
+#ifdef CONFIG_PREEMPT_RT
+ spinlock_t softirq_expiry_lock;
+ atomic_t timer_waiters;
#endif
ktime_t expires_next;
struct hrtimer *next_timer;
DECLARE_PER_CPU(struct tick_device, tick_cpu_device);
+#ifdef CONFIG_PREEMPT_RT
+void hrtimer_cancel_wait_running(const struct hrtimer *timer);
+#else
+static inline void hrtimer_cancel_wait_running(struct hrtimer *timer)
+{
+ cpu_relax();
+}
+#endif
/* Exported timer functions: */
/* Initialize timers: */
extern void hrtimer_init(struct hrtimer *timer, clockid_t which_clock,
enum hrtimer_mode mode);
+extern void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, clockid_t clock_id,
+ enum hrtimer_mode mode);
#ifdef CONFIG_DEBUG_OBJECTS_TIMERS
extern void hrtimer_init_on_stack(struct hrtimer *timer, clockid_t which_clock,
enum hrtimer_mode mode);
+extern void hrtimer_init_sleeper_on_stack(struct hrtimer_sleeper *sl,
+ clockid_t clock_id,
+ enum hrtimer_mode mode);
extern void destroy_hrtimer_on_stack(struct hrtimer *timer);
#else
{
hrtimer_init(timer, which_clock, mode);
}
+
+static inline void hrtimer_init_sleeper_on_stack(struct hrtimer_sleeper *sl,
+ clockid_t clock_id,
+ enum hrtimer_mode mode)
+{
+ hrtimer_init_sleeper(sl, clock_id, mode);
+}
+
static inline void destroy_hrtimer_on_stack(struct hrtimer *timer) { }
#endif
hrtimer_start_range_ns(timer, soft, delta, mode);
}
+void hrtimer_sleeper_start_expires(struct hrtimer_sleeper *sl,
+ enum hrtimer_mode mode);
+
static inline void hrtimer_restart(struct hrtimer *timer)
{
hrtimer_start_expires(timer, HRTIMER_MODE_ABS);
const enum hrtimer_mode mode,
const clockid_t clockid);
-extern void hrtimer_init_sleeper(struct hrtimer_sleeper *sl,
- struct task_struct *tsk);
-
extern int schedule_hrtimeout_range(ktime_t *expires, u64 delta,
- const enum hrtimer_mode mode);
+ const enum hrtimer_mode mode);
extern int schedule_hrtimeout_range_clock(ktime_t *expires,
u64 delta,
const enum hrtimer_mode mode,
#define INIT_PREV_CPUTIME(x)
#endif
-#ifdef CONFIG_POSIX_TIMERS
-#define INIT_CPU_TIMERS(s) \
- .cpu_timers = { \
- LIST_HEAD_INIT(s.cpu_timers[0]), \
- LIST_HEAD_INIT(s.cpu_timers[1]), \
- LIST_HEAD_INIT(s.cpu_timers[2]), \
- },
-#else
-#define INIT_CPU_TIMERS(s)
-#endif
-
#define INIT_TASK_COMM "swapper"
/* Attach to the init_task data structure for proper alignment */
#include <linux/spinlock.h>
#include <linux/list.h>
-#include <linux/sched.h>
-#include <linux/timex.h>
#include <linux/alarmtimer.h>
+#include <linux/timerqueue.h>
-struct siginfo;
-
-struct cpu_timer_list {
- struct list_head entry;
- u64 expires;
- struct task_struct *task;
- int firing;
-};
+struct kernel_siginfo;
+struct task_struct;
/*
* Bit fields within a clockid:
return ~(clk >> 3);
}
+#ifdef CONFIG_POSIX_TIMERS
+
+/**
+ * cpu_timer - Posix CPU timer representation for k_itimer
+ * @node: timerqueue node to queue in the task/sig
+ * @head: timerqueue head on which this timer is queued
+ * @task: Pointer to target task
+ * @elist: List head for the expiry list
+ * @firing: Timer is currently firing
+ */
+struct cpu_timer {
+ struct timerqueue_node node;
+ struct timerqueue_head *head;
+ struct task_struct *task;
+ struct list_head elist;
+ int firing;
+};
+
+static inline bool cpu_timer_enqueue(struct timerqueue_head *head,
+ struct cpu_timer *ctmr)
+{
+ ctmr->head = head;
+ return timerqueue_add(head, &ctmr->node);
+}
+
+static inline void cpu_timer_dequeue(struct cpu_timer *ctmr)
+{
+ if (ctmr->head) {
+ timerqueue_del(ctmr->head, &ctmr->node);
+ ctmr->head = NULL;
+ }
+}
+
+static inline u64 cpu_timer_getexpires(struct cpu_timer *ctmr)
+{
+ return ctmr->node.expires;
+}
+
+static inline void cpu_timer_setexpires(struct cpu_timer *ctmr, u64 exp)
+{
+ ctmr->node.expires = exp;
+}
+
+/**
+ * posix_cputimer_base - Container per posix CPU clock
+ * @nextevt: Earliest-expiration cache
+ * @tqhead: timerqueue head for cpu_timers
+ */
+struct posix_cputimer_base {
+ u64 nextevt;
+ struct timerqueue_head tqhead;
+};
+
+/**
+ * posix_cputimers - Container for posix CPU timer related data
+ * @bases: Base container for posix CPU clocks
+ * @timers_active: Timers are queued.
+ * @expiry_active: Timer expiry is active. Used for
+ * process wide timers to avoid multiple
+ * task trying to handle expiry concurrently
+ *
+ * Used in task_struct and signal_struct
+ */
+struct posix_cputimers {
+ struct posix_cputimer_base bases[CPUCLOCK_MAX];
+ unsigned int timers_active;
+ unsigned int expiry_active;
+};
+
+static inline void posix_cputimers_init(struct posix_cputimers *pct)
+{
+ memset(pct, 0, sizeof(*pct));
+ pct->bases[0].nextevt = U64_MAX;
+ pct->bases[1].nextevt = U64_MAX;
+ pct->bases[2].nextevt = U64_MAX;
+}
+
+void posix_cputimers_group_init(struct posix_cputimers *pct, u64 cpu_limit);
+
+static inline void posix_cputimers_rt_watchdog(struct posix_cputimers *pct,
+ u64 runtime)
+{
+ pct->bases[CPUCLOCK_SCHED].nextevt = runtime;
+}
+
+/* Init task static initializer */
+#define INIT_CPU_TIMERBASE(b) { \
+ .nextevt = U64_MAX, \
+}
+
+#define INIT_CPU_TIMERBASES(b) { \
+ INIT_CPU_TIMERBASE(b[0]), \
+ INIT_CPU_TIMERBASE(b[1]), \
+ INIT_CPU_TIMERBASE(b[2]), \
+}
+
+#define INIT_CPU_TIMERS(s) \
+ .posix_cputimers = { \
+ .bases = INIT_CPU_TIMERBASES(s.posix_cputimers.bases), \
+ },
+#else
+struct posix_cputimers { };
+struct cpu_timer { };
+#define INIT_CPU_TIMERS(s)
+static inline void posix_cputimers_init(struct posix_cputimers *pct) { }
+static inline void posix_cputimers_group_init(struct posix_cputimers *pct,
+ u64 cpu_limit) { }
+#endif
+
#define REQUEUE_PENDING 1
/**
* @it_process: The task to wakeup on clock_nanosleep (CPU timers)
* @sigq: Pointer to preallocated sigqueue
* @it: Union representing the various posix timer type
- * internals. Also used for rcu freeing the timer.
+ * internals.
+ * @rcu: RCU head for freeing the timer.
*/
struct k_itimer {
struct list_head list;
struct {
struct hrtimer timer;
} real;
- struct cpu_timer_list cpu;
+ struct cpu_timer cpu;
struct {
struct alarm alarmtimer;
} alarm;
- struct rcu_head rcu;
} it;
+ struct rcu_head rcu;
};
-void run_posix_cpu_timers(struct task_struct *task);
+void run_posix_cpu_timers(void);
void posix_cpu_timers_exit(struct task_struct *task);
void posix_cpu_timers_exit_group(struct task_struct *task);
void set_process_cpu_timer(struct task_struct *task, unsigned int clock_idx,
#include <linux/resource.h>
#include <linux/latencytop.h>
#include <linux/sched/prio.h>
+#include <linux/sched/types.h>
#include <linux/signal_types.h>
#include <linux/mm_types_task.h>
#include <linux/task_io_accounting.h>
+#include <linux/posix-timers.h>
#include <linux/rseq.h>
/* task_struct member predeclarations (sorted alphabetically): */
#endif
};
-/**
- * struct task_cputime - collected CPU time counts
- * @utime: time spent in user mode, in nanoseconds
- * @stime: time spent in kernel mode, in nanoseconds
- * @sum_exec_runtime: total time spent on the CPU, in nanoseconds
- *
- * This structure groups together three kinds of CPU time that are tracked for
- * threads and thread groups. Most things considering CPU time want to group
- * these counts together and treat all three of them in parallel.
- */
-struct task_cputime {
- u64 utime;
- u64 stime;
- unsigned long long sum_exec_runtime;
-};
-
-/* Alternate field names when used on cache expirations: */
-#define virt_exp utime
-#define prof_exp stime
-#define sched_exp sum_exec_runtime
-
enum vtime_state {
/* Task is sleeping or running in a CPU with VTIME inactive: */
VTIME_INACTIVE = 0,
unsigned long min_flt;
unsigned long maj_flt;
-#ifdef CONFIG_POSIX_TIMERS
- struct task_cputime cputime_expires;
- struct list_head cpu_timers[3];
-#endif
+ /* Empty if CONFIG_POSIX_CPUTIMERS=n */
+ struct posix_cputimers posix_cputimers;
/* Process credentials: */
* Thread group CPU time accounting.
*/
void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times);
-void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times);
-
+void thread_group_sample_cputime(struct task_struct *tsk, u64 *samples);
/*
* The following are functions that support scheduler-internal time accounting.
*/
/**
- * get_running_cputimer - return &tsk->signal->cputimer if cputimer is running
+ * get_running_cputimer - return &tsk->signal->cputimer if cputimers are active
*
* @tsk: Pointer to target task.
*/
{
struct thread_group_cputimer *cputimer = &tsk->signal->cputimer;
- /* Check if cputimer isn't running. This is accessed without locking. */
- if (!READ_ONCE(cputimer->running))
+ /*
+ * Check whether posix CPU timers are active. If not the thread
+ * group accounting is not active either. Lockless check.
+ */
+ if (!READ_ONCE(tsk->signal->posix_cputimers.timers_active))
return NULL;
/*
#include <linux/sched/task.h>
#include <linux/cred.h>
#include <linux/refcount.h>
+#include <linux/posix-timers.h>
/*
* Types defining task->signal and task->sighand and APIs using them:
/**
* struct thread_group_cputimer - thread group interval timer counts
* @cputime_atomic: atomic thread group interval timers.
- * @running: true when there are timers running and
- * @cputime_atomic receives updates.
- * @checking_timer: true when a thread in the group is in the
- * process of checking for thread group timers.
*
* This structure contains the version of task_cputime, above, that is
* used for thread group CPU timer calculations.
*/
struct thread_group_cputimer {
struct task_cputime_atomic cputime_atomic;
- bool running;
- bool checking_timer;
};
struct multiprocess_signals {
*/
struct thread_group_cputimer cputimer;
- /* Earliest-expiration cache. */
- struct task_cputime cputime_expires;
-
- struct list_head cpu_timers[3];
-
#endif
+ /* Empty if CONFIG_POSIX_TIMERS=n */
+ struct posix_cputimers posix_cputimers;
/* PID/PID hash table linkage. */
struct pid *pids[PIDTYPE_MAX];
--- /dev/null
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_SCHED_TYPES_H
+#define _LINUX_SCHED_TYPES_H
+
+#include <linux/types.h>
+
+/**
+ * struct task_cputime - collected CPU time counts
+ * @stime: time spent in kernel mode, in nanoseconds
+ * @utime: time spent in user mode, in nanoseconds
+ * @sum_exec_runtime: total time spent on the CPU, in nanoseconds
+ *
+ * This structure groups together three kinds of CPU time that are tracked for
+ * threads and thread groups. Most things considering CPU time want to group
+ * these counts together and treat all three of them in parallel.
+ */
+struct task_cputime {
+ u64 stime;
+ u64 utime;
+ unsigned long long sum_exec_runtime;
+};
+
+#endif
extern int try_to_del_timer_sync(struct timer_list *timer);
-#ifdef CONFIG_SMP
+#if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT_RT)
extern int del_timer_sync(struct timer_list *timer);
#else
# define del_timer_sync(t) del_timer(t)
};
struct timerqueue_head {
- struct rb_root head;
- struct timerqueue_node *next;
+ struct rb_root_cached rb_root;
};
*
* @head: head of timerqueue
*
- * Returns a pointer to the timer node that has the
- * earliest expiration time.
+ * Returns a pointer to the timer node that has the earliest expiration time.
