--- /dev/null
+
+Performance Counters for Linux
+------------------------------
+
+Performance counters are special hardware registers available on most modern
+CPUs. These registers count the number of certain types of hw events: such
+as instructions executed, cachemisses suffered, or branches mis-predicted -
+without slowing down the kernel or applications. These registers can also
+trigger interrupts when a threshold number of events have passed - and can
+thus be used to profile the code that runs on that CPU.
+
+The Linux Performance Counter subsystem provides an abstraction of these
+hardware capabilities. It provides per task and per CPU counters, counter
+groups, and it provides event capabilities on top of those.
+
+Performance counters are accessed via special file descriptors.
+There's one file descriptor per virtual counter used.
+
+The special file descriptor is opened via the perf_counter_open()
+system call:
+
+ int sys_perf_counter_open(struct perf_counter_hw_event *hw_event_uptr,
+ pid_t pid, int cpu, int group_fd);
+
+The syscall returns the new fd. The fd can be used via the normal
+VFS system calls: read() can be used to read the counter, fcntl()
+can be used to set the blocking mode, etc.
+
+Multiple counters can be kept open at a time, and the counters
+can be poll()ed.
+
+When creating a new counter fd, 'perf_counter_hw_event' is:
+
+/*
+ * Hardware event to monitor via a performance monitoring counter:
+ */
+struct perf_counter_hw_event {
+ s64 type;
+
+ u64 irq_period;
+ u32 record_type;
+
+ u32 disabled : 1, /* off by default */
+ nmi : 1, /* NMI sampling */
+ raw : 1, /* raw event type */
+ __reserved_1 : 29;
+
+ u64 __reserved_2;
+};
+
+/*
+ * Generalized performance counter event types, used by the hw_event.type
+ * parameter of the sys_perf_counter_open() syscall:
+ */
+enum hw_event_types {
+ /*
+ * Common hardware events, generalized by the kernel:
+ */
+ PERF_COUNT_CYCLES = 0,
+ PERF_COUNT_INSTRUCTIONS = 1,
+ PERF_COUNT_CACHE_REFERENCES = 2,
+ PERF_COUNT_CACHE_MISSES = 3,
+ PERF_COUNT_BRANCH_INSTRUCTIONS = 4,
+ PERF_COUNT_BRANCH_MISSES = 5,
+
+ /*
+ * Special "software" counters provided by the kernel, even if
+ * the hardware does not support performance counters. These
+ * counters measure various physical and sw events of the
+ * kernel (and allow the profiling of them as well):
+ */
+ PERF_COUNT_CPU_CLOCK = -1,
+ PERF_COUNT_TASK_CLOCK = -2,
+ /*
+ * Future software events:
+ */
+ /* PERF_COUNT_PAGE_FAULTS = -3,
+ PERF_COUNT_CONTEXT_SWITCHES = -4, */
+};
+
+These are standardized types of events that work uniformly on all CPUs
+that implements Performance Counters support under Linux. If a CPU is
+not able to count branch-misses, then the system call will return
+-EINVAL.
+
+More hw_event_types are supported as well, but they are CPU
+specific and are enumerated via /sys on a per CPU basis. Raw hw event
+types can be passed in under hw_event.type if hw_event.raw is 1.
+For example, to count "External bus cycles while bus lock signal asserted"
+events on Intel Core CPUs, pass in a 0x4064 event type value and set
+hw_event.raw to 1.
+
+'record_type' is the type of data that a read() will provide for the
+counter, and it can be one of:
+
+/*
+ * IRQ-notification data record type:
+ */
+enum perf_counter_record_type {
+ PERF_RECORD_SIMPLE = 0,
+ PERF_RECORD_IRQ = 1,
+ PERF_RECORD_GROUP = 2,
+};
+
+a "simple" counter is one that counts hardware events and allows
+them to be read out into a u64 count value. (read() returns 8 on
+a successful read of a simple counter.)
+
+An "irq" counter is one that will also provide an IRQ context information:
+the IP of the interrupted context. In this case read() will return
+the 8-byte counter value, plus the Instruction Pointer address of the
+interrupted context.
+
+The parameter 'hw_event_period' is the number of events before waking up
+a read() that is blocked on a counter fd. Zero value means a non-blocking
+counter.
+
+The 'pid' parameter allows the counter to be specific to a task:
+
+ pid == 0: if the pid parameter is zero, the counter is attached to the
+ current task.
+
+ pid > 0: the counter is attached to a specific task (if the current task
+ has sufficient privilege to do so)
+
+ pid < 0: all tasks are counted (per cpu counters)
+
+The 'cpu' parameter allows a counter to be made specific to a full
+CPU:
+
+ cpu >= 0: the counter is restricted to a specific CPU
+ cpu == -1: the counter counts on all CPUs
+
+(Note: the combination of 'pid == -1' and 'cpu == -1' is not valid.)
+
+A 'pid > 0' and 'cpu == -1' counter is a per task counter that counts
+events of that task and 'follows' that task to whatever CPU the task
+gets schedule to. Per task counters can be created by any user, for
+their own tasks.
+
+A 'pid == -1' and 'cpu == x' counter is a per CPU counter that counts
+all events on CPU-x. Per CPU counters need CAP_SYS_ADMIN privilege.
+
+Group counters are created by passing in a group_fd of another counter.
+Groups are scheduled at once and can be used with PERF_RECORD_GROUP
+to record multi-dimensional timestamps.
+
config X86_LOCAL_APIC
def_bool y
depends on X86_64 || (X86_32 && (X86_UP_APIC || (SMP && !X86_VOYAGER) || X86_GENERICARCH))
+ select HAVE_PERF_COUNTERS if (!M386 && !M486)
config X86_IO_APIC
def_bool y
.quad compat_sys_signalfd4
.quad sys_eventfd2
.quad sys_epoll_create1
- .quad sys_dup3 /* 330 */
+ .quad sys_dup3 /* 330 */
.quad sys_pipe2
.quad sys_inotify_init1
+ .quad sys_perf_counter_open
ia32_syscall_end:
#define smp_mb__before_atomic_inc() barrier()
#define smp_mb__after_atomic_inc() barrier()
+/* An 64bit atomic type */
+
+typedef struct {
+ unsigned long long counter;
+} atomic64_t;
+
+#define ATOMIC64_INIT(val) { (val) }
+
+/**
+ * atomic64_read - read atomic64 variable
+ * @v: pointer of type atomic64_t
+ *
+ * Atomically reads the value of @v.
+ * Doesn't imply a read memory barrier.