*/
static inline
struct timerqueue_node *timerqueue_getnext(struct timerqueue_head *head)
{
- return head->next;
+ struct rb_node *leftmost = rb_first_cached(&head->rb_root);
+
+ return rb_entry(leftmost, struct timerqueue_node, node);
}
static inline void timerqueue_init(struct timerqueue_node *node)
RB_CLEAR_NODE(&node->node);
}
+static inline bool timerqueue_node_queued(struct timerqueue_node *node)
+{
+ return !RB_EMPTY_NODE(&node->node);
+}
+
+static inline bool timerqueue_node_expires(struct timerqueue_node *node)
+{
+ return node->expires;
+}
+
static inline void timerqueue_init_head(struct timerqueue_head *head)
{
- head->head = RB_ROOT;
- head->next = NULL;
+ head->rb_root = RB_ROOT_CACHED;
}
#endif /* _LINUX_TIMERQUEUE_H */
int __ret = 0; \
struct hrtimer_sleeper __t; \
\
- hrtimer_init_on_stack(&__t.timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); \
- hrtimer_init_sleeper(&__t, current); \
+ hrtimer_init_sleeper_on_stack(&__t, CLOCK_MONOTONIC, \
+ HRTIMER_MODE_REL); \
if ((timeout) != KTIME_MAX) \
hrtimer_start_range_ns(&__t.timer, timeout, \
current->timer_slack_ns, \
.posix_timers = LIST_HEAD_INIT(init_signals.posix_timers),
.cputimer = {
.cputime_atomic = INIT_CPUTIME_ATOMIC,
- .running = false,
- .checking_timer = false,
},
#endif
INIT_CPU_TIMERS(init_signals)
cpuctx->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * interval);
raw_spin_lock_init(&cpuctx->hrtimer_lock);
- hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED);
+ hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED_HARD);
timer->function = perf_mux_hrtimer_handler;
}
if (!cpuctx->hrtimer_active) {
cpuctx->hrtimer_active = 1;
hrtimer_forward_now(timer, cpuctx->hrtimer_interval);
- hrtimer_start_expires(timer, HRTIMER_MODE_ABS_PINNED);
+ hrtimer_start_expires(timer, HRTIMER_MODE_ABS_PINNED_HARD);
}
raw_spin_unlock_irqrestore(&cpuctx->hrtimer_lock, flags);
period = max_t(u64, 10000, hwc->sample_period);
}
hrtimer_start(&hwc->hrtimer, ns_to_ktime(period),
- HRTIMER_MODE_REL_PINNED);
+ HRTIMER_MODE_REL_PINNED_HARD);
}
static void perf_swevent_cancel_hrtimer(struct perf_event *event)
if (!is_sampling_event(event))
return;
- hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+ hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD);
hwc->hrtimer.function = perf_swevent_hrtimer;
/*
}
}
-#ifdef CONFIG_POSIX_TIMERS
/*
* Initialize POSIX timer handling for a thread group.
*/
static void posix_cpu_timers_init_group(struct signal_struct *sig)
{
+ struct posix_cputimers *pct = &sig->posix_cputimers;
unsigned long cpu_limit;
cpu_limit = READ_ONCE(sig->rlim[RLIMIT_CPU].rlim_cur);
- if (cpu_limit != RLIM_INFINITY) {
- sig->cputime_expires.prof_exp = cpu_limit * NSEC_PER_SEC;
- sig->cputimer.running = true;
- }
-
- /* The timer lists. */
- INIT_LIST_HEAD(&sig->cpu_timers[0]);
- INIT_LIST_HEAD(&sig->cpu_timers[1]);
- INIT_LIST_HEAD(&sig->cpu_timers[2]);
+ posix_cputimers_group_init(pct, cpu_limit);
}
-#else
-static inline void posix_cpu_timers_init_group(struct signal_struct *sig) { }
-#endif
static int copy_signal(unsigned long clone_flags, struct task_struct *tsk)
{
#endif
}
-#ifdef CONFIG_POSIX_TIMERS
-/*
- * Initialize POSIX timer handling for a single task.
- */
-static void posix_cpu_timers_init(struct task_struct *tsk)
-{
- tsk->cputime_expires.prof_exp = 0;
- tsk->cputime_expires.virt_exp = 0;
- tsk->cputime_expires.sched_exp = 0;
- INIT_LIST_HEAD(&tsk->cpu_timers[0]);
- INIT_LIST_HEAD(&tsk->cpu_timers[1]);
- INIT_LIST_HEAD(&tsk->cpu_timers[2]);
-}
-#else
-static inline void posix_cpu_timers_init(struct task_struct *tsk) { }
-#endif
-
static inline void init_task_pid_links(struct task_struct *task)
{
enum pid_type type;
task_io_accounting_init(&p->ioac);
acct_clear_integrals(p);
- posix_cpu_timers_init(p);
+ posix_cputimers_init(&p->posix_cputimers);
p->io_context = NULL;
audit_set_context(p, NULL);
if (!time)
return NULL;
- hrtimer_init_on_stack(&timeout->timer, (flags & FLAGS_CLOCKRT) ?
- CLOCK_REALTIME : CLOCK_MONOTONIC,
- HRTIMER_MODE_ABS);
- hrtimer_init_sleeper(timeout, current);
-
+ hrtimer_init_sleeper_on_stack(timeout, (flags & FLAGS_CLOCKRT) ?
+ CLOCK_REALTIME : CLOCK_MONOTONIC,
+ HRTIMER_MODE_ABS);
/*
* If range_ns is 0, calling hrtimer_set_expires_range_ns() is
* effectively the same as calling hrtimer_set_expires().
/* Arm the timer */
if (timeout)
- hrtimer_start_expires(&timeout->timer, HRTIMER_MODE_ABS);
+ hrtimer_sleeper_start_expires(timeout, HRTIMER_MODE_ABS);
/*
* If we have been removed from the hash list, then another task
}
if (unlikely(to))
- hrtimer_start_expires(&to->timer, HRTIMER_MODE_ABS);
+ hrtimer_sleeper_start_expires(to, HRTIMER_MODE_ABS);
ret = rt_mutex_wait_proxy_lock(&q.pi_state->pi_mutex, to, &rt_waiter);
{
struct hrtimer *timer = &rq->hrtick_timer;
- hrtimer_start_expires(timer, HRTIMER_MODE_ABS_PINNED);
+ hrtimer_start_expires(timer, HRTIMER_MODE_ABS_PINNED_HARD);
}
/*
*/
delay = max_t(u64, delay, 10000LL);
hrtimer_start(&rq->hrtick_timer, ns_to_ktime(delay),
- HRTIMER_MODE_REL_PINNED);
+ HRTIMER_MODE_REL_PINNED_HARD);
}
#endif /* CONFIG_SMP */
rq->hrtick_csd.info = rq;
#endif
- hrtimer_init(&rq->hrtick_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+ hrtimer_init(&rq->hrtick_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD);
rq->hrtick_timer.function = hrtick;
}
#else /* CONFIG_SCHED_HRTICK */
dl_se->dl_non_contending = 1;
get_task_struct(p);
- hrtimer_start(timer, ns_to_ktime(zerolag_time), HRTIMER_MODE_REL);
+ hrtimer_start(timer, ns_to_ktime(zerolag_time), HRTIMER_MODE_REL_HARD);
}
static void task_contending(struct sched_dl_entity *dl_se, int flags)
*/
if (!hrtimer_is_queued(timer)) {
get_task_struct(p);
- hrtimer_start(timer, act, HRTIMER_MODE_ABS);
+ hrtimer_start(timer, act, HRTIMER_MODE_ABS_HARD);
}
return 1;
{
struct hrtimer *timer = &dl_se->dl_timer;
- hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+ hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD);
timer->function = dl_task_timer;
}
{
struct hrtimer *timer = &dl_se->inactive_timer;
- hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+ hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD);
timer->function = inactive_task_timer;
}
raw_spin_lock_init(&rt_b->rt_runtime_lock);
- hrtimer_init(&rt_b->rt_period_timer,
- CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+ hrtimer_init(&rt_b->rt_period_timer, CLOCK_MONOTONIC,
+ HRTIMER_MODE_REL_HARD);
rt_b->rt_period_timer.function = sched_rt_period_timer;
}
* to update the period.
*/
hrtimer_forward_now(&rt_b->rt_period_timer, ns_to_ktime(0));
- hrtimer_start_expires(&rt_b->rt_period_timer, HRTIMER_MODE_ABS_PINNED);
+ hrtimer_start_expires(&rt_b->rt_period_timer,
+ HRTIMER_MODE_ABS_PINNED_HARD);
}
raw_spin_unlock(&rt_b->rt_runtime_lock);
}
}
next = DIV_ROUND_UP(min(soft, hard), USEC_PER_SEC/HZ);
- if (p->rt.timeout > next)
- p->cputime_expires.sched_exp = p->se.sum_exec_runtime;
+ if (p->rt.timeout > next) {
+ posix_cputimers_rt_watchdog(&p->posix_cputimers,
+ p->se.sum_exec_runtime);
+ }
}
}
#else
retval = -EPERM;
if (!retval)
retval = security_task_setrlimit(tsk, resource, new_rlim);
- if (resource == RLIMIT_CPU && new_rlim->rlim_cur == 0) {
- /*
- * The caller is asking for an immediate RLIMIT_CPU
- * expiry. But we use the zero value to mean "it was
- * never set". So let's cheat and make it one second
- * instead
- */
- new_rlim->rlim_cur = 1;
- }
}
if (!retval) {
if (old_rlim)
task_unlock(tsk->group_leader);
/*
- * RLIMIT_CPU handling. Note that the kernel fails to return an error
- * code if it rejected the user's attempt to set RLIMIT_CPU. This is a
- * very long-standing error, and fixing it now risks breakage of
- * applications, so we live with it
+ * RLIMIT_CPU handling. Arm the posix CPU timer if the limit is not
+ * infite. In case of RLIM_INFINITY the posix CPU timer code
+ * ignores the rlimit.
*/
if (!retval && new_rlim && resource == RLIMIT_CPU &&
new_rlim->rlim_cur != RLIM_INFINITY &&
int ret = alarm_try_to_cancel(alarm);
if (ret >= 0)
return ret;
- cpu_relax();
+ hrtimer_cancel_wait_running(&alarm->timer);
}
}
EXPORT_SYMBOL_GPL(alarm_cancel);
return alarm_try_to_cancel(&timr->it.alarm.alarmtimer);
}
+/**
+ * alarm_timer_wait_running - Posix timer callback to wait for a timer
+ * @timr: Pointer to the posixtimer data struct
+ *
+ * Called from the core code when timer cancel detected that the callback
+ * is running. @timr is unlocked and rcu read lock is held to prevent it
+ * from being freed.
+ */
+static void alarm_timer_wait_running(struct k_itimer *timr)
+{
+ hrtimer_cancel_wait_running(&timr->it.alarm.alarmtimer.timer);
+}
+
/**
* alarm_timer_arm - Posix timer callback to arm a timer
* @timr: Pointer to the posixtimer data struct
.timer_forward = alarm_timer_forward,
.timer_remaining = alarm_timer_remaining,
.timer_try_to_cancel = alarm_timer_try_to_cancel,
+ .timer_wait_running = alarm_timer_wait_running,
.nsleep = alarm_timer_nsleep,
};
#endif /* CONFIG_POSIX_TIMERS */
#define migration_base migration_cpu_base.clock_base[0]
+static inline bool is_migration_base(struct hrtimer_clock_base *base)
+{
+ return base == &migration_base;
+}
+
/*
* We are using hashed locking: holding per_cpu(hrtimer_bases)[n].lock
* means that all timers which are tied to this base via timer->base are
#else /* CONFIG_SMP */
+static inline bool is_migration_base(struct hrtimer_clock_base *base)
+{
+ return false;
+}
+
static inline struct hrtimer_clock_base *
lock_hrtimer_base(const struct hrtimer *timer, unsigned long *flags)
{
}
EXPORT_SYMBOL_GPL(hrtimer_init_on_stack);
+static void __hrtimer_init_sleeper(struct hrtimer_sleeper *sl,
+ clockid_t clock_id, enum hrtimer_mode mode);
+
+void hrtimer_init_sleeper_on_stack(struct hrtimer_sleeper *sl,
+ clockid_t clock_id, enum hrtimer_mode mode)
+{
+ debug_object_init_on_stack(&sl->timer, &hrtimer_debug_descr);
+ __hrtimer_init_sleeper(sl, clock_id, mode);
+}
+EXPORT_SYMBOL_GPL(hrtimer_init_sleeper_on_stack);
+
void destroy_hrtimer_on_stack(struct hrtimer *timer)
{
debug_object_free(timer, &hrtimer_debug_descr);
/*
* Check whether the HRTIMER_MODE_SOFT bit and hrtimer.is_soft
- * match.
+ * match on CONFIG_PREEMPT_RT = n. With PREEMPT_RT check the hard
+ * expiry mode because unmarked timers are moved to softirq expiry.