+ */
+#define __atomic64_read(ptr) ((ptr)->counter)
+
+static inline unsigned long long
+cmpxchg8b(unsigned long long *ptr, unsigned long long old, unsigned long long new)
+{
+ asm volatile(
+
+ LOCK_PREFIX "cmpxchg8b (%[ptr])\n"
+
+ : "=A" (old)
+
+ : [ptr] "D" (ptr),
+ "A" (old),
+ "b" (ll_low(new)),
+ "c" (ll_high(new))
+
+ : "memory");
+
+ return old;
+}
+
+static inline unsigned long long
+atomic64_cmpxchg(atomic64_t *ptr, unsigned long long old_val,
+ unsigned long long new_val)
+{
+ return cmpxchg8b(&ptr->counter, old_val, new_val);
+}
+
+/**
+ * atomic64_set - set atomic64 variable
+ * @ptr: pointer to type atomic64_t
+ * @new_val: value to assign
+ *
+ * Atomically sets the value of @ptr to @new_val.
+ */
+static inline void atomic64_set(atomic64_t *ptr, unsigned long long new_val)
+{
+ unsigned long long old_val;
+
+ do {
+ old_val = atomic_read(ptr);
+ } while (atomic64_cmpxchg(ptr, old_val, new_val) != old_val);
+}
+
+/**
+ * atomic64_read - read atomic64 variable
+ * @ptr: pointer to type atomic64_t
+ *
+ * Atomically reads the value of @ptr and returns it.
+ */
+static inline unsigned long long atomic64_read(atomic64_t *ptr)
+{
+ unsigned long long curr_val;
+
+ do {
+ curr_val = __atomic64_read(ptr);
+ } while (atomic64_cmpxchg(ptr, curr_val, curr_val) != curr_val);
+
+ return curr_val;
+}
+
+/**
+ * atomic64_add_return - add and return
+ * @delta: integer value to add
+ * @ptr: pointer to type atomic64_t
+ *
+ * Atomically adds @delta to @ptr and returns @delta + *@ptr
+ */
+static inline unsigned long long
+atomic64_add_return(unsigned long long delta, atomic64_t *ptr)
+{
+ unsigned long long old_val, new_val;
+
+ do {
+ old_val = atomic_read(ptr);
+ new_val = old_val + delta;
+
+ } while (atomic64_cmpxchg(ptr, old_val, new_val) != old_val);
+
+ return new_val;
+}
+
+static inline long atomic64_sub_return(unsigned long long delta, atomic64_t *ptr)
+{
+ return atomic64_add_return(-delta, ptr);
+}
+
+static inline long atomic64_inc_return(atomic64_t *ptr)
+{
+ return atomic64_add_return(1, ptr);
+}
+
+static inline long atomic64_dec_return(atomic64_t *ptr)
+{
+ return atomic64_sub_return(1, ptr);
+}
+
+/**
+ * atomic64_add - add integer to atomic64 variable
+ * @delta: integer value to add
+ * @ptr: pointer to type atomic64_t
+ *
+ * Atomically adds @delta to @ptr.
+ */
+static inline void atomic64_add(unsigned long long delta, atomic64_t *ptr)
+{
+ atomic64_add_return(delta, ptr);
+}
+
+/**
+ * atomic64_sub - subtract the atomic64 variable
+ * @delta: integer value to subtract
+ * @ptr: pointer to type atomic64_t
+ *
+ * Atomically subtracts @delta from @ptr.
+ */
+static inline void atomic64_sub(unsigned long long delta, atomic64_t *ptr)
+{
+ atomic64_add(-delta, ptr);
+}
+
+/**
+ * atomic64_sub_and_test - subtract value from variable and test result
+ * @delta: integer value to subtract
+ * @ptr: pointer to type atomic64_t
+ *
+ * Atomically subtracts @delta from @ptr and returns
+ * true if the result is zero, or false for all
+ * other cases.
+ */
+static inline int
+atomic64_sub_and_test(unsigned long long delta, atomic64_t *ptr)
+{
+ unsigned long long old_val = atomic64_sub_return(delta, ptr);
+
+ return old_val == 0;
+}
+
+/**
+ * atomic64_inc - increment atomic64 variable
+ * @ptr: pointer to type atomic64_t
+ *
+ * Atomically increments @ptr by 1.
+ */
+static inline void atomic64_inc(atomic64_t *ptr)
+{
+ atomic64_add(1, ptr);
+}
+
+/**
+ * atomic64_dec - decrement atomic64 variable
+ * @ptr: pointer to type atomic64_t
+ *
+ * Atomically decrements @ptr by 1.
+ */
+static inline void atomic64_dec(atomic64_t *ptr)
+{
+ atomic64_sub(1, ptr);
+}
+
+/**
+ * atomic64_dec_and_test - decrement and test
+ * @ptr: pointer to type atomic64_t
+ *
+ * Atomically decrements @ptr by 1 and
+ * returns true if the result is 0, or false for all other
+ * cases.
+ */
+static inline int atomic64_dec_and_test(atomic64_t *ptr)
+{
+ return atomic64_sub_and_test(1, ptr);
+}
+
+/**
+ * atomic64_inc_and_test - increment and test
+ * @ptr: pointer to type atomic64_t
+ *
+ * Atomically increments @ptr by 1
+ * and returns true if the result is zero, or false for all
+ * other cases.
+ */
+static inline int atomic64_inc_and_test(atomic64_t *ptr)
+{
+ return atomic64_sub_and_test(-1, ptr);
+}
+
+/**
+ * atomic64_add_negative - add and test if negative
+ * @delta: integer value to add
+ * @ptr: pointer to type atomic64_t
+ *
+ * Atomically adds @delta to @ptr and returns true
+ * if the result is negative, or false when
+ * result is greater than or equal to zero.