*/
- WARN_ON_ONCE(!(mode & HRTIMER_MODE_SOFT) ^ !timer->is_soft);
+ if (!IS_ENABLED(CONFIG_PREEMPT_RT))
+ WARN_ON_ONCE(!(mode & HRTIMER_MODE_SOFT) ^ !timer->is_soft);
+ else
+ WARN_ON_ONCE(!(mode & HRTIMER_MODE_HARD) ^ !timer->is_hard);
base = lock_hrtimer_base(timer, &flags);
}
EXPORT_SYMBOL_GPL(hrtimer_try_to_cancel);
+#ifdef CONFIG_PREEMPT_RT
+static void hrtimer_cpu_base_init_expiry_lock(struct hrtimer_cpu_base *base)
+{
+ spin_lock_init(&base->softirq_expiry_lock);
+}
+
+static void hrtimer_cpu_base_lock_expiry(struct hrtimer_cpu_base *base)
+{
+ spin_lock(&base->softirq_expiry_lock);
+}
+
+static void hrtimer_cpu_base_unlock_expiry(struct hrtimer_cpu_base *base)
+{
+ spin_unlock(&base->softirq_expiry_lock);
+}
+
+/*
+ * The counterpart to hrtimer_cancel_wait_running().
+ *
+ * If there is a waiter for cpu_base->expiry_lock, then it was waiting for
+ * the timer callback to finish. Drop expiry_lock and reaquire it. That
+ * allows the waiter to acquire the lock and make progress.
+ */
+static void hrtimer_sync_wait_running(struct hrtimer_cpu_base *cpu_base,
+ unsigned long flags)
+{
+ if (atomic_read(&cpu_base->timer_waiters)) {
+ raw_spin_unlock_irqrestore(&cpu_base->lock, flags);
+ spin_unlock(&cpu_base->softirq_expiry_lock);
+ spin_lock(&cpu_base->softirq_expiry_lock);
+ raw_spin_lock_irq(&cpu_base->lock);
+ }
+}
+
+/*
+ * This function is called on PREEMPT_RT kernels when the fast path
+ * deletion of a timer failed because the timer callback function was
+ * running.
+ *
+ * This prevents priority inversion: if the soft irq thread is preempted
+ * in the middle of a timer callback, then calling del_timer_sync() can
+ * lead to two issues:
+ *
+ * - If the caller is on a remote CPU then it has to spin wait for the timer
+ * handler to complete. This can result in unbound priority inversion.
+ *
+ * - If the caller originates from the task which preempted the timer
+ * handler on the same CPU, then spin waiting for the timer handler to
+ * complete is never going to end.
+ */
+void hrtimer_cancel_wait_running(const struct hrtimer *timer)
+{
+ /* Lockless read. Prevent the compiler from reloading it below */
+ struct hrtimer_clock_base *base = READ_ONCE(timer->base);
+
+ /*
+ * Just relax if the timer expires in hard interrupt context or if
+ * it is currently on the migration base.
+ */
+ if (!timer->is_soft || is_migration_base(base)) {
+ cpu_relax();
+ return;
+ }
+
+ /*
+ * Mark the base as contended and grab the expiry lock, which is
+ * held by the softirq across the timer callback. Drop the lock
+ * immediately so the softirq can expire the next timer. In theory
+ * the timer could already be running again, but that's more than
+ * unlikely and just causes another wait loop.
+ */
+ atomic_inc(&base->cpu_base->timer_waiters);
+ spin_lock_bh(&base->cpu_base->softirq_expiry_lock);
+ atomic_dec(&base->cpu_base->timer_waiters);
+ spin_unlock_bh(&base->cpu_base->softirq_expiry_lock);
+}
+#else
+static inline void
+hrtimer_cpu_base_init_expiry_lock(struct hrtimer_cpu_base *base) { }
+static inline void
+hrtimer_cpu_base_lock_expiry(struct hrtimer_cpu_base *base) { }
+static inline void
+hrtimer_cpu_base_unlock_expiry(struct hrtimer_cpu_base *base) { }
+static inline void hrtimer_sync_wait_running(struct hrtimer_cpu_base *base,
+ unsigned long flags) { }
+#endif
+
/**
* hrtimer_cancel - cancel a timer and wait for the handler to finish.
* @timer: the timer to be cancelled
*/
int hrtimer_cancel(struct hrtimer *timer)
{
- for (;;) {
- int ret = hrtimer_try_to_cancel(timer);
+ int ret;
- if (ret >= 0)
- return ret;
- cpu_relax();
- }
+ do {
+ ret = hrtimer_try_to_cancel(timer);
+
+ if (ret < 0)
+ hrtimer_cancel_wait_running(timer);
+ } while (ret < 0);
+ return ret;
}
EXPORT_SYMBOL_GPL(hrtimer_cancel);
enum hrtimer_mode mode)
{
bool softtimer = !!(mode & HRTIMER_MODE_SOFT);
- int base = softtimer ? HRTIMER_MAX_CLOCK_BASES / 2 : 0;
struct hrtimer_cpu_base *cpu_base;
+ int base;
+
+ /*
+ * On PREEMPT_RT enabled kernels hrtimers which are not explicitely
+ * marked for hard interrupt expiry mode are moved into soft
+ * interrupt context for latency reasons and because the callbacks
+ * can invoke functions which might sleep on RT, e.g. spin_lock().
+ */
+ if (IS_ENABLED(CONFIG_PREEMPT_RT) && !(mode & HRTIMER_MODE_HARD))
+ softtimer = true;
memset(timer, 0, sizeof(struct hrtimer));
if (clock_id == CLOCK_REALTIME && mode & HRTIMER_MODE_REL)
clock_id = CLOCK_MONOTONIC;
+ base = softtimer ? HRTIMER_MAX_CLOCK_BASES / 2 : 0;
base += hrtimer_clockid_to_base(clock_id);
timer->is_soft = softtimer;
+ timer->is_hard = !softtimer;
timer->base = &cpu_base->clock_base[base];
timerqueue_init(&timer->node);
}
break;
__run_hrtimer(cpu_base, base, timer, &basenow, flags);
+ if (active_mask == HRTIMER_ACTIVE_SOFT)
+ hrtimer_sync_wait_running(cpu_base, flags);
}
}
}
unsigned long flags;
ktime_t now;
+ hrtimer_cpu_base_lock_expiry(cpu_base);
raw_spin_lock_irqsave(&cpu_base->lock, flags);
now = hrtimer_update_base(cpu_base);
hrtimer_update_softirq_timer(cpu_base, true);
raw_spin_unlock_irqrestore(&cpu_base->lock, flags);
+ hrtimer_cpu_base_unlock_expiry(cpu_base);
}
#ifdef CONFIG_HIGH_RES_TIMERS
return HRTIMER_NORESTART;
}
-void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, struct task_struct *task)
+/**
+ * hrtimer_sleeper_start_expires - Start a hrtimer sleeper timer
+ * @sl: sleeper to be started
+ * @mode: timer mode abs/rel
+ *
+ * Wrapper around hrtimer_start_expires() for hrtimer_sleeper based timers
+ * to allow PREEMPT_RT to tweak the delivery mode (soft/hardirq context)
+ */
+void hrtimer_sleeper_start_expires(struct hrtimer_sleeper *sl,
+ enum hrtimer_mode mode)
+{
+ /*
+ * Make the enqueue delivery mode check work on RT. If the sleeper
+ * was initialized for hard interrupt delivery, force the mode bit.
+ * This is a special case for hrtimer_sleepers because
+ * hrtimer_init_sleeper() determines the delivery mode on RT so the
+ * fiddling with this decision is avoided at the call sites.
+ */
+ if (IS_ENABLED(CONFIG_PREEMPT_RT) && sl->timer.is_hard)
+ mode |= HRTIMER_MODE_HARD;
+
+ hrtimer_start_expires(&sl->timer, mode);
+}
+EXPORT_SYMBOL_GPL(hrtimer_sleeper_start_expires);
+
+static void __hrtimer_init_sleeper(struct hrtimer_sleeper *sl,
+ clockid_t clock_id, enum hrtimer_mode mode)
{
+ /*
+ * On PREEMPT_RT enabled kernels hrtimers which are not explicitely
+ * marked for hard interrupt expiry mode are moved into soft
+ * interrupt context either for latency reasons or because the
+ * hrtimer callback takes regular spinlocks or invokes other
+ * functions which are not suitable for hard interrupt context on
+ * PREEMPT_RT.
+ *
+ * The hrtimer_sleeper callback is RT compatible in hard interrupt
+ * context, but there is a latency concern: Untrusted userspace can
+ * spawn many threads which arm timers for the same expiry time on
+ * the same CPU. That causes a latency spike due to the wakeup of
+ * a gazillion threads.
+ *
+ * OTOH, priviledged real-time user space applications rely on the
+ * low latency of hard interrupt wakeups. If the current task is in
+ * a real-time scheduling class, mark the mode for hard interrupt
+ * expiry.
+ */
+ if (IS_ENABLED(CONFIG_PREEMPT_RT)) {
+ if (task_is_realtime(current) && !(mode & HRTIMER_MODE_SOFT))
+ mode |= HRTIMER_MODE_HARD;
+ }
+
+ __hrtimer_init(&sl->timer, clock_id, mode);
sl->timer.function = hrtimer_wakeup;
- sl->task = task;
+ sl->task = current;
+}
+
+/**
+ * hrtimer_init_sleeper - initialize sleeper to the given clock
+ * @sl: sleeper to be initialized
+ * @clock_id: the clock to be used
+ * @mode: timer mode abs/rel
+ */
+void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, clockid_t clock_id,
+ enum hrtimer_mode mode)
+{
+ debug_init(&sl->timer, clock_id, mode);
+ __hrtimer_init_sleeper(sl, clock_id, mode);
+
}
EXPORT_SYMBOL_GPL(hrtimer_init_sleeper);
{
struct restart_block *restart;
- hrtimer_init_sleeper(t, current);
-
do {
set_current_state(TASK_INTERRUPTIBLE);
- hrtimer_start_expires(&t->timer, mode);
+ hrtimer_sleeper_start_expires(t, mode);
if (likely(t->task))
freezable_schedule();
struct hrtimer_sleeper t;
int ret;
- hrtimer_init_on_stack(&t.timer, restart->nanosleep.clockid,
- HRTIMER_MODE_ABS);
+ hrtimer_init_sleeper_on_stack(&t, restart->nanosleep.clockid,
+ HRTIMER_MODE_ABS);
hrtimer_set_expires_tv64(&t.timer, restart->nanosleep.expires);
-
ret = do_nanosleep(&t, HRTIMER_MODE_ABS);
destroy_hrtimer_on_stack(&t.timer);
return ret;
if (dl_task(current) || rt_task(current))
slack = 0;
- hrtimer_init_on_stack(&t.timer, clockid, mode);
+ hrtimer_init_sleeper_on_stack(&t, clockid, mode);
hrtimer_set_expires_range_ns(&t.timer, timespec64_to_ktime(*rqtp), slack);
ret = do_nanosleep(&t, mode);
if (ret != -ERESTART_RESTARTBLOCK)
cpu_base->softirq_next_timer = NULL;
cpu_base->expires_next = KTIME_MAX;
cpu_base->softirq_expires_next = KTIME_MAX;
+ hrtimer_cpu_base_init_expiry_lock(cpu_base);
return 0;
}
return -EINTR;
}
- hrtimer_init_on_stack(&t.timer, clock_id, mode);
+ hrtimer_init_sleeper_on_stack(&t, clock_id, mode);
hrtimer_set_expires_range_ns(&t.timer, *expires, delta);
-
- hrtimer_init_sleeper(&t, current);
-
- hrtimer_start_expires(&t.timer, mode);
+ hrtimer_sleeper_start_expires(&t, mode);
if (likely(t.task))
schedule();
val = it->expires;
interval = it->incr;
if (val) {
- struct task_cputime cputime;
- u64 t;
+ u64 t, samples[CPUCLOCK_MAX];
- thread_group_cputimer(tsk, &cputime);
- if (clock_id == CPUCLOCK_PROF)
- t = cputime.utime + cputime.stime;
- else
- /* CPUCLOCK_VIRT */
- t = cputime.utime;
+ thread_group_sample_cputime(tsk, samples);
+ t = samples[clock_id];
if (val < t)
/* about to fire */
/* We are sharing ->siglock with it_real_fn() */
if (hrtimer_try_to_cancel(timer) < 0) {
spin_unlock_irq(&tsk->sighand->siglock);
+ hrtimer_cancel_wait_running(timer);
goto again;
}
expires = timeval_to_ktime(value->it_value);
static void posix_cpu_timer_rearm(struct k_itimer *timer);
+void posix_cputimers_group_init(struct posix_cputimers *pct, u64 cpu_limit)
+{
+ posix_cputimers_init(pct);
+ if (cpu_limit != RLIM_INFINITY) {
+ pct->bases[CPUCLOCK_PROF].nextevt = cpu_limit * NSEC_PER_SEC;
+ pct->timers_active = true;
+ }
+}
+
/*
* Called after updating RLIMIT_CPU to run cpu timer and update
- * tsk->signal->cputime_expires expiration cache if necessary. Needs
- * siglock protection since other code may update expiration cache as
- * well.
+ * tsk->signal->posix_cputimers.bases[clock].nextevt expiration cache if
+ * necessary. Needs siglock protection since other code may update the
+ * expiration cache as well.
*/
void update_rlimit_cpu(struct task_struct *task, unsigned long rlim_new)
{
spin_unlock_irq(&task->sighand->siglock);
}
-static int check_clock(const clockid_t which_clock)
+/*
+ * Functions for validating access to tasks.
+ */
+static struct task_struct *lookup_task(const pid_t pid, bool thread,
+ bool gettime)
{
- int error = 0;
struct task_struct *p;
- const pid_t pid = CPUCLOCK_PID(which_clock);
-
- if (CPUCLOCK_WHICH(which_clock) >= CPUCLOCK_MAX)
- return -EINVAL;
- if (pid == 0)
- return 0;
+ /*
+ * If the encoded PID is 0, then the timer is targeted at current
+ * or the process to which current belongs.
+ */
+ if (!pid)
+ return thread ? current : current->group_leader;
- rcu_read_lock();
p = find_task_by_vpid(pid);
- if (!p || !(CPUCLOCK_PERTHREAD(which_clock) ?
- same_thread_group(p, current) : has_group_leader_pid(p))) {
- error = -EINVAL;
+ if (!p)
+ return p;
+
+ if (thread)
+ return same_thread_group(p, current) ? p : NULL;
+
+ if (gettime) {
+ /*
+ * For clock_gettime(PROCESS) the task does not need to be
+ * the actual group leader. tsk->sighand gives
+ * access to the group's clock.
+ *
+ * Timers need the group leader because they take a
+ * reference on it and store the task pointer until the
+ * timer is destroyed.
+ */
+ return (p == current || thread_group_leader(p)) ? p : NULL;
}
+
+ /*
+ * For processes require that p is group leader.
+ */
+ return has_group_leader_pid(p) ? p : NULL;
+}
+
+static struct task_struct *__get_task_for_clock(const clockid_t clock,
+ bool getref, bool gettime)
+{
+ const bool thread = !!CPUCLOCK_PERTHREAD(clock);
+ const pid_t pid = CPUCLOCK_PID(clock);
+ struct task_struct *p;
+
+ if (CPUCLOCK_WHICH(clock) >= CPUCLOCK_MAX)
+ return NULL;
+
+ rcu_read_lock();
+ p = lookup_task(pid, thread, gettime);
+ if (p && getref)
+ get_task_struct(p);
rcu_read_unlock();
+ return p;
+}
- return error;
+static inline struct task_struct *get_task_for_clock(const clockid_t clock)
+{
+ return __get_task_for_clock(clock, true, false);
+}
+
+static inline struct task_struct *get_task_for_clock_get(const clockid_t clock)
+{
+ return __get_task_for_clock(clock, true, true);
+}
+
+static inline int validate_clock_permissions(const clockid_t clock)
+{
+ return __get_task_for_clock(clock, false, false) ? 0 : -EINVAL;
}
/*
* Update expiry time from increment, and increase overrun count,
* given the current clock sample.
*/
-static void bump_cpu_timer(struct k_itimer *timer, u64 now)
+static u64 bump_cpu_timer(struct k_itimer *timer, u64 now)
{
+ u64 delta, incr, expires = timer->it.cpu.node.expires;
int i;
- u64 delta, incr;
if (!timer->it_interval)
- return;
+ return expires;
- if (now < timer->it.cpu.expires)
- return;
+ if (now < expires)
+ return expires;
incr = timer->it_interval;
- delta = now + incr - timer->it.cpu.expires;
+ delta = now + incr - expires;
/* Don't use (incr*2 < delta), incr*2 might overflow. */
for (i = 0; incr < delta - incr; i++)
if (delta < incr)
continue;
- timer->it.cpu.expires += incr;
+ timer->it.cpu.node.expires += incr;
timer->it_overrun += 1LL << i;
delta -= incr;
}
+ return timer->it.cpu.node.expires;
}
-/**
- * task_cputime_zero - Check a task_cputime struct for all zero fields.
- *
- * @cputime: The struct to compare.
- *
- * Checks @cputime to see if all fields are zero. Returns true if all fields
- * are zero, false if any field is nonzero.
- */
-static inline int task_cputime_zero(const struct task_cputime *cputime)
+/* Check whether all cache entries contain U64_MAX, i.e. eternal expiry time */
+static inline bool expiry_cache_is_inactive(const struct posix_cputimers *pct)
{
- if (!cputime->utime && !cputime->stime && !cputime->sum_exec_runtime)
- return 1;
- return 0;
-}
-
-static inline u64 prof_ticks(struct task_struct *p)
-{
- u64 utime, stime;
-
- task_cputime(p, &utime, &stime);
-
- return utime + stime;
-}
-static inline u64 virt_ticks(struct task_struct *p)
-{
- u64 utime, stime;
-
- task_cputime(p, &utime, &stime);
-
- return utime;
+ return !(~pct->bases[CPUCLOCK_PROF].nextevt |
+ ~pct->bases[CPUCLOCK_VIRT].nextevt |
+ ~pct->bases[CPUCLOCK_SCHED].nextevt);
}
static int
posix_cpu_clock_getres(const clockid_t which_clock, struct timespec64 *tp)
{
- int error = check_clock(which_clock);
+ int error = validate_clock_permissions(which_clock);
+
if (!error) {
tp->tv_sec = 0;
tp->tv_nsec = ((NSEC_PER_SEC + HZ - 1) / HZ);
}
static int
-posix_cpu_clock_set(const clockid_t which_clock, const struct timespec64 *tp)
+posix_cpu_clock_set(const clockid_t clock, const struct timespec64 *tp)
{
+ int error = validate_clock_permissions(clock);
+
/*
* You can never reset a CPU clock, but we check for other errors
* in the call before failing with EPERM.
*/
- int error = check_clock(which_clock);
- if (error == 0) {
- error = -EPERM;
- }
- return error;
+ return error ? : -EPERM;
}
-
/*
- * Sample a per-thread clock for the given task.
+ * Sample a per-thread clock for the given task. clkid is validated.
*/
-static int cpu_clock_sample(const clockid_t which_clock,
- struct task_struct *p, u64 *sample)
+static u64 cpu_clock_sample(const clockid_t clkid, struct task_struct *p)
{
- switch (CPUCLOCK_WHICH(which_clock)) {
- default:
- return -EINVAL;
+ u64 utime, stime;
+
+ if (clkid == CPUCLOCK_SCHED)
+ return task_sched_runtime(p);
+
+ task_cputime(p, &utime, &stime);
+
+ switch (clkid) {
case CPUCLOCK_PROF:
- *sample = prof_ticks(p);
- break;
+ return utime + stime;
case CPUCLOCK_VIRT:
- *sample = virt_ticks(p);
- break;
- case CPUCLOCK_SCHED:
- *sample = task_sched_runtime(p);
- break;
+ return utime;
+ default:
+ WARN_ON_ONCE(1);
}
return 0;
}
+static inline void store_samples(u64 *samples, u64 stime, u64 utime, u64 rtime)
+{
+ samples[CPUCLOCK_PROF] = stime + utime;
+ samples[CPUCLOCK_VIRT] = utime;
+ samples[CPUCLOCK_SCHED] = rtime;
+}
+
+static void task_sample_cputime(struct task_struct *p, u64 *samples)
+{
+ u64 stime, utime;
+
+ task_cputime(p, &utime, &stime);
+ store_samples(samples, stime, utime, p->se.sum_exec_runtime);
+}
+
+static void proc_sample_cputime_atomic(struct task_cputime_atomic *at,
+ u64 *samples)
+{
+ u64 stime, utime, rtime;
+
+ utime = atomic64_read(&at->utime);
+ stime = atomic64_read(&at->stime);
+ rtime = atomic64_read(&at->sum_exec_runtime);
+ store_samples(samples, stime, utime, rtime);
+}
+
/*
* Set cputime to sum_cputime if sum_cputime > cputime. Use cmpxchg
* to avoid race conditions with concurrent updates to cputime.
}
}
-static void update_gt_cputime(struct task_cputime_atomic *cputime_atomic, struct task_cputime *sum)
+static void update_gt_cputime(struct task_cputime_atomic *cputime_atomic,
+ struct task_cputime *sum)
{
__update_gt_cputime(&cputime_atomic->utime, sum->utime);
__update_gt_cputime(&cputime_atomic->stime, sum->stime);
__update_gt_cputime(&cputime_atomic->sum_exec_runtime, sum->sum_exec_runtime);
}
-/* Sample task_cputime_atomic values in "atomic_timers", store results in "times". */
-static inline void sample_cputime_atomic(struct task_cputime *times,
- struct task_cputime_atomic *atomic_times)
+/**
+ * thread_group_sample_cputime - Sample cputime for a given task
+ * @tsk: Task for which cputime needs to be started
+ * @iimes: Storage for time samples
+ *
+ * Called from sys_getitimer() to calculate the expiry time of an active
+ * timer. That means group cputime accounting is already active. Called
+ * with task sighand lock held.
+ *
+ * Updates @times with an uptodate sample of the thread group cputimes.
+ */
+void thread_group_sample_cputime(struct task_struct *tsk, u64 *samples)
{
- times->utime = atomic64_read(&atomic_times->utime);
- times->stime = atomic64_read(&atomic_times->stime);
- times->sum_exec_runtime = atomic64_read(&atomic_times->sum_exec_runtime);
+ struct thread_group_cputimer *cputimer = &tsk->signal->cputimer;
+ struct posix_cputimers *pct = &tsk->signal->posix_cputimers;
+
+ WARN_ON_ONCE(!pct->timers_active);
+
+ proc_sample_cputime_atomic(&cputimer->cputime_atomic, samples);
}
-void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times)
+/**
+ * thread_group_start_cputime - Start cputime and return a sample
+ * @tsk: Task for which cputime needs to be started
+ * @samples: Storage for time samples
+ *
+ * The thread group cputime accouting is avoided when there are no posix
+ * CPU timers armed. Before starting a timer it's required to check whether
+ * the time accounting is active. If not, a full update of the atomic
+ * accounting store needs to be done and the accounting enabled.
+ *
+ * Updates @times with an uptodate sample of the thread group cputimes.
+ */
+static void thread_group_start_cputime(struct task_struct *tsk, u64 *samples)
{
struct thread_group_cputimer *cputimer = &tsk->signal->cputimer;
- struct task_cputime sum;
+ struct posix_cputimers *pct = &tsk->signal->posix_cputimers;
/* Check if cputimer isn't running. This is accessed without locking. */
- if (!READ_ONCE(cputimer->running)) {
+ if (!READ_ONCE(pct->timers_active)) {
+ struct task_cputime sum;
+
/*
* The POSIX timer interface allows for absolute time expiry
* values through the TIMER_ABSTIME flag, therefore we have
update_gt_cputime(&cputimer->cputime_atomic, &sum);
/*
- * We're setting cputimer->running without a lock. Ensure
- * this only gets written to in one operation. We set
- * running after update_gt_cputime() as a small optimization,
- * but barriers are not required because update_gt_cputime()
+ * We're setting timers_active without a lock. Ensure this
+ * only gets written to in one operation. We set it after
+ * update_gt_cputime() as a small optimization, but
+ * barriers are not required because update_gt_cputime()
* can handle concurrent updates.
*/
- WRITE_ONCE(cputimer->running, true);
+ WRITE_ONCE(pct->timers_active, true);
}
- sample_cputime_atomic(times, &cputimer->cputime_atomic);
+ proc_sample_cputime_atomic(&cputimer->cputime_atomic, samples);
}
-/*
- * Sample a process (thread group) clock for the given group_leader task.
- * Must be called with task sighand lock held for safe while_each_thread()
- * traversal.
- */
-static int cpu_clock_sample_group(const clockid_t which_clock,
- struct task_struct *p,
- u64 *sample)
+static void __thread_group_cputime(struct task_struct *tsk, u64 *samples)
{
- struct task_cputime cputime;
+ struct task_cputime ct;
- switch (CPUCLOCK_WHICH(which_clock)) {
- default:
- return -EINVAL;
- case CPUCLOCK_PROF:
- thread_group_cputime(p, &cputime);
- *sample = cputime.utime + cputime.stime;
- break;
- case CPUCLOCK_VIRT:
- thread_group_cputime(p, &cputime);
- *sample = cputime.utime;
- break;
- case CPUCLOCK_SCHED:
- thread_group_cputime(p, &cputime);
- *sample = cputime.sum_exec_runtime;
- break;
- }
- return 0;
+ thread_group_cputime(tsk, &ct);
+ store_samples(samples, ct.stime, ct.utime, ct.sum_exec_runtime);
}
-static int posix_cpu_clock_get_task(struct task_struct *tsk,
- const clockid_t which_clock,
- struct timespec64 *tp)
+/*
+ * Sample a process (thread group) clock for the given task clkid. If the
+ * group's cputime accounting is already enabled, read the atomic
+ * store. Otherwise a full update is required. Task's sighand lock must be
+ * held to protect the task traversal on a full update. clkid is already
+ * validated.