+ */
+static inline int
+atomic64_add_negative(unsigned long long delta, atomic64_t *ptr)
+{
+ long long old_val = atomic64_add_return(delta, ptr);
+
+ return old_val < 0;
+}
+
#include <asm-generic/atomic.h>
#endif /* _ASM_X86_ATOMIC_32_H */
unsigned long idle_timestamp;
unsigned int __nmi_count; /* arch dependent */
unsigned int apic_timer_irqs; /* arch dependent */
+ unsigned int apic_perf_irqs; /* arch dependent */
unsigned int irq0_irqs;
unsigned int irq_resched_count;
unsigned int irq_call_count;
/* Interrupt handlers registered during init_IRQ */
extern void apic_timer_interrupt(void);
extern void error_interrupt(void);
+extern void perf_counter_interrupt(void);
+
extern void spurious_interrupt(void);
extern void thermal_interrupt(void);
extern void reschedule_interrupt(void);
+++ /dev/null
-#ifndef _ASM_X86_INTEL_ARCH_PERFMON_H
-#define _ASM_X86_INTEL_ARCH_PERFMON_H
-
-#define MSR_ARCH_PERFMON_PERFCTR0 0xc1
-#define MSR_ARCH_PERFMON_PERFCTR1 0xc2
-
-#define MSR_ARCH_PERFMON_EVENTSEL0 0x186
-#define MSR_ARCH_PERFMON_EVENTSEL1 0x187
-
-#define ARCH_PERFMON_EVENTSEL0_ENABLE (1 << 22)
-#define ARCH_PERFMON_EVENTSEL_INT (1 << 20)
-#define ARCH_PERFMON_EVENTSEL_OS (1 << 17)
-#define ARCH_PERFMON_EVENTSEL_USR (1 << 16)
-
-#define ARCH_PERFMON_UNHALTED_CORE_CYCLES_SEL (0x3c)
-#define ARCH_PERFMON_UNHALTED_CORE_CYCLES_UMASK (0x00 << 8)
-#define ARCH_PERFMON_UNHALTED_CORE_CYCLES_INDEX (0)
-#define ARCH_PERFMON_UNHALTED_CORE_CYCLES_PRESENT \
- (1 << (ARCH_PERFMON_UNHALTED_CORE_CYCLES_INDEX))
-
-union cpuid10_eax {
- struct {
- unsigned int version_id:8;
- unsigned int num_counters:8;
- unsigned int bit_width:8;
- unsigned int mask_length:8;
- } split;
- unsigned int full;
-};
-
-#endif /* _ASM_X86_INTEL_ARCH_PERFMON_H */
*/
#define LOCAL_TIMER_VECTOR 0xef
+/*
+ * Performance monitoring interrupt vector:
+ */
+#define LOCAL_PERF_VECTOR 0xee
+
/*
* First APIC vector available to drivers: (vectors 0x30-0xee) we
* start at 0x31(0x41) to spread out vectors evenly between priority
* a much simpler SMP time architecture:
*/
#ifdef CONFIG_X86_LOCAL_APIC
+
BUILD_INTERRUPT(apic_timer_interrupt,LOCAL_TIMER_VECTOR)
BUILD_INTERRUPT(error_interrupt,ERROR_APIC_VECTOR)
BUILD_INTERRUPT(spurious_interrupt,SPURIOUS_APIC_VECTOR)
+#ifdef CONFIG_PERF_COUNTERS
+BUILD_INTERRUPT(perf_counter_interrupt, LOCAL_PERF_VECTOR)
+#endif
+
#ifdef CONFIG_X86_MCE_P4THERMAL
BUILD_INTERRUPT(thermal_interrupt,THERMAL_APIC_VECTOR)
#endif
short isidle;
struct mm_struct *active_mm;
unsigned apic_timer_irqs;
+ unsigned apic_perf_irqs;
unsigned irq0_irqs;
unsigned irq_resched_count;
unsigned irq_call_count;
--- /dev/null
+#ifndef _ASM_X86_PERF_COUNTER_H
+#define _ASM_X86_PERF_COUNTER_H
+
+/*
+ * Performance counter hw details:
+ */
+
+#define X86_PMC_MAX_GENERIC 8
+#define X86_PMC_MAX_FIXED 3
+
+#define X86_PMC_IDX_GENERIC 0
+#define X86_PMC_IDX_FIXED 32
+#define X86_PMC_IDX_MAX 64
+
+#define MSR_ARCH_PERFMON_PERFCTR0 0xc1
+#define MSR_ARCH_PERFMON_PERFCTR1 0xc2
+
+#define MSR_ARCH_PERFMON_EVENTSEL0 0x186
+#define MSR_ARCH_PERFMON_EVENTSEL1 0x187
+
+#define ARCH_PERFMON_EVENTSEL0_ENABLE (1 << 22)
+#define ARCH_PERFMON_EVENTSEL_INT (1 << 20)
+#define ARCH_PERFMON_EVENTSEL_OS (1 << 17)
+#define ARCH_PERFMON_EVENTSEL_USR (1 << 16)
+
+/*
+ * Includes eventsel and unit mask as well:
+ */
+#define ARCH_PERFMON_EVENT_MASK 0xffff
+
+#define ARCH_PERFMON_UNHALTED_CORE_CYCLES_SEL 0x3c
+#define ARCH_PERFMON_UNHALTED_CORE_CYCLES_UMASK (0x00 << 8)
+#define ARCH_PERFMON_UNHALTED_CORE_CYCLES_INDEX 0
+#define ARCH_PERFMON_UNHALTED_CORE_CYCLES_PRESENT \
+ (1 << (ARCH_PERFMON_UNHALTED_CORE_CYCLES_INDEX))
+
+#define ARCH_PERFMON_BRANCH_MISSES_RETIRED 6
+
+/*
+ * Intel "Architectural Performance Monitoring" CPUID
+ * detection/enumeration details:
+ */
+union cpuid10_eax {
+ struct {
+ unsigned int version_id:8;
+ unsigned int num_counters:8;
+ unsigned int bit_width:8;
+ unsigned int mask_length:8;
+ } split;
+ unsigned int full;
+};
+
+union cpuid10_edx {
+ struct {
+ unsigned int num_counters_fixed:4;
+ unsigned int reserved:28;
+ } split;
+ unsigned int full;
+};
+
+
+/*
+ * Fixed-purpose performance counters:
+ */
+
+/*
+ * All 3 fixed-mode PMCs are configured via this single MSR:
+ */
+#define MSR_ARCH_PERFMON_FIXED_CTR_CTRL 0x38d
+
+/*
+ * The counts are available in three separate MSRs:
+ */
+
+/* Instr_Retired.Any: */
+#define MSR_ARCH_PERFMON_FIXED_CTR0 0x309
+#define X86_PMC_IDX_FIXED_INSTRUCTIONS (X86_PMC_IDX_FIXED + 0)
+
+/* CPU_CLK_Unhalted.Core: */
+#define MSR_ARCH_PERFMON_FIXED_CTR1 0x30a
+#define X86_PMC_IDX_FIXED_CPU_CYCLES (X86_PMC_IDX_FIXED + 1)
+
+/* CPU_CLK_Unhalted.Ref: */
+#define MSR_ARCH_PERFMON_FIXED_CTR2 0x30b
+#define X86_PMC_IDX_FIXED_BUS_CYCLES (X86_PMC_IDX_FIXED + 2)
+
+#ifdef CONFIG_PERF_COUNTERS
+extern void init_hw_perf_counters(void);
+extern void perf_counters_lapic_init(int nmi);
+#else
+static inline void init_hw_perf_counters(void) { }
+static inline void perf_counters_lapic_init(int nmi) { }
+#endif
+
+#endif /* _ASM_X86_PERF_COUNTER_H */