+ */
+static u64 cpu_clock_sample_group(const clockid_t clkid, struct task_struct *p,
+ bool start)
{
- int err = -EINVAL;
- u64 rtn;
+ struct thread_group_cputimer *cputimer = &p->signal->cputimer;
+ struct posix_cputimers *pct = &p->signal->posix_cputimers;
+ u64 samples[CPUCLOCK_MAX];
- if (CPUCLOCK_PERTHREAD(which_clock)) {
- if (same_thread_group(tsk, current))
- err = cpu_clock_sample(which_clock, tsk, &rtn);
+ if (!READ_ONCE(pct->timers_active)) {
+ if (start)
+ thread_group_start_cputime(p, samples);
+ else
+ __thread_group_cputime(p, samples);
} else {
- if (tsk == current || thread_group_leader(tsk))
- err = cpu_clock_sample_group(which_clock, tsk, &rtn);
+ proc_sample_cputime_atomic(&cputimer->cputime_atomic, samples);
}
- if (!err)
- *tp = ns_to_timespec64(rtn);
-
- return err;
+ return samples[clkid];
}
-
-static int posix_cpu_clock_get(const clockid_t which_clock, struct timespec64 *tp)
+static int posix_cpu_clock_get(const clockid_t clock, struct timespec64 *tp)
{
- const pid_t pid = CPUCLOCK_PID(which_clock);
- int err = -EINVAL;
+ const clockid_t clkid = CPUCLOCK_WHICH(clock);
+ struct task_struct *tsk;
+ u64 t;
- if (pid == 0) {
- /*
- * Special case constant value for our own clocks.
- * We don't have to do any lookup to find ourselves.
- */
- err = posix_cpu_clock_get_task(current, which_clock, tp);
- } else {
- /*
- * Find the given PID, and validate that the caller
- * should be able to see it.
- */
- struct task_struct *p;
- rcu_read_lock();
- p = find_task_by_vpid(pid);
- if (p)
- err = posix_cpu_clock_get_task(p, which_clock, tp);
- rcu_read_unlock();
- }
+ tsk = get_task_for_clock_get(clock);
+ if (!tsk)
+ return -EINVAL;
- return err;
+ if (CPUCLOCK_PERTHREAD(clock))
+ t = cpu_clock_sample(clkid, tsk);
+ else
+ t = cpu_clock_sample_group(clkid, tsk, false);
+ put_task_struct(tsk);
+
+ *tp = ns_to_timespec64(t);
+ return 0;
}
/*
*/
static int posix_cpu_timer_create(struct k_itimer *new_timer)
{
- int ret = 0;
- const pid_t pid = CPUCLOCK_PID(new_timer->it_clock);
- struct task_struct *p;
+ struct task_struct *p = get_task_for_clock(new_timer->it_clock);
- if (CPUCLOCK_WHICH(new_timer->it_clock) >= CPUCLOCK_MAX)
+ if (!p)
return -EINVAL;
new_timer->kclock = &clock_posix_cpu;
-
- INIT_LIST_HEAD(&new_timer->it.cpu.entry);
-
- rcu_read_lock();
- if (CPUCLOCK_PERTHREAD(new_timer->it_clock)) {
- if (pid == 0) {
- p = current;
- } else {
- p = find_task_by_vpid(pid);
- if (p && !same_thread_group(p, current))
- p = NULL;
- }
- } else {
- if (pid == 0) {
- p = current->group_leader;
- } else {
- p = find_task_by_vpid(pid);
- if (p && !has_group_leader_pid(p))
- p = NULL;
- }
- }
+ timerqueue_init(&new_timer->it.cpu.node);
new_timer->it.cpu.task = p;
- if (p) {
- get_task_struct(p);
- } else {
- ret = -EINVAL;
- }
- rcu_read_unlock();
-
- return ret;
+ return 0;
}
/*
*/
static int posix_cpu_timer_del(struct k_itimer *timer)
{
- int ret = 0;
- unsigned long flags;
+ struct cpu_timer *ctmr = &timer->it.cpu;
+ struct task_struct *p = ctmr->task;
struct sighand_struct *sighand;
- struct task_struct *p = timer->it.cpu.task;
+ unsigned long flags;
+ int ret = 0;
- WARN_ON_ONCE(p == NULL);
+ if (WARN_ON_ONCE(!p))
+ return -EINVAL;
/*
* Protect against sighand release/switch in exit/exec and process/
sighand = lock_task_sighand(p, &flags);
if (unlikely(sighand == NULL)) {
/*
- * We raced with the reaping of the task.
- * The deletion should have cleared us off the list.
+ * This raced with the reaping of the task. The exit cleanup
+ * should have removed this timer from the timer queue.
*/
- WARN_ON_ONCE(!list_empty(&timer->it.cpu.entry));
+ WARN_ON_ONCE(ctmr->head || timerqueue_node_queued(&ctmr->node));
} else {
if (timer->it.cpu.firing)
ret = TIMER_RETRY;
else
- list_del(&timer->it.cpu.entry);
+ cpu_timer_dequeue(ctmr);
unlock_task_sighand(p, &flags);
}
return ret;
}
-static void cleanup_timers_list(struct list_head *head)
+static void cleanup_timerqueue(struct timerqueue_head *head)
{
- struct cpu_timer_list *timer, *next;
+ struct timerqueue_node *node;
+ struct cpu_timer *ctmr;
- list_for_each_entry_safe(timer, next, head, entry)
- list_del_init(&timer->entry);
+ while ((node = timerqueue_getnext(head))) {
+ timerqueue_del(head, node);
+ ctmr = container_of(node, struct cpu_timer, node);
+ ctmr->head = NULL;
+ }
}
/*
- * Clean out CPU timers still ticking when a thread exited. The task
- * pointer is cleared, and the expiry time is replaced with the residual
- * time for later timer_gettime calls to return.
+ * Clean out CPU timers which are still armed when a thread exits. The
+ * timers are only removed from the list. No other updates are done. The
+ * corresponding posix timers are still accessible, but cannot be rearmed.
+ *
* This must be called with the siglock held.
*/
-static void cleanup_timers(struct list_head *head)
+static void cleanup_timers(struct posix_cputimers *pct)
{
- cleanup_timers_list(head);
- cleanup_timers_list(++head);
- cleanup_timers_list(++head);
+ cleanup_timerqueue(&pct->bases[CPUCLOCK_PROF].tqhead);
+ cleanup_timerqueue(&pct->bases[CPUCLOCK_VIRT].tqhead);
+ cleanup_timerqueue(&pct->bases[CPUCLOCK_SCHED].tqhead);
}
/*
*/
void posix_cpu_timers_exit(struct task_struct *tsk)
{
- cleanup_timers(tsk->cpu_timers);
+ cleanup_timers(&tsk->posix_cputimers);
}
void posix_cpu_timers_exit_group(struct task_struct *tsk)
{
- cleanup_timers(tsk->signal->cpu_timers);
-}
-
-static inline int expires_gt(u64 expires, u64 new_exp)
-{
- return expires == 0 || expires > new_exp;
+ cleanup_timers(&tsk->signal->posix_cputimers);
}
/*
*/
static void arm_timer(struct k_itimer *timer)
{
- struct task_struct *p = timer->it.cpu.task;
- struct list_head *head, *listpos;
- struct task_cputime *cputime_expires;
- struct cpu_timer_list *const nt = &timer->it.cpu;
- struct cpu_timer_list *next;
-
- if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
- head = p->cpu_timers;
- cputime_expires = &p->cputime_expires;
- } else {
- head = p->signal->cpu_timers;
- cputime_expires = &p->signal->cputime_expires;
- }
- head += CPUCLOCK_WHICH(timer->it_clock);
-
- listpos = head;
- list_for_each_entry(next, head, entry) {
- if (nt->expires < next->expires)
- break;
- listpos = &next->entry;
- }
- list_add(&nt->entry, listpos);
-
- if (listpos == head) {
- u64 exp = nt->expires;
+ int clkidx = CPUCLOCK_WHICH(timer->it_clock);
+ struct cpu_timer *ctmr = &timer->it.cpu;
+ u64 newexp = cpu_timer_getexpires(ctmr);
+ struct task_struct *p = ctmr->task;
+ struct posix_cputimer_base *base;
+
+ if (CPUCLOCK_PERTHREAD(timer->it_clock))
+ base = p->posix_cputimers.bases + clkidx;
+ else
+ base = p->signal->posix_cputimers.bases + clkidx;
+
+ if (!cpu_timer_enqueue(&base->tqhead, ctmr))
+ return;
- /*
- * We are the new earliest-expiring POSIX 1.b timer, hence
- * need to update expiration cache. Take into account that
- * for process timers we share expiration cache with itimers
- * and RLIMIT_CPU and for thread timers with RLIMIT_RTTIME.
- */
+ /*
+ * We are the new earliest-expiring POSIX 1.b timer, hence
+ * need to update expiration cache. Take into account that
+ * for process timers we share expiration cache with itimers
+ * and RLIMIT_CPU and for thread timers with RLIMIT_RTTIME.
+ */
+ if (newexp < base->nextevt)
+ base->nextevt = newexp;
- switch (CPUCLOCK_WHICH(timer->it_clock)) {
- case CPUCLOCK_PROF:
- if (expires_gt(cputime_expires->prof_exp, exp))
- cputime_expires->prof_exp = exp;
- break;
- case CPUCLOCK_VIRT:
- if (expires_gt(cputime_expires->virt_exp, exp))
- cputime_expires->virt_exp = exp;
- break;
- case CPUCLOCK_SCHED:
- if (expires_gt(cputime_expires->sched_exp, exp))
- cputime_expires->sched_exp = exp;
- break;
- }
- if (CPUCLOCK_PERTHREAD(timer->it_clock))
- tick_dep_set_task(p, TICK_DEP_BIT_POSIX_TIMER);
- else
- tick_dep_set_signal(p->signal, TICK_DEP_BIT_POSIX_TIMER);
- }
+ if (CPUCLOCK_PERTHREAD(timer->it_clock))
+ tick_dep_set_task(p, TICK_DEP_BIT_POSIX_TIMER);
+ else
+ tick_dep_set_signal(p->signal, TICK_DEP_BIT_POSIX_TIMER);
}
/*
*/
static void cpu_timer_fire(struct k_itimer *timer)
{
+ struct cpu_timer *ctmr = &timer->it.cpu;
+
if ((timer->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE) {
/*
* User don't want any signal.
*/
- timer->it.cpu.expires = 0;
+ cpu_timer_setexpires(ctmr, 0);
} else if (unlikely(timer->sigq == NULL)) {
/*
* This a special case for clock_nanosleep,
* not a normal timer from sys_timer_create.
*/
wake_up_process(timer->it_process);
- timer->it.cpu.expires = 0;
+ cpu_timer_setexpires(ctmr, 0);
} else if (!timer->it_interval) {
/*
* One-shot timer. Clear it as soon as it's fired.
*/
posix_timer_event(timer, 0);
- timer->it.cpu.expires = 0;
+ cpu_timer_setexpires(ctmr, 0);
} else if (posix_timer_event(timer, ++timer->it_requeue_pending)) {
/*
* The signal did not get queued because the signal
}
}
-/*
- * Sample a process (thread group) timer for the given group_leader task.
- * Must be called with task sighand lock held for safe while_each_thread()
- * traversal.
- */
-static int cpu_timer_sample_group(const clockid_t which_clock,
- struct task_struct *p, u64 *sample)
-{
- struct task_cputime cputime;
-
- thread_group_cputimer(p, &cputime);
- switch (CPUCLOCK_WHICH(which_clock)) {
- default:
- return -EINVAL;
- case CPUCLOCK_PROF:
- *sample = cputime.utime + cputime.stime;
- break;
- case CPUCLOCK_VIRT:
- *sample = cputime.utime;
- break;
- case CPUCLOCK_SCHED:
- *sample = cputime.sum_exec_runtime;
- break;
- }
- return 0;
-}
-
/*
* Guts of sys_timer_settime for CPU timers.
* This is called with the timer locked and interrupts disabled.
static int posix_cpu_timer_set(struct k_itimer *timer, int timer_flags,
struct itimerspec64 *new, struct itimerspec64 *old)
{
- unsigned long flags;
- struct sighand_struct *sighand;
- struct task_struct *p = timer->it.cpu.task;
+ clockid_t clkid = CPUCLOCK_WHICH(timer->it_clock);
u64 old_expires, new_expires, old_incr, val;
- int ret;
+ struct cpu_timer *ctmr = &timer->it.cpu;
+ struct task_struct *p = ctmr->task;
+ struct sighand_struct *sighand;
+ unsigned long flags;
+ int ret = 0;
- WARN_ON_ONCE(p == NULL);
+ if (WARN_ON_ONCE(!p))
+ return -EINVAL;
/*
* Use the to_ktime conversion because that clamps the maximum
* If p has just been reaped, we can no
* longer get any information about it at all.
*/
- if (unlikely(sighand == NULL)) {
+ if (unlikely(sighand == NULL))
return -ESRCH;
- }
/*
* Disarm any old timer after extracting its expiry time.
*/
-
- ret = 0;
old_incr = timer->it_interval;
- old_expires = timer->it.cpu.expires;
+ old_expires = cpu_timer_getexpires(ctmr);
+
if (unlikely(timer->it.cpu.firing)) {
timer->it.cpu.firing = -1;
ret = TIMER_RETRY;
- } else
- list_del_init(&timer->it.cpu.entry);
+ } else {
+ cpu_timer_dequeue(ctmr);
+ }
/*
* We need to sample the current value to convert the new
* times (in arm_timer). With an absolute time, we must
* check if it's already passed. In short, we need a sample.