#define TIF_SYSCALL_AUDIT 7 /* syscall auditing active */
#define TIF_SECCOMP 8 /* secure computing */
#define TIF_MCE_NOTIFY 10 /* notify userspace of an MCE */
+#define TIF_PERF_COUNTERS 11 /* notify perf counter work */
#define TIF_NOTSC 16 /* TSC is not accessible in userland */
#define TIF_IA32 17 /* 32bit process */
#define TIF_FORK 18 /* ret_from_fork */
#define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT)
#define _TIF_SECCOMP (1 << TIF_SECCOMP)
#define _TIF_MCE_NOTIFY (1 << TIF_MCE_NOTIFY)
+#define _TIF_PERF_COUNTERS (1 << TIF_PERF_COUNTERS)
#define _TIF_NOTSC (1 << TIF_NOTSC)
#define _TIF_IA32 (1 << TIF_IA32)
#define _TIF_FORK (1 << TIF_FORK)
/* Only used for 64 bit */
#define _TIF_DO_NOTIFY_MASK \
- (_TIF_SIGPENDING|_TIF_MCE_NOTIFY|_TIF_NOTIFY_RESUME)
+ (_TIF_SIGPENDING|_TIF_MCE_NOTIFY|_TIF_PERF_COUNTERS|_TIF_NOTIFY_RESUME)
/* flags to check in __switch_to() */
#define _TIF_WORK_CTXSW \
#define __NR_dup3 330
#define __NR_pipe2 331
#define __NR_inotify_init1 332
+#define __NR_perf_counter_open 333
#ifdef __KERNEL__
__SYSCALL(__NR_pipe2, sys_pipe2)
#define __NR_inotify_init1 294
__SYSCALL(__NR_inotify_init1, sys_inotify_init1)
-
+#define __NR_perf_counter_open 295
+__SYSCALL(__NR_perf_counter_open, sys_perf_counter_open)
#ifndef __NO_STUBS
#define __ARCH_WANT_OLD_READDIR
#include <linux/nmi.h>
#include <linux/timex.h>
+#include <asm/perf_counter.h>
#include <asm/atomic.h>
#include <asm/mtrr.h>
#include <asm/mpspec.h>
apic_write(APIC_ESR, 0);
}
#endif
+ perf_counters_lapic_init(0);
preempt_disable();
#
-# Makefile for x86-compatible CPU details and quirks
+# Makefile for x86-compatible CPU details, features and quirks
#
# Don't trace early stages of a secondary CPU boot
obj-$(CONFIG_CPU_SUP_TRANSMETA_32) += transmeta.o
obj-$(CONFIG_CPU_SUP_UMC_32) += umc.o
-obj-$(CONFIG_X86_MCE) += mcheck/
-obj-$(CONFIG_MTRR) += mtrr/
-obj-$(CONFIG_CPU_FREQ) += cpufreq/
+obj-$(CONFIG_PERF_COUNTERS) += perf_counter.o
-obj-$(CONFIG_X86_LOCAL_APIC) += perfctr-watchdog.o
+obj-$(CONFIG_X86_MCE) += mcheck/
+obj-$(CONFIG_MTRR) += mtrr/
+obj-$(CONFIG_CPU_FREQ) += cpufreq/
+
+obj-$(CONFIG_X86_LOCAL_APIC) += perfctr-watchdog.o
quiet_cmd_mkcapflags = MKCAP $@
cmd_mkcapflags = $(PERL) $(srctree)/$(src)/mkcapflags.pl $< $@
#include <asm/mmu_context.h>
#include <asm/mtrr.h>
#include <asm/mce.h>
+#include <asm/perf_counter.h>
#include <asm/pat.h>
#include <asm/asm.h>
#include <asm/numa.h>
#else
vgetcpu_set_mode();
#endif
+ init_hw_perf_counters();
}
void __cpuinit identify_secondary_cpu(struct cpuinfo_x86 *c)
--- /dev/null
+/*
+ * Performance counter x86 architecture code
+ *
+ * Copyright(C) 2008 Thomas Gleixner <tglx@linutronix.de>
+ * Copyright(C) 2008 Red Hat, Inc., Ingo Molnar
+ *
+ * For licencing details see kernel-base/COPYING
+ */
+
+#include <linux/perf_counter.h>
+#include <linux/capability.h>
+#include <linux/notifier.h>
+#include <linux/hardirq.h>
+#include <linux/kprobes.h>
+#include <linux/module.h>
+#include <linux/kdebug.h>
+#include <linux/sched.h>
+
+#include <asm/perf_counter.h>
+#include <asm/apic.h>
+
+static bool perf_counters_initialized __read_mostly;
+
+/*
+ * Number of (generic) HW counters:
+ */
+static int nr_counters_generic __read_mostly;
+static u64 perf_counter_mask __read_mostly;
+static u64 counter_value_mask __read_mostly;
+
+static int nr_counters_fixed __read_mostly;
+
+struct cpu_hw_counters {
+ struct perf_counter *counters[X86_PMC_IDX_MAX];
+ unsigned long used[BITS_TO_LONGS(X86_PMC_IDX_MAX)];
+};
+
+/*
+ * Intel PerfMon v3. Used on Core2 and later.
+ */
+static DEFINE_PER_CPU(struct cpu_hw_counters, cpu_hw_counters);
+
+static const int intel_perfmon_event_map[] =
+{
+ [PERF_COUNT_CPU_CYCLES] = 0x003c,
+ [PERF_COUNT_INSTRUCTIONS] = 0x00c0,
+ [PERF_COUNT_CACHE_REFERENCES] = 0x4f2e,
+ [PERF_COUNT_CACHE_MISSES] = 0x412e,
+ [PERF_COUNT_BRANCH_INSTRUCTIONS] = 0x00c4,
+ [PERF_COUNT_BRANCH_MISSES] = 0x00c5,
+ [PERF_COUNT_BUS_CYCLES] = 0x013c,
+};
+
+static const int max_intel_perfmon_events = ARRAY_SIZE(intel_perfmon_event_map);
+
+/*
+ * Propagate counter elapsed time into the generic counter.
+ * Can only be executed on the CPU where the counter is active.
+ * Returns the delta events processed.
+ */
+static void
+x86_perf_counter_update(struct perf_counter *counter,
+ struct hw_perf_counter *hwc, int idx)
+{
+ u64 prev_raw_count, new_raw_count, delta;
+
+ /*
+ * Careful: an NMI might modify the previous counter value.
+ *
+ * Our tactic to handle this is to first atomically read and
+ * exchange a new raw count - then add that new-prev delta
+ * count to the generic counter atomically:
+ */
+again:
+ prev_raw_count = atomic64_read(&hwc->prev_count);
+ rdmsrl(hwc->counter_base + idx, new_raw_count);
+
+ if (atomic64_cmpxchg(&hwc->prev_count, prev_raw_count,
+ new_raw_count) != prev_raw_count)
+ goto again;
+
+ /*
+ * Now we have the new raw value and have updated the prev
+ * timestamp already. We can now calculate the elapsed delta
+ * (counter-)time and add that to the generic counter.
+ *
+ * Careful, not all hw sign-extends above the physical width
+ * of the count, so we do that by clipping the delta to 32 bits:
+ */
+ delta = (u64)(u32)((s32)new_raw_count - (s32)prev_raw_count);
+
+ atomic64_add(delta, &counter->count);
+ atomic64_sub(delta, &hwc->period_left);
+}
+
+/*
+ * Setup the hardware configuration for a given hw_event_type
+ */
+static int __hw_perf_counter_init(struct perf_counter *counter)
+{
+ struct perf_counter_hw_event *hw_event = &counter->hw_event;
+ struct hw_perf_counter *hwc = &counter->hw;
+
+ if (unlikely(!perf_counters_initialized))
+ return -EINVAL;
+
+ /*
+ * Count user events, and generate PMC IRQs:
+ * (keep 'enabled' bit clear for now)
+ */
+ hwc->config = ARCH_PERFMON_EVENTSEL_USR | ARCH_PERFMON_EVENTSEL_INT;
+
+ /*
+ * If privileged enough, count OS events too, and allow
+ * NMI events as well:
+ */
+ hwc->nmi = 0;
+ if (capable(CAP_SYS_ADMIN)) {
+ hwc->config |= ARCH_PERFMON_EVENTSEL_OS;
+ if (hw_event->nmi)
+ hwc->nmi = 1;
+ }
+
+ hwc->irq_period = hw_event->irq_period;
+ /*
+ * Intel PMCs cannot be accessed sanely above 32 bit width,
+ * so we install an artificial 1<<31 period regardless of
+ * the generic counter period:
+ */
+ if ((s64)hwc->irq_period <= 0 || hwc->irq_period > 0x7FFFFFFF)
+ hwc->irq_period = 0x7FFFFFFF;
+
+ atomic64_set(&hwc->period_left, hwc->irq_period);
+
+ /*
+ * Raw event type provide the config in the event structure
+ */
+ if (hw_event->raw) {
+ hwc->config |= hw_event->type;
+ } else {
+ if (hw_event->type >= max_intel_perfmon_events)
+ return -EINVAL;
+ /*
+ * The generic map:
+ */
+ hwc->config |= intel_perfmon_event_map[hw_event->type];
+ }
+ counter->wakeup_pending = 0;
+
+ return 0;
+}
+
+u64 hw_perf_save_disable(void)
+{
+ u64 ctrl;
+
+ if (unlikely(!perf_counters_initialized))
+ return 0;
+
+ rdmsrl(MSR_CORE_PERF_GLOBAL_CTRL, ctrl);
+ wrmsrl(MSR_CORE_PERF_GLOBAL_CTRL, 0);
+
+ return ctrl;
+}
+EXPORT_SYMBOL_GPL(hw_perf_save_disable);
+
+void hw_perf_restore(u64 ctrl)
+{
+ if (unlikely(!perf_counters_initialized))
+ return;
+
+ wrmsrl(MSR_CORE_PERF_GLOBAL_CTRL, ctrl);
+}
+EXPORT_SYMBOL_GPL(hw_perf_restore);
+
+static inline void
+__pmc_fixed_disable(struct perf_counter *counter,
+ struct hw_perf_counter *hwc, unsigned int __idx)
+{
+ int idx = __idx - X86_PMC_IDX_FIXED;
+ u64 ctrl_val, mask;
+ int err;
+
+ mask = 0xfULL << (idx * 4);
+
+ rdmsrl(hwc->config_base, ctrl_val);
+ ctrl_val &= ~mask;
+ err = checking_wrmsrl(hwc->config_base, ctrl_val);
+}
+
+static inline void
+__pmc_generic_disable(struct perf_counter *counter,
+ struct hw_perf_counter *hwc, unsigned int idx)
+{
+ if (unlikely(hwc->config_base == MSR_ARCH_PERFMON_FIXED_CTR_CTRL))
+ __pmc_fixed_disable(counter, hwc, idx);
+ else
+ wrmsr_safe(hwc->config_base + idx, hwc->config, 0);
+}
+
+static DEFINE_PER_CPU(u64, prev_left[X86_PMC_IDX_MAX]);
+
+/*
+ * Set the next IRQ period, based on the hwc->period_left value.
+ * To be called with the counter disabled in hw:
+ */
+static void
+__hw_perf_counter_set_period(struct perf_counter *counter,
+ struct hw_perf_counter *hwc, int idx)
+{
+ s64 left = atomic64_read(&hwc->period_left);
+ s32 period = hwc->irq_period;
+ int err;
+
+ /*
+ * If we are way outside a reasoable range then just skip forward:
+ */
+ if (unlikely(left <= -period)) {
+ left = period;
+ atomic64_set(&hwc->period_left, left);
+ }
+
+ if (unlikely(left <= 0)) {
+ left += period;
+ atomic64_set(&hwc->period_left, left);
+ }
+
+ per_cpu(prev_left[idx], smp_processor_id()) = left;
+
+ /*
+ * The hw counter starts counting from this counter offset,
+ * mark it to be able to extra future deltas:
+ */
+ atomic64_set(&hwc->prev_count, (u64)-left);
+
+ err = checking_wrmsrl(hwc->counter_base + idx,
+ (u64)(-left) & counter_value_mask);
+}
+
+static inline void
+__pmc_fixed_enable(struct perf_counter *counter,
+ struct hw_perf_counter *hwc, unsigned int __idx)
+{
+ int idx = __idx - X86_PMC_IDX_FIXED;
+ u64 ctrl_val, bits, mask;
+ int err;
+
+ /*
+ * Enable IRQ generation (0x8) and ring-3 counting (0x2),
+ * and enable ring-0 counting if allowed:
+ */
+ bits = 0x8ULL | 0x2ULL;
+ if (hwc->config & ARCH_PERFMON_EVENTSEL_OS)
+ bits |= 0x1;
+ bits <<= (idx * 4);
+ mask = 0xfULL << (idx * 4);
+
+ rdmsrl(hwc->config_base, ctrl_val);
+ ctrl_val &= ~mask;
+ ctrl_val |= bits;
+ err = checking_wrmsrl(hwc->config_base, ctrl_val);
+}
+
+static void
+__pmc_generic_enable(struct perf_counter *counter,
+ struct hw_perf_counter *hwc, int idx)
+{
+ if (unlikely(hwc->config_base == MSR_ARCH_PERFMON_FIXED_CTR_CTRL))
+ __pmc_fixed_enable(counter, hwc, idx);
+ else
+ wrmsr(hwc->config_base + idx,
+ hwc->config | ARCH_PERFMON_EVENTSEL0_ENABLE, 0);
+}
+
+static int
+fixed_mode_idx(struct perf_counter *counter, struct hw_perf_counter *hwc)
+{
+ unsigned int event;
+
+ if (unlikely(hwc->nmi))
+ return -1;
+
+ event = hwc->config & ARCH_PERFMON_EVENT_MASK;
+
+ if (unlikely(event == intel_perfmon_event_map[PERF_COUNT_INSTRUCTIONS]))
+ return X86_PMC_IDX_FIXED_INSTRUCTIONS;
+ if (unlikely(event == intel_perfmon_event_map[PERF_COUNT_CPU_CYCLES]))
+ return X86_PMC_IDX_FIXED_CPU_CYCLES;
+ if (unlikely(event == intel_perfmon_event_map[PERF_COUNT_BUS_CYCLES]))
+ return X86_PMC_IDX_FIXED_BUS_CYCLES;
+
+ return -1;
+}
+
+/*
+ * Find a PMC slot for the freshly enabled / scheduled in counter:
+ */
+static int pmc_generic_enable(struct perf_counter *counter)
+{