*/
- if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
- cpu_clock_sample(timer->it_clock, p, &val);
- } else {
- cpu_timer_sample_group(timer->it_clock, p, &val);
- }
+ if (CPUCLOCK_PERTHREAD(timer->it_clock))
+ val = cpu_clock_sample(clkid, p);
+ else
+ val = cpu_clock_sample_group(clkid, p, true);
if (old) {
if (old_expires == 0) {
old->it_value.tv_nsec = 0;
} else {
/*
- * Update the timer in case it has
- * overrun already. If it has,
- * we'll report it as having overrun
- * and with the next reloaded timer
- * already ticking, though we are
- * swallowing that pending
- * notification here to install the
- * new setting.
+ * Update the timer in case it has overrun already.
+ * If it has, we'll report it as having overrun and
+ * with the next reloaded timer already ticking,
+ * though we are swallowing that pending
+ * notification here to install the new setting.
*/
- bump_cpu_timer(timer, val);
- if (val < timer->it.cpu.expires) {
- old_expires = timer->it.cpu.expires - val;
+ u64 exp = bump_cpu_timer(timer, val);
+
+ if (val < exp) {
+ old_expires = exp - val;
old->it_value = ns_to_timespec64(old_expires);
} else {
old->it_value.tv_nsec = 1;
* For a timer with no notification action, we don't actually
* arm the timer (we'll just fake it for timer_gettime).
*/
- timer->it.cpu.expires = new_expires;
+ cpu_timer_setexpires(ctmr, new_expires);
if (new_expires != 0 && val < new_expires) {
arm_timer(timer);
}
static void posix_cpu_timer_get(struct k_itimer *timer, struct itimerspec64 *itp)
{
- u64 now;
- struct task_struct *p = timer->it.cpu.task;
+ clockid_t clkid = CPUCLOCK_WHICH(timer->it_clock);
+ struct cpu_timer *ctmr = &timer->it.cpu;
+ u64 now, expires = cpu_timer_getexpires(ctmr);
+ struct task_struct *p = ctmr->task;
- WARN_ON_ONCE(p == NULL);
+ if (WARN_ON_ONCE(!p))
+ return;
/*
* Easy part: convert the reload time.
*/
itp->it_interval = ktime_to_timespec64(timer->it_interval);
- if (!timer->it.cpu.expires)
+ if (!expires)
return;
/*
* Sample the clock to take the difference with the expiry time.
*/
if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
- cpu_clock_sample(timer->it_clock, p, &now);
+ now = cpu_clock_sample(clkid, p);
} else {
struct sighand_struct *sighand;
unsigned long flags;
/*
* The process has been reaped.
* We can't even collect a sample any more.
- * Call the timer disarmed, nothing else to do.
+ * Disarm the timer, nothing else to do.
*/
- timer->it.cpu.expires = 0;
+ cpu_timer_setexpires(ctmr, 0);
return;
} else {
- cpu_timer_sample_group(timer->it_clock, p, &now);
+ now = cpu_clock_sample_group(clkid, p, false);
unlock_task_sighand(p, &flags);
}
}
- if (now < timer->it.cpu.expires) {
- itp->it_value = ns_to_timespec64(timer->it.cpu.expires - now);
+ if (now < expires) {
+ itp->it_value = ns_to_timespec64(expires - now);
} else {
/*
* The timer should have expired already, but the firing
}
}
-static unsigned long long
-check_timers_list(struct list_head *timers,
- struct list_head *firing,
- unsigned long long curr)
-{
- int maxfire = 20;
+#define MAX_COLLECTED 20
- while (!list_empty(timers)) {
- struct cpu_timer_list *t;
+static u64 collect_timerqueue(struct timerqueue_head *head,
+ struct list_head *firing, u64 now)
+{
+ struct timerqueue_node *next;
+ int i = 0;
+
+ while ((next = timerqueue_getnext(head))) {
+ struct cpu_timer *ctmr;
+ u64 expires;
+
+ ctmr = container_of(next, struct cpu_timer, node);
+ expires = cpu_timer_getexpires(ctmr);
+ /* Limit the number of timers to expire at once */
+ if (++i == MAX_COLLECTED || now < expires)
+ return expires;
+
+ ctmr->firing = 1;
+ cpu_timer_dequeue(ctmr);
+ list_add_tail(&ctmr->elist, firing);
+ }
- t = list_first_entry(timers, struct cpu_timer_list, entry);
+ return U64_MAX;
+}
- if (!--maxfire || curr < t->expires)
- return t->expires;
+static void collect_posix_cputimers(struct posix_cputimers *pct, u64 *samples,
+ struct list_head *firing)
+{
+ struct posix_cputimer_base *base = pct->bases;
+ int i;
- t->firing = 1;
- list_move_tail(&t->entry, firing);
+ for (i = 0; i < CPUCLOCK_MAX; i++, base++) {
+ base->nextevt = collect_timerqueue(&base->tqhead, firing,
+ samples[i]);
}
-
- return 0;
}
static inline void check_dl_overrun(struct task_struct *tsk)
}
}
+static bool check_rlimit(u64 time, u64 limit, int signo, bool rt, bool hard)
+{
+ if (time < limit)
+ return false;
+
+ if (print_fatal_signals) {
+ pr_info("%s Watchdog Timeout (%s): %s[%d]\n",
+ rt ? "RT" : "CPU", hard ? "hard" : "soft",
+ current->comm, task_pid_nr(current));
+ }
+ __group_send_sig_info(signo, SEND_SIG_PRIV, current);
+ return true;
+}
+
/*
* Check for any per-thread CPU timers that have fired and move them off
* the tsk->cpu_timers[N] list onto the firing list. Here we update the
static void check_thread_timers(struct task_struct *tsk,
struct list_head *firing)
{
- struct list_head *timers = tsk->cpu_timers;
- struct task_cputime *tsk_expires = &tsk->cputime_expires;
- u64 expires;
+ struct posix_cputimers *pct = &tsk->posix_cputimers;
+ u64 samples[CPUCLOCK_MAX];
unsigned long soft;
if (dl_task(tsk))
check_dl_overrun(tsk);
- /*
- * If cputime_expires is zero, then there are no active
- * per thread CPU timers.
- */
- if (task_cputime_zero(&tsk->cputime_expires))
+ if (expiry_cache_is_inactive(pct))
return;
- expires = check_timers_list(timers, firing, prof_ticks(tsk));
- tsk_expires->prof_exp = expires;
-
- expires = check_timers_list(++timers, firing, virt_ticks(tsk));
- tsk_expires->virt_exp = expires;
-
- tsk_expires->sched_exp = check_timers_list(++timers, firing,
- tsk->se.sum_exec_runtime);
+ task_sample_cputime(tsk, samples);
+ collect_posix_cputimers(pct, samples, firing);
/*
* Check for the special case thread timers.
*/
soft = task_rlimit(tsk, RLIMIT_RTTIME);
if (soft != RLIM_INFINITY) {
+ /* Task RT timeout is accounted in jiffies. RTTIME is usec */
+ unsigned long rttime = tsk->rt.timeout * (USEC_PER_SEC / HZ);
unsigned long hard = task_rlimit_max(tsk, RLIMIT_RTTIME);
+ /* At the hard limit, send SIGKILL. No further action. */
if (hard != RLIM_INFINITY &&
- tsk->rt.timeout > DIV_ROUND_UP(hard, USEC_PER_SEC/HZ)) {
- /*
- * At the hard limit, we just die.
- * No need to calculate anything else now.
- */
- if (print_fatal_signals) {
- pr_info("CPU Watchdog Timeout (hard): %s[%d]\n",
- tsk->comm, task_pid_nr(tsk));
- }
- __group_send_sig_info(SIGKILL, SEND_SIG_PRIV, tsk);
+ check_rlimit(rttime, hard, SIGKILL, true, true))
return;
- }
- if (tsk->rt.timeout > DIV_ROUND_UP(soft, USEC_PER_SEC/HZ)) {
- /*
- * At the soft limit, send a SIGXCPU every second.
- */
- if (soft < hard) {
- soft += USEC_PER_SEC;
- tsk->signal->rlim[RLIMIT_RTTIME].rlim_cur =
- soft;
- }
- if (print_fatal_signals) {
- pr_info("RT Watchdog Timeout (soft): %s[%d]\n",
- tsk->comm, task_pid_nr(tsk));
- }
- __group_send_sig_info(SIGXCPU, SEND_SIG_PRIV, tsk);
+
+ /* At the soft limit, send a SIGXCPU every second */
+ if (check_rlimit(rttime, soft, SIGXCPU, true, false)) {
+ soft += USEC_PER_SEC;
+ tsk->signal->rlim[RLIMIT_RTTIME].rlim_cur = soft;
}
}
- if (task_cputime_zero(tsk_expires))
+
+ if (expiry_cache_is_inactive(pct))
tick_dep_clear_task(tsk, TICK_DEP_BIT_POSIX_TIMER);
}
static inline void stop_process_timers(struct signal_struct *sig)
{
- struct thread_group_cputimer *cputimer = &sig->cputimer;
+ struct posix_cputimers *pct = &sig->posix_cputimers;
- /* Turn off cputimer->running. This is done without locking. */
- WRITE_ONCE(cputimer->running, false);
+ /* Turn off the active flag. This is done without locking. */
+ WRITE_ONCE(pct->timers_active, false);
tick_dep_clear_signal(sig, TICK_DEP_BIT_POSIX_TIMER);
}
__group_send_sig_info(signo, SEND_SIG_PRIV, tsk);
}
- if (it->expires && (!*expires || it->expires < *expires))
+ if (it->expires && it->expires < *expires)
*expires = it->expires;
}
struct list_head *firing)
{
struct signal_struct *const sig = tsk->signal;
- u64 utime, ptime, virt_expires, prof_expires;
- u64 sum_sched_runtime, sched_expires;
- struct list_head *timers = sig->cpu_timers;
- struct task_cputime cputime;
+ struct posix_cputimers *pct = &sig->posix_cputimers;
+ u64 samples[CPUCLOCK_MAX];
unsigned long soft;
/*
- * If cputimer is not running, then there are no active
- * process wide timers (POSIX 1.b, itimers, RLIMIT_CPU).
+ * If there are no active process wide timers (POSIX 1.b, itimers,
+ * RLIMIT_CPU) nothing to check. Also skip the process wide timer
+ * processing when there is already another task handling them.
*/
- if (!READ_ONCE(tsk->signal->cputimer.running))
+ if (!READ_ONCE(pct->timers_active) || pct->expiry_active)
return;
- /*
+ /*
* Signify that a thread is checking for process timers.
* Write access to this field is protected by the sighand lock.
*/
- sig->cputimer.checking_timer = true;
+ pct->expiry_active = true;
/*
- * Collect the current process totals.
+ * Collect the current process totals. Group accounting is active
+ * so the sample can be taken directly.
*/
- thread_group_cputimer(tsk, &cputime);
- utime = cputime.utime;
- ptime = utime + cputime.stime;
- sum_sched_runtime = cputime.sum_exec_runtime;
-
- prof_expires = check_timers_list(timers, firing, ptime);
- virt_expires = check_timers_list(++timers, firing, utime);
- sched_expires = check_timers_list(++timers, firing, sum_sched_runtime);
+ proc_sample_cputime_atomic(&sig->cputimer.cputime_atomic, samples);
+ collect_posix_cputimers(pct, samples, firing);
/*
* Check for the special case process timers.
*/
- check_cpu_itimer(tsk, &sig->it[CPUCLOCK_PROF], &prof_expires, ptime,
- SIGPROF);
- check_cpu_itimer(tsk, &sig->it[CPUCLOCK_VIRT], &virt_expires, utime,
- SIGVTALRM);
+ check_cpu_itimer(tsk, &sig->it[CPUCLOCK_PROF],
+ &pct->bases[CPUCLOCK_PROF].nextevt,
+ samples[CPUCLOCK_PROF], SIGPROF);
+ check_cpu_itimer(tsk, &sig->it[CPUCLOCK_VIRT],
+ &pct->bases[CPUCLOCK_VIRT].nextevt,
+ samples[CPUCLOCK_VIRT], SIGVTALRM);
+
soft = task_rlimit(tsk, RLIMIT_CPU);
if (soft != RLIM_INFINITY) {
- unsigned long psecs = div_u64(ptime, NSEC_PER_SEC);
+ /* RLIMIT_CPU is in seconds. Samples are nanoseconds */
unsigned long hard = task_rlimit_max(tsk, RLIMIT_CPU);
- u64 x;
- if (psecs >= hard) {
- /*
- * At the hard limit, we just die.
- * No need to calculate anything else now.
- */
- if (print_fatal_signals) {
- pr_info("RT Watchdog Timeout (hard): %s[%d]\n",
- tsk->comm, task_pid_nr(tsk));
- }
- __group_send_sig_info(SIGKILL, SEND_SIG_PRIV, tsk);
+ u64 ptime = samples[CPUCLOCK_PROF];
+ u64 softns = (u64)soft * NSEC_PER_SEC;
+ u64 hardns = (u64)hard * NSEC_PER_SEC;
+
+ /* At the hard limit, send SIGKILL. No further action. */
+ if (hard != RLIM_INFINITY &&
+ check_rlimit(ptime, hardns, SIGKILL, false, true))
return;
+
+ /* At the soft limit, send a SIGXCPU every second */
+ if (check_rlimit(ptime, softns, SIGXCPU, false, false)) {
+ sig->rlim[RLIMIT_CPU].rlim_cur = soft + 1;
+ softns += NSEC_PER_SEC;
}
- if (psecs >= soft) {
- /*
- * At the soft limit, send a SIGXCPU every second.