+ struct cpu_hw_counters *cpuc = &__get_cpu_var(cpu_hw_counters);
+ struct hw_perf_counter *hwc = &counter->hw;
+ int idx;
+
+ idx = fixed_mode_idx(counter, hwc);
+ if (idx >= 0) {
+ /*
+ * Try to get the fixed counter, if that is already taken
+ * then try to get a generic counter:
+ */
+ if (test_and_set_bit(idx, cpuc->used))
+ goto try_generic;
+
+ hwc->config_base = MSR_ARCH_PERFMON_FIXED_CTR_CTRL;
+ /*
+ * We set it so that counter_base + idx in wrmsr/rdmsr maps to
+ * MSR_ARCH_PERFMON_FIXED_CTR0 ... CTR2:
+ */
+ hwc->counter_base =
+ MSR_ARCH_PERFMON_FIXED_CTR0 - X86_PMC_IDX_FIXED;
+ hwc->idx = idx;
+ } else {
+ idx = hwc->idx;
+ /* Try to get the previous generic counter again */
+ if (test_and_set_bit(idx, cpuc->used)) {
+try_generic:
+ idx = find_first_zero_bit(cpuc->used, nr_counters_generic);
+ if (idx == nr_counters_generic)
+ return -EAGAIN;
+
+ set_bit(idx, cpuc->used);
+ hwc->idx = idx;
+ }
+ hwc->config_base = MSR_ARCH_PERFMON_EVENTSEL0;
+ hwc->counter_base = MSR_ARCH_PERFMON_PERFCTR0;
+ }
+
+ perf_counters_lapic_init(hwc->nmi);
+
+ __pmc_generic_disable(counter, hwc, idx);
+
+ cpuc->counters[idx] = counter;
+ /*
+ * Make it visible before enabling the hw:
+ */
+ smp_wmb();
+
+ __hw_perf_counter_set_period(counter, hwc, idx);
+ __pmc_generic_enable(counter, hwc, idx);
+
+ return 0;
+}
+
+void perf_counter_print_debug(void)
+{
+ u64 ctrl, status, overflow, pmc_ctrl, pmc_count, prev_left, fixed;
+ struct cpu_hw_counters *cpuc;
+ int cpu, idx;
+
+ if (!nr_counters_generic)
+ return;
+
+ local_irq_disable();
+
+ cpu = smp_processor_id();
+ cpuc = &per_cpu(cpu_hw_counters, cpu);
+
+ rdmsrl(MSR_CORE_PERF_GLOBAL_CTRL, ctrl);
+ rdmsrl(MSR_CORE_PERF_GLOBAL_STATUS, status);
+ rdmsrl(MSR_CORE_PERF_GLOBAL_OVF_CTRL, overflow);
+ rdmsrl(MSR_ARCH_PERFMON_FIXED_CTR_CTRL, fixed);
+
+ printk(KERN_INFO "\n");
+ printk(KERN_INFO "CPU#%d: ctrl: %016llx\n", cpu, ctrl);
+ printk(KERN_INFO "CPU#%d: status: %016llx\n", cpu, status);
+ printk(KERN_INFO "CPU#%d: overflow: %016llx\n", cpu, overflow);
+ printk(KERN_INFO "CPU#%d: fixed: %016llx\n", cpu, fixed);
+ printk(KERN_INFO "CPU#%d: used: %016llx\n", cpu, *(u64 *)cpuc->used);
+
+ for (idx = 0; idx < nr_counters_generic; idx++) {
+ rdmsrl(MSR_ARCH_PERFMON_EVENTSEL0 + idx, pmc_ctrl);
+ rdmsrl(MSR_ARCH_PERFMON_PERFCTR0 + idx, pmc_count);
+
+ prev_left = per_cpu(prev_left[idx], cpu);
+
+ printk(KERN_INFO "CPU#%d: gen-PMC%d ctrl: %016llx\n",
+ cpu, idx, pmc_ctrl);
+ printk(KERN_INFO "CPU#%d: gen-PMC%d count: %016llx\n",
+ cpu, idx, pmc_count);
+ printk(KERN_INFO "CPU#%d: gen-PMC%d left: %016llx\n",
+ cpu, idx, prev_left);
+ }
+ for (idx = 0; idx < nr_counters_fixed; idx++) {
+ rdmsrl(MSR_ARCH_PERFMON_FIXED_CTR0 + idx, pmc_count);
+
+ printk(KERN_INFO "CPU#%d: fixed-PMC%d count: %016llx\n",
+ cpu, idx, pmc_count);
+ }
+ local_irq_enable();
+}
+
+static void pmc_generic_disable(struct perf_counter *counter)
+{
+ struct cpu_hw_counters *cpuc = &__get_cpu_var(cpu_hw_counters);
+ struct hw_perf_counter *hwc = &counter->hw;
+ unsigned int idx = hwc->idx;
+
+ __pmc_generic_disable(counter, hwc, idx);
+
+ clear_bit(idx, cpuc->used);
+ cpuc->counters[idx] = NULL;
+ /*
+ * Make sure the cleared pointer becomes visible before we
+ * (potentially) free the counter:
+ */
+ smp_wmb();
+
+ /*
+ * Drain the remaining delta count out of a counter
+ * that we are disabling:
+ */
+ x86_perf_counter_update(counter, hwc, idx);
+}
+
+static void perf_store_irq_data(struct perf_counter *counter, u64 data)
+{
+ struct perf_data *irqdata = counter->irqdata;
+
+ if (irqdata->len > PERF_DATA_BUFLEN - sizeof(u64)) {
+ irqdata->overrun++;
+ } else {
+ u64 *p = (u64 *) &irqdata->data[irqdata->len];
+
+ *p = data;
+ irqdata->len += sizeof(u64);
+ }
+}
+
+/*
+ * Save and restart an expired counter. Called by NMI contexts,
+ * so it has to be careful about preempting normal counter ops:
+ */
+static void perf_save_and_restart(struct perf_counter *counter)
+{
+ struct hw_perf_counter *hwc = &counter->hw;
+ int idx = hwc->idx;
+
+ x86_perf_counter_update(counter, hwc, idx);
+ __hw_perf_counter_set_period(counter, hwc, idx);
+
+ if (counter->state == PERF_COUNTER_STATE_ACTIVE)
+ __pmc_generic_enable(counter, hwc, idx);
+}
+
+static void
+perf_handle_group(struct perf_counter *sibling, u64 *status, u64 *overflown)
+{
+ struct perf_counter *counter, *group_leader = sibling->group_leader;
+
+ /*
+ * Store sibling timestamps (if any):
+ */
+ list_for_each_entry(counter, &group_leader->sibling_list, list_entry) {
+
+ x86_perf_counter_update(counter, &counter->hw, counter->hw.idx);
+ perf_store_irq_data(sibling, counter->hw_event.type);
+ perf_store_irq_data(sibling, atomic64_read(&counter->count));
+ }
+}
+
+/*
+ * This handler is triggered by the local APIC, so the APIC IRQ handling
+ * rules apply:
+ */
+static void __smp_perf_counter_interrupt(struct pt_regs *regs, int nmi)
+{
+ int bit, cpu = smp_processor_id();
+ u64 ack, status, saved_global;
+ struct cpu_hw_counters *cpuc;
+
+ rdmsrl(MSR_CORE_PERF_GLOBAL_CTRL, saved_global);
+
+ /* Disable counters globally */
+ wrmsrl(MSR_CORE_PERF_GLOBAL_CTRL, 0);
+ ack_APIC_irq();
+
+ cpuc = &per_cpu(cpu_hw_counters, cpu);
+
+ rdmsrl(MSR_CORE_PERF_GLOBAL_STATUS, status);
+ if (!status)
+ goto out;
+
+again:
+ ack = status;
+ for_each_bit(bit, (unsigned long *)&status, X86_PMC_IDX_MAX) {
+ struct perf_counter *counter = cpuc->counters[bit];
+
+ clear_bit(bit, (unsigned long *) &status);