- */
- if (print_fatal_signals) {
- pr_info("CPU Watchdog Timeout (soft): %s[%d]\n",
- tsk->comm, task_pid_nr(tsk));
- }
- __group_send_sig_info(SIGXCPU, SEND_SIG_PRIV, tsk);
- if (soft < hard) {
- soft++;
- sig->rlim[RLIMIT_CPU].rlim_cur = soft;
- }
- }
- x = soft * NSEC_PER_SEC;
- if (!prof_expires || x < prof_expires)
- prof_expires = x;
+
+ /* Update the expiry cache */
+ if (softns < pct->bases[CPUCLOCK_PROF].nextevt)
+ pct->bases[CPUCLOCK_PROF].nextevt = softns;
}
- sig->cputime_expires.prof_exp = prof_expires;
- sig->cputime_expires.virt_exp = virt_expires;
- sig->cputime_expires.sched_exp = sched_expires;
- if (task_cputime_zero(&sig->cputime_expires))
+ if (expiry_cache_is_inactive(pct))
stop_process_timers(sig);
- sig->cputimer.checking_timer = false;
+ pct->expiry_active = false;
}
/*
*/
static void posix_cpu_timer_rearm(struct k_itimer *timer)
{
+ clockid_t clkid = CPUCLOCK_WHICH(timer->it_clock);
+ struct cpu_timer *ctmr = &timer->it.cpu;
+ struct task_struct *p = ctmr->task;
struct sighand_struct *sighand;
unsigned long flags;
- struct task_struct *p = timer->it.cpu.task;
u64 now;
- WARN_ON_ONCE(p == NULL);
+ if (WARN_ON_ONCE(!p))
+ return;
/*
* Fetch the current sample and update the timer's expiry time.
*/
if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
- cpu_clock_sample(timer->it_clock, p, &now);
+ now = cpu_clock_sample(clkid, p);
bump_cpu_timer(timer, now);
if (unlikely(p->exit_state))
return;
* The process has been reaped.
* We can't even collect a sample any more.
*/
- timer->it.cpu.expires = 0;
+ cpu_timer_setexpires(ctmr, 0);
return;
} else if (unlikely(p->exit_state) && thread_group_empty(p)) {
/* If the process is dying, no need to rearm */
goto unlock;
}
- cpu_timer_sample_group(timer->it_clock, p, &now);
+ now = cpu_clock_sample_group(clkid, p, true);
bump_cpu_timer(timer, now);
/* Leave the sighand locked for the call below. */
}
}
/**
- * task_cputime_expired - Compare two task_cputime entities.
+ * task_cputimers_expired - Check whether posix CPU timers are expired
*
- * @sample: The task_cputime structure to be checked for expiration.
- * @expires: Expiration times, against which @sample will be checked.
+ * @samples: Array of current samples for the CPUCLOCK clocks
+ * @pct: Pointer to a posix_cputimers container
*
- * Checks @sample against @expires to see if any field of @sample has expired.
- * Returns true if any field of the former is greater than the corresponding
- * field of the latter if the latter field is set. Otherwise returns false.
+ * Returns true if any member of @samples is greater than the corresponding
+ * member of @pct->bases[CLK].nextevt. False otherwise
*/
-static inline int task_cputime_expired(const struct task_cputime *sample,
- const struct task_cputime *expires)
+static inline bool
+task_cputimers_expired(const u64 *sample, struct posix_cputimers *pct)
{
- if (expires->utime && sample->utime >= expires->utime)
- return 1;
- if (expires->stime && sample->utime + sample->stime >= expires->stime)
- return 1;
- if (expires->sum_exec_runtime != 0 &&
- sample->sum_exec_runtime >= expires->sum_exec_runtime)
- return 1;
- return 0;
+ int i;
+
+ for (i = 0; i < CPUCLOCK_MAX; i++) {
+ if (sample[i] >= pct->bases[i].nextevt)
+ return true;
+ }
+ return false;
}
/**
* timers and compare them with the corresponding expiration times. Return
* true if a timer has expired, else return false.
*/
-static inline int fastpath_timer_check(struct task_struct *tsk)
+static inline bool fastpath_timer_check(struct task_struct *tsk)
{
+ struct posix_cputimers *pct = &tsk->posix_cputimers;
struct signal_struct *sig;
- if (!task_cputime_zero(&tsk->cputime_expires)) {
- struct task_cputime task_sample;
+ if (!expiry_cache_is_inactive(pct)) {
+ u64 samples[CPUCLOCK_MAX];
- task_cputime(tsk, &task_sample.utime, &task_sample.stime);
- task_sample.sum_exec_runtime = tsk->se.sum_exec_runtime;
- if (task_cputime_expired(&task_sample, &tsk->cputime_expires))
- return 1;
+ task_sample_cputime(tsk, samples);
+ if (task_cputimers_expired(samples, pct))
+ return true;
}
sig = tsk->signal;
+ pct = &sig->posix_cputimers;
/*
- * Check if thread group timers expired when the cputimer is
- * running and no other thread in the group is already checking
- * for thread group cputimers. These fields are read without the
- * sighand lock. However, this is fine because this is meant to
- * be a fastpath heuristic to determine whether we should try to
- * acquire the sighand lock to check/handle timers.
+ * Check if thread group timers expired when timers are active and
+ * no other thread in the group is already handling expiry for
+ * thread group cputimers. These fields are read without the
+ * sighand lock. However, this is fine because this is meant to be
+ * a fastpath heuristic to determine whether we should try to
+ * acquire the sighand lock to handle timer expiry.
*
- * In the worst case scenario, if 'running' or 'checking_timer' gets
- * set but the current thread doesn't see the change yet, we'll wait
- * until the next thread in the group gets a scheduler interrupt to
- * handle the timer. This isn't an issue in practice because these
- * types of delays with signals actually getting sent are expected.
+ * In the worst case scenario, if concurrently timers_active is set
+ * or expiry_active is cleared, but the current thread doesn't see
+ * the change yet, the timer checks are delayed until the next
+ * thread in the group gets a scheduler interrupt to handle the
+ * timer. This isn't an issue in practice because these types of
+ * delays with signals actually getting sent are expected.
*/
- if (READ_ONCE(sig->cputimer.running) &&
- !READ_ONCE(sig->cputimer.checking_timer)) {
- struct task_cputime group_sample;
+ if (READ_ONCE(pct->timers_active) && !READ_ONCE(pct->expiry_active)) {
+ u64 samples[CPUCLOCK_MAX];
- sample_cputime_atomic(&group_sample, &sig->cputimer.cputime_atomic);
+ proc_sample_cputime_atomic(&sig->cputimer.cputime_atomic,
+ samples);
- if (task_cputime_expired(&group_sample, &sig->cputime_expires))
- return 1;
+ if (task_cputimers_expired(samples, pct))
+ return true;
}
if (dl_task(tsk) && tsk->dl.dl_overrun)
- return 1;
+ return true;
- return 0;
+ return false;
}
/*
* already updated our counts. We need to check if any timers fire now.
* Interrupts are disabled.
*/
-void run_posix_cpu_timers(struct task_struct *tsk)
+void run_posix_cpu_timers(void)
{
- LIST_HEAD(firing);
+ struct task_struct *tsk = current;
struct k_itimer *timer, *next;
unsigned long flags;
+ LIST_HEAD(firing);
lockdep_assert_irqs_disabled();
* each timer's lock before clearing its firing flag, so no
* timer call will interfere.
*/
- list_for_each_entry_safe(timer, next, &firing, it.cpu.entry) {
+ list_for_each_entry_safe(timer, next, &firing, it.cpu.elist) {
int cpu_firing;
spin_lock(&timer->it_lock);
- list_del_init(&timer->it.cpu.entry);
+ list_del_init(&timer->it.cpu.elist);
cpu_firing = timer->it.cpu.firing;
timer->it.cpu.firing = 0;
/*
* Set one of the process-wide special case CPU timers or RLIMIT_CPU.
* The tsk->sighand->siglock must be held by the caller.
*/
-void set_process_cpu_timer(struct task_struct *tsk, unsigned int clock_idx,
+void set_process_cpu_timer(struct task_struct *tsk, unsigned int clkid,
u64 *newval, u64 *oldval)
{
- u64 now;
- int ret;
+ u64 now, *nextevt;
+
+ if (WARN_ON_ONCE(clkid >= CPUCLOCK_SCHED))
+ return;
- WARN_ON_ONCE(clock_idx == CPUCLOCK_SCHED);
- ret = cpu_timer_sample_group(clock_idx, tsk, &now);
+ nextevt = &tsk->signal->posix_cputimers.bases[clkid].nextevt;
+ now = cpu_clock_sample_group(clkid, tsk, true);
- if (oldval && ret != -EINVAL) {
+ if (oldval) {
/*
* We are setting itimer. The *oldval is absolute and we update
* it to be relative, *newval argument is relative and we update
}
/*
- * Update expiration cache if we are the earliest timer, or eventually
- * RLIMIT_CPU limit is earlier than prof_exp cpu timer expire.
+ * Update expiration cache if this is the earliest timer. CPUCLOCK_PROF
+ * expiry cache is also used by RLIMIT_CPU!.
*/
- switch (clock_idx) {
- case CPUCLOCK_PROF:
- if (expires_gt(tsk->signal->cputime_expires.prof_exp, *newval))
- tsk->signal->cputime_expires.prof_exp = *newval;
- break;
- case CPUCLOCK_VIRT:
- if (expires_gt(tsk->signal->cputime_expires.virt_exp, *newval))
- tsk->signal->cputime_expires.virt_exp = *newval;
- break;
- }
+ if (*newval < *nextevt)
+ *nextevt = *newval;
tick_dep_set_signal(tsk->signal, TICK_DEP_BIT_POSIX_TIMER);
}
timer.it_overrun = -1;
error = posix_cpu_timer_create(&timer);
timer.it_process = current;
+
if (!error) {
static struct itimerspec64 zero_it;
struct restart_block *restart;
}
while (!signal_pending(current)) {
- if (timer.it.cpu.expires == 0) {
+ if (!cpu_timer_getexpires(&timer.it.cpu)) {
/*
* Our timer fired and was reset, below
* deletion can not fail.
/*
* We were interrupted by a signal.
*/
- expires = timer.it.cpu.expires;
+ expires = cpu_timer_getexpires(&timer.it.cpu);
error = posix_cpu_timer_set(&timer, 0, &zero_it, &it);
if (!error) {
/*
static void k_itimer_rcu_free(struct rcu_head *head)
{
- struct k_itimer *tmr = container_of(head, struct k_itimer, it.rcu);
+ struct k_itimer *tmr = container_of(head, struct k_itimer, rcu);
kmem_cache_free(posix_timers_cache, tmr);
}
}
put_pid(tmr->it_pid);
sigqueue_free(tmr->sigq);
- call_rcu(&tmr->it.rcu, k_itimer_rcu_free);
+ call_rcu(&tmr->rcu, k_itimer_rcu_free);
}
static int common_timer_create(struct k_itimer *new_timer)
return hrtimer_try_to_cancel(&timr->it.real.timer);
}
+static void common_timer_wait_running(struct k_itimer *timer)
+{
+ hrtimer_cancel_wait_running(&timer->it.real.timer);
+}
+
+/*
+ * On PREEMPT_RT this prevent priority inversion against softirq kthread in
+ * case it gets preempted while executing a timer callback. See comments in
+ * hrtimer_cancel_wait_running. For PREEMPT_RT=n this just results in a
+ * cpu_relax().
+ */
+static struct k_itimer *timer_wait_running(struct k_itimer *timer,
+ unsigned long *flags)
+{
+ const struct k_clock *kc = READ_ONCE(timer->kclock);
+ timer_t timer_id = READ_ONCE(timer->it_id);
+
+ /* Prevent kfree(timer) after dropping the lock */
+ rcu_read_lock();
+ unlock_timer(timer, *flags);
+
+ if (!WARN_ON_ONCE(!kc->timer_wait_running))
+ kc->timer_wait_running(timer);
+
+ rcu_read_unlock();
+ /* Relock the timer. It might be not longer hashed. */
+ return lock_timer(timer_id, flags);
+}
+
/* Set a POSIX.1b interval timer. */
int common_timer_set(struct k_itimer *timr, int flags,
struct itimerspec64 *new_setting,
return 0;
}
-static int do_timer_settime(timer_t timer_id, int flags,
+static int do_timer_settime(timer_t timer_id, int tmr_flags,
struct itimerspec64 *new_spec64,
struct itimerspec64 *old_spec64)
{
const struct k_clock *kc;
struct k_itimer *timr;
- unsigned long flag;
+ unsigned long flags;
int error = 0;
if (!timespec64_valid(&new_spec64->it_interval) ||
if (old_spec64)
memset(old_spec64, 0, sizeof(*old_spec64));
+
+ timr = lock_timer(timer_id, &flags);
retry:
- timr = lock_timer(timer_id, &flag);
if (!timr)
return -EINVAL;
if (WARN_ON_ONCE(!kc || !kc->timer_set))
error = -EINVAL;
else
- error = kc->timer_set(timr, flags, new_spec64, old_spec64);
+ error = kc->timer_set(timr, tmr_flags, new_spec64, old_spec64);
- unlock_timer(timr, flag);
if (error == TIMER_RETRY) {
- old_spec64 = NULL; // We already got the old time...