+ if (!counter)
+ continue;
+
+ perf_save_and_restart(counter);
+
+ switch (counter->hw_event.record_type) {
+ case PERF_RECORD_SIMPLE:
+ continue;
+ case PERF_RECORD_IRQ:
+ perf_store_irq_data(counter, instruction_pointer(regs));
+ break;
+ case PERF_RECORD_GROUP:
+ perf_handle_group(counter, &status, &ack);
+ break;
+ }
+ /*
+ * From NMI context we cannot call into the scheduler to
+ * do a task wakeup - but we mark these generic as
+ * wakeup_pending and initate a wakeup callback:
+ */
+ if (nmi) {
+ counter->wakeup_pending = 1;
+ set_tsk_thread_flag(current, TIF_PERF_COUNTERS);
+ } else {
+ wake_up(&counter->waitq);
+ }
+ }
+
+ wrmsrl(MSR_CORE_PERF_GLOBAL_OVF_CTRL, ack);
+
+ /*
+ * Repeat if there is more work to be done:
+ */
+ rdmsrl(MSR_CORE_PERF_GLOBAL_STATUS, status);
+ if (status)
+ goto again;
+out:
+ /*
+ * Restore - do not reenable when global enable is off:
+ */
+ wrmsrl(MSR_CORE_PERF_GLOBAL_CTRL, saved_global);
+}
+
+void smp_perf_counter_interrupt(struct pt_regs *regs)
+{
+ irq_enter();
+ inc_irq_stat(apic_perf_irqs);
+ apic_write(APIC_LVTPC, LOCAL_PERF_VECTOR);
+ __smp_perf_counter_interrupt(regs, 0);
+
+ irq_exit();
+}
+
+/*
+ * This handler is triggered by NMI contexts:
+ */
+void perf_counter_notify(struct pt_regs *regs)
+{
+ struct cpu_hw_counters *cpuc;
+ unsigned long flags;
+ int bit, cpu;
+
+ local_irq_save(flags);
+ cpu = smp_processor_id();
+ cpuc = &per_cpu(cpu_hw_counters, cpu);
+
+ for_each_bit(bit, cpuc->used, X86_PMC_IDX_MAX) {
+ struct perf_counter *counter = cpuc->counters[bit];
+
+ if (!counter)
+ continue;
+
+ if (counter->wakeup_pending) {
+ counter->wakeup_pending = 0;
+ wake_up(&counter->waitq);
+ }
+ }
+
+ local_irq_restore(flags);
+}
+
+void __cpuinit perf_counters_lapic_init(int nmi)
+{
+ u32 apic_val;
+
+ if (!perf_counters_initialized)
+ return;
+ /*
+ * Enable the performance counter vector in the APIC LVT:
+ */
+ apic_val = apic_read(APIC_LVTERR);
+
+ apic_write(APIC_LVTERR, apic_val | APIC_LVT_MASKED);
+ if (nmi)
+ apic_write(APIC_LVTPC, APIC_DM_NMI);
+ else
+ apic_write(APIC_LVTPC, LOCAL_PERF_VECTOR);
+ apic_write(APIC_LVTERR, apic_val);
+}
+
+static int __kprobes
+perf_counter_nmi_handler(struct notifier_block *self,
+ unsigned long cmd, void *__args)
+{
+ struct die_args *args = __args;
+ struct pt_regs *regs;
+
+ if (likely(cmd != DIE_NMI_IPI))
+ return NOTIFY_DONE;
+
+ regs = args->regs;
+
+ apic_write(APIC_LVTPC, APIC_DM_NMI);
+ __smp_perf_counter_interrupt(regs, 1);
+
+ return NOTIFY_STOP;
+}
+
+static __read_mostly struct notifier_block perf_counter_nmi_notifier = {
+ .notifier_call = perf_counter_nmi_handler
+};
+
+void __init init_hw_perf_counters(void)
+{
+ union cpuid10_eax eax;
+ unsigned int ebx;
+ unsigned int unused;
+ union cpuid10_edx edx;
+
+ if (!cpu_has(&boot_cpu_data, X86_FEATURE_ARCH_PERFMON))
+ return;
+
+ /*
+ * Check whether the Architectural PerfMon supports
+ * Branch Misses Retired Event or not.
+ */
+ cpuid(10, &eax.full, &ebx, &unused, &edx.full);
+ if (eax.split.mask_length <= ARCH_PERFMON_BRANCH_MISSES_RETIRED)
+ return;
+
+ printk(KERN_INFO "Intel Performance Monitoring support detected.\n");
+
+ printk(KERN_INFO "... version: %d\n", eax.split.version_id);
+ printk(KERN_INFO "... num counters: %d\n", eax.split.num_counters);
+ nr_counters_generic = eax.split.num_counters;
+ if (nr_counters_generic > X86_PMC_MAX_GENERIC) {
+ nr_counters_generic = X86_PMC_MAX_GENERIC;
+ WARN(1, KERN_ERR "hw perf counters %d > max(%d), clipping!",
+ nr_counters_generic, X86_PMC_MAX_GENERIC);
+ }
+ perf_counter_mask = (1 << nr_counters_generic) - 1;
+ perf_max_counters = nr_counters_generic;
+
+ printk(KERN_INFO "... bit width: %d\n", eax.split.bit_width);
+ counter_value_mask = (1ULL << eax.split.bit_width) - 1;
+ printk(KERN_INFO "... value mask: %016Lx\n", counter_value_mask);
+
+ printk(KERN_INFO "... mask length: %d\n", eax.split.mask_length);
+
+ nr_counters_fixed = edx.split.num_counters_fixed;
+ if (nr_counters_fixed > X86_PMC_MAX_FIXED) {
+ nr_counters_fixed = X86_PMC_MAX_FIXED;
+ WARN(1, KERN_ERR "hw perf counters fixed %d > max(%d), clipping!",
+ nr_counters_fixed, X86_PMC_MAX_FIXED);
+ }
+ printk(KERN_INFO "... fixed counters: %d\n", nr_counters_fixed);
+
+ perf_counter_mask |= ((1LL << nr_counters_fixed)-1) << X86_PMC_IDX_FIXED;
+
+ printk(KERN_INFO "... counter mask: %016Lx\n", perf_counter_mask);
+ perf_counters_initialized = true;
+
+ perf_counters_lapic_init(0);
+ register_die_notifier(&perf_counter_nmi_notifier);
+}
+
+static void pmc_generic_read(struct perf_counter *counter)
+{
+ x86_perf_counter_update(counter, &counter->hw, counter->hw.idx);
+}
+
+static const struct hw_perf_counter_ops x86_perf_counter_ops = {
+ .enable = pmc_generic_enable,
+ .disable = pmc_generic_disable,
+ .read = pmc_generic_read,
+};
+
+const struct hw_perf_counter_ops *
+hw_perf_counter_init(struct perf_counter *counter)
+{
+ int err;
+
+ err = __hw_perf_counter_init(counter);
+ if (err)
+ return NULL;
+
+ return &x86_perf_counter_ops;
+}
#include <linux/kprobes.h>
#include <asm/apic.h>
-#include <asm/intel_arch_perfmon.h>
+#include <asm/perf_counter.h>
struct nmi_watchdog_ctlblk {
unsigned int cccr_msr;
apicinterrupt SPURIOUS_APIC_VECTOR \
spurious_interrupt smp_spurious_interrupt
+#ifdef CONFIG_PERF_COUNTERS
+apicinterrupt LOCAL_PERF_VECTOR \
+ perf_counter_interrupt smp_perf_counter_interrupt
+#endif
+
/*
* Exception entry points.