+ // We already got the old time...
+ old_spec64 = NULL;
+ /* Unlocks and relocks the timer if it still exists */
+ timr = timer_wait_running(timr, &flags);
goto retry;
}
+ unlock_timer(timr, flags);
return error;
}
struct k_itimer *timer;
unsigned long flags;
-retry_delete:
timer = lock_timer(timer_id, &flags);
+
+retry_delete:
if (!timer)
return -EINVAL;
- if (timer_delete_hook(timer) == TIMER_RETRY) {
- unlock_timer(timer, flags);
+ if (unlikely(timer_delete_hook(timer) == TIMER_RETRY)) {
+ /* Unlocks and relocks the timer if it still exists */
+ timer = timer_wait_running(timer, &flags);
goto retry_delete;
}
.timer_forward = common_hrtimer_forward,
.timer_remaining = common_hrtimer_remaining,
.timer_try_to_cancel = common_hrtimer_try_to_cancel,
+ .timer_wait_running = common_timer_wait_running,
.timer_arm = common_hrtimer_arm,
};
.timer_forward = common_hrtimer_forward,
.timer_remaining = common_hrtimer_remaining,
.timer_try_to_cancel = common_hrtimer_try_to_cancel,
+ .timer_wait_running = common_timer_wait_running,
.timer_arm = common_hrtimer_arm,
};
.timer_forward = common_hrtimer_forward,
.timer_remaining = common_hrtimer_remaining,
.timer_try_to_cancel = common_hrtimer_try_to_cancel,
+ .timer_wait_running = common_timer_wait_running,
.timer_arm = common_hrtimer_arm,
};
.timer_forward = common_hrtimer_forward,
.timer_remaining = common_hrtimer_remaining,
.timer_try_to_cancel = common_hrtimer_try_to_cancel,
+ .timer_wait_running = common_timer_wait_running,
.timer_arm = common_hrtimer_arm,
};
int (*timer_try_to_cancel)(struct k_itimer *timr);
void (*timer_arm)(struct k_itimer *timr, ktime_t expires,
bool absolute, bool sigev_none);
+ void (*timer_wait_running)(struct k_itimer *timr);
};
extern const struct k_clock clock_posix_cpu;
* hrtimer_{start/cancel} functions call into tracing,
* calls to these functions must be bound within RCU_NONIDLE.
*/
- RCU_NONIDLE({
+ RCU_NONIDLE(
+ {
bc_moved = hrtimer_try_to_cancel(&bctimer) >= 0;
- if (bc_moved)
+ if (bc_moved) {
hrtimer_start(&bctimer, expires,
- HRTIMER_MODE_ABS_PINNED);});
+ HRTIMER_MODE_ABS_PINNED_HARD);
+ }
+ }
+ );
+
if (bc_moved) {
/* Bind the "device" to the cpu */
bc->bound_on = smp_processor_id();
void tick_setup_hrtimer_broadcast(void)
{
- hrtimer_init(&bctimer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
+ hrtimer_init(&bctimer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_HARD);
bctimer.function = bc_handler;
clockevents_register_device(&ce_broadcast_hrtimer);
}
/* Forward the time to expire in the future */
hrtimer_forward(&ts->sched_timer, now, tick_period);
- if (ts->nohz_mode == NOHZ_MODE_HIGHRES)
- hrtimer_start_expires(&ts->sched_timer, HRTIMER_MODE_ABS_PINNED);
- else
+ if (ts->nohz_mode == NOHZ_MODE_HIGHRES) {
+ hrtimer_start_expires(&ts->sched_timer,
+ HRTIMER_MODE_ABS_PINNED_HARD);
+ } else {
tick_program_event(hrtimer_get_expires(&ts->sched_timer), 1);
+ }
/*
* Reset to make sure next tick stop doesn't get fooled by past
}
if (ts->nohz_mode == NOHZ_MODE_HIGHRES) {
- hrtimer_start(&ts->sched_timer, tick, HRTIMER_MODE_ABS_PINNED);
+ hrtimer_start(&ts->sched_timer, tick,
+ HRTIMER_MODE_ABS_PINNED_HARD);
} else {
hrtimer_set_expires(&ts->sched_timer, tick);
tick_program_event(tick, 1);
* Recycle the hrtimer in ts, so we can share the
* hrtimer_forward with the highres code.
*/
- hrtimer_init(&ts->sched_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
+ hrtimer_init(&ts->sched_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_HARD);
/* Get the next period */
next = tick_init_jiffy_update();
/*
* Emulate tick processing via per-CPU hrtimers:
*/
- hrtimer_init(&ts->sched_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
+ hrtimer_init(&ts->sched_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_HARD);
ts->sched_timer.function = tick_sched_timer;
/* Get the next period (per-CPU) */
}
hrtimer_forward(&ts->sched_timer, now, tick_period);
- hrtimer_start_expires(&ts->sched_timer, HRTIMER_MODE_ABS_PINNED);
+ hrtimer_start_expires(&ts->sched_timer, HRTIMER_MODE_ABS_PINNED_HARD);
tick_nohz_activate(ts, NOHZ_MODE_HIGHRES);
}
#endif /* HIGH_RES_TIMERS */
struct timer_base {
raw_spinlock_t lock;
struct timer_list *running_timer;
+#ifdef CONFIG_PREEMPT_RT
+ spinlock_t expiry_lock;
+ atomic_t timer_waiters;
+#endif
unsigned long clk;
unsigned long next_expiry;
unsigned int cpu;
}
EXPORT_SYMBOL(try_to_del_timer_sync);
-#ifdef CONFIG_SMP
+#ifdef CONFIG_PREEMPT_RT
+static __init void timer_base_init_expiry_lock(struct timer_base *base)
+{
+ spin_lock_init(&base->expiry_lock);
+}
+
+static inline void timer_base_lock_expiry(struct timer_base *base)
+{
+ spin_lock(&base->expiry_lock);
+}
+
+static inline void timer_base_unlock_expiry(struct timer_base *base)
+{
+ spin_unlock(&base->expiry_lock);
+}
+
+/*
+ * The counterpart to del_timer_wait_running().
+ *
+ * If there is a waiter for base->expiry_lock, then it was waiting for the
+ * timer callback to finish. Drop expiry_lock and reaquire it. That allows
+ * the waiter to acquire the lock and make progress.
+ */
+static void timer_sync_wait_running(struct timer_base *base)
+{
+ if (atomic_read(&base->timer_waiters)) {
+ spin_unlock(&base->expiry_lock);
+ spin_lock(&base->expiry_lock);
+ }
+}
+
+/*
+ * This function is called on PREEMPT_RT kernels when the fast path
+ * deletion of a timer failed because the timer callback function was
+ * running.
+ *
+ * This prevents priority inversion, if the softirq thread on a remote CPU
+ * got preempted, and it prevents a life lock when the task which tries to
+ * delete a timer preempted the softirq thread running the timer callback
+ * function.
+ */
+static void del_timer_wait_running(struct timer_list *timer)
+{
+ u32 tf;
+
+ tf = READ_ONCE(timer->flags);
+ if (!(tf & TIMER_MIGRATING)) {
+ struct timer_base *base = get_timer_base(tf);
+
+ /*
+ * Mark the base as contended and grab the expiry lock,
+ * which is held by the softirq across the timer
+ * callback. Drop the lock immediately so the softirq can
+ * expire the next timer. In theory the timer could already
+ * be running again, but that's more than unlikely and just
+ * causes another wait loop.
+ */
+ atomic_inc(&base->timer_waiters);
+ spin_lock_bh(&base->expiry_lock);
+ atomic_dec(&base->timer_waiters);
+ spin_unlock_bh(&base->expiry_lock);
+ }
+}
+#else
+static inline void timer_base_init_expiry_lock(struct timer_base *base) { }
+static inline void timer_base_lock_expiry(struct timer_base *base) { }
+static inline void timer_base_unlock_expiry(struct timer_base *base) { }
+static inline void timer_sync_wait_running(struct timer_base *base) { }
+static inline void del_timer_wait_running(struct timer_list *timer) { }
+#endif
+
+#if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT_RT)
/**
* del_timer_sync - deactivate a timer and wait for the handler to finish.
* @timer: the timer to be deactivated
*/
int del_timer_sync(struct timer_list *timer)
{
+ int ret;
+
#ifdef CONFIG_LOCKDEP
unsigned long flags;
* could lead to deadlock.
*/
WARN_ON(in_irq() && !(timer->flags & TIMER_IRQSAFE));
- for (;;) {
- int ret = try_to_del_timer_sync(timer);
- if (ret >= 0)
- return ret;
- cpu_relax();
- }
+
+ do {
+ ret = try_to_del_timer_sync(timer);
+
+ if (unlikely(ret < 0)) {
+ del_timer_wait_running(timer);
+ cpu_relax();
+ }
+ } while (ret < 0);
+
+ return ret;
}
EXPORT_SYMBOL(del_timer_sync);
#endif
if (timer->flags & TIMER_IRQSAFE) {
raw_spin_unlock(&base->lock);
call_timer_fn(timer, fn, baseclk);
+ base->running_timer = NULL;
raw_spin_lock(&base->lock);
} else {
raw_spin_unlock_irq(&base->lock);
call_timer_fn(timer, fn, baseclk);
+ base->running_timer = NULL;
+ timer_sync_wait_running(base);
raw_spin_lock_irq(&base->lock);
}
}
#endif
scheduler_tick();
if (IS_ENABLED(CONFIG_POSIX_TIMERS))
- run_posix_cpu_timers(p);
+ run_posix_cpu_timers();
}
/**
if (!time_after_eq(jiffies, base->clk))
return;
+ timer_base_lock_expiry(base);
raw_spin_lock_irq(&base->lock);
/*
while (levels--)
expire_timers(base, heads + levels);
}
- base->running_timer = NULL;
raw_spin_unlock_irq(&base->lock);
+ timer_base_unlock_expiry(base);
}
/*
base->cpu = cpu;
raw_spin_lock_init(&base->lock);
base->clk = jiffies;
+ timer_base_init_expiry_lock(base);
}
}
* Start the timer first to prevent the NMI watchdog triggering
* before the timer has a chance to fire.
*/
- hrtimer_init(hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+ hrtimer_init(hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD);
hrtimer->function = watchdog_timer_fn;
hrtimer_start(hrtimer, ns_to_ktime(sample_period),
- HRTIMER_MODE_REL_PINNED);
+ HRTIMER_MODE_REL_PINNED_HARD);
/* Initialize timestamp */
__touch_watchdog();
*/
bool timerqueue_add(struct timerqueue_head *head, struct timerqueue_node *node)
{
- struct rb_node **p = &head->head.rb_node;
+ struct rb_node **p = &head->rb_root.rb_root.rb_node;
struct rb_node *parent = NULL;
- struct timerqueue_node *ptr;
+ struct timerqueue_node *ptr;
+ bool leftmost = true;
/* Make sure we don't add nodes that are already added */
WARN_ON_ONCE(!RB_EMPTY_NODE(&node->node));
while (*p) {
parent = *p;
ptr = rb_entry(parent, struct timerqueue_node, node);
- if (node->expires < ptr->expires)
+ if (node->expires < ptr->expires) {
p = &(*p)->rb_left;
- else
+ } else {
p = &(*p)->rb_right;
+ leftmost = false;
+ }
}
rb_link_node(&node->node, parent, p);
- rb_insert_color(&node->node, &head->head);
+ rb_insert_color_cached(&node->node, &head->rb_root, leftmost);
- if (!head->next || node->expires < head->next->expires) {
- head->next = node;
- return true;
- }
- return false;
+ return leftmost;
}
EXPORT_SYMBOL_GPL(timerqueue_add);
{
WARN_ON_ONCE(RB_EMPTY_NODE(&node->node));
- /* update next pointer */
- if (head->next == node) {
- struct rb_node *rbn = rb_next(&node->node);
-
- head->next = rb_entry_safe(rbn, struct timerqueue_node, node);
- }
- rb_erase(&node->node, &head->head);
+ rb_erase_cached(&node->node, &head->rb_root);
RB_CLEAR_NODE(&node->node);
- return head->next != NULL;
+
+ return !RB_EMPTY_ROOT(&head->rb_root.rb_root);
}
EXPORT_SYMBOL_GPL(timerqueue_del);
s64 remaining;
struct hrtimer_sleeper t;
- hrtimer_init_on_stack(&t.timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
+ hrtimer_init_sleeper_on_stack(&t, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
hrtimer_set_expires(&t.timer, spin_until);
remaining = ktime_to_ns(hrtimer_expires_remaining(&t.timer));
end_time = ktime_get();
} while (ktime_compare(end_time, spin_until) < 0);
} else {
- /* see do_nanosleep */
- hrtimer_init_sleeper(&t, current);
do {
set_current_state(TASK_INTERRUPTIBLE);
- hrtimer_start_expires(&t.timer, HRTIMER_MODE_ABS);
+ hrtimer_sleeper_start_expires(&t, HRTIMER_MODE_ABS);
if (likely(t.task))
schedule();
projects / linux-2.6-block.git / commitdiff