*/
for_each_online_cpu(j)
seq_printf(p, "%10u ", irq_stats(j)->apic_timer_irqs);
seq_printf(p, " Local timer interrupts\n");
+ seq_printf(p, "CNT: ");
+ for_each_online_cpu(j)
+ seq_printf(p, "%10u ", irq_stats(j)->apic_perf_irqs);
+ seq_printf(p, " Performance counter interrupts\n");
#endif
#ifdef CONFIG_SMP
seq_printf(p, "RES: ");
#ifdef CONFIG_X86_LOCAL_APIC
sum += irq_stats(cpu)->apic_timer_irqs;
+ sum += irq_stats(cpu)->apic_perf_irqs;
#endif
#ifdef CONFIG_SMP
sum += irq_stats(cpu)->irq_resched_count;
/* IPI vectors for APIC spurious and error interrupts */
alloc_intr_gate(SPURIOUS_APIC_VECTOR, spurious_interrupt);
alloc_intr_gate(ERROR_APIC_VECTOR, error_interrupt);
+# ifdef CONFIG_PERF_COUNTERS
+ alloc_intr_gate(LOCAL_PERF_VECTOR, perf_counter_interrupt);
+# endif
#endif
#if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86_MCE_P4THERMAL)
/* IPI vectors for APIC spurious and error interrupts */
alloc_intr_gate(SPURIOUS_APIC_VECTOR, spurious_interrupt);
alloc_intr_gate(ERROR_APIC_VECTOR, error_interrupt);
+
+ /* Performance monitoring interrupt: */
+#ifdef CONFIG_PERF_COUNTERS
+ alloc_intr_gate(LOCAL_PERF_VECTOR, perf_counter_interrupt);
+#endif
}
void __init native_init_IRQ(void)
* 2000-06-20 Pentium III FXSR, SSE support by Gareth Hughes
* 2000-2002 x86-64 support by Andi Kleen
*/
-
+#include <linux/perf_counter.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/smp.h>
tracehook_notify_resume(regs);
}
+ if (thread_info_flags & _TIF_PERF_COUNTERS) {
+ clear_thread_flag(TIF_PERF_COUNTERS);
+ perf_counter_notify(regs);
+ }
+
#ifdef CONFIG_X86_32
clear_thread_flag(TIF_IRET);
#endif /* CONFIG_X86_32 */
.long sys_dup3 /* 330 */
.long sys_pipe2
.long sys_inotify_init1
+ .long sys_perf_counter_open
#include <asm/msr.h>
#include <asm/apic.h>
#include <asm/nmi.h>
-#include <asm/intel_arch_perfmon.h>
+#include <asm/perf_counter.h>
#include "op_x86_model.h"
#include "op_counter.h"
/* Common C-state entry for C2, C3, .. */
static void acpi_cstate_enter(struct acpi_processor_cx *cstate)
{
+ u64 perf_flags;
+
/* Don't trace irqs off for idle */
stop_critical_timings();
+ perf_flags = hw_perf_save_disable();
if (cstate->entry_method == ACPI_CSTATE_FFH) {
/* Call into architectural FFH based C-state */
acpi_processor_ffh_cstate_enter(cstate);
gets asserted in time to freeze execution properly. */
unused = inl(acpi_gbl_FADT.xpm_timer_block.address);
}
+ hw_perf_restore(perf_flags);
start_critical_timings();
}
#endif /* !CONFIG_CPU_IDLE */
*/
static inline void acpi_idle_do_entry(struct acpi_processor_cx *cx)
{
+ u64 pctrl;
+
/* Don't trace irqs off for idle */
stop_critical_timings();
+ pctrl = hw_perf_save_disable();
if (cx->entry_method == ACPI_CSTATE_FFH) {
/* Call into architectural FFH based C-state */
acpi_processor_ffh_cstate_enter(cx);
gets asserted in time to freeze execution properly. */
unused = inl(acpi_gbl_FADT.xpm_timer_block.address);
}
+ hw_perf_restore(pctrl);
start_critical_timings();
}
#include <linux/kbd_kern.h>
#include <linux/proc_fs.h>
#include <linux/quotaops.h>
+#include <linux/perf_counter.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/suspend.h>
struct pt_regs *regs = get_irq_regs();
if (regs)
show_regs(regs);
+ perf_counter_print_debug();
}
static struct sysrq_key_op sysrq_showregs_op = {
.handler = sysrq_handle_showregs,
#include <linux/string.h>
#include <linux/init.h>
#include <linux/pagemap.h>
+#include <linux/perf_counter.h>
#include <linux/highmem.h>
#include <linux/spinlock.h>
#include <linux/key.h>
current->personality &= ~bprm->per_clear;
+ /*
+ * Flush performance counters when crossing a
+ * security domain:
+ */
+ if (!get_dumpable(current->mm))
+ perf_counter_exit_task(current);
+
/* An exec changes our domain. We are no longer part of the thread
group */
extern struct cred init_cred;
+#ifdef CONFIG_PERF_COUNTERS
+# define INIT_PERF_COUNTERS(tsk) \
+ .perf_counter_ctx.counter_list = \
+ LIST_HEAD_INIT(tsk.perf_counter_ctx.counter_list), \
+ .perf_counter_ctx.lock = \
+ __SPIN_LOCK_UNLOCKED(tsk.perf_counter_ctx.lock),
+#else
+# define INIT_PERF_COUNTERS(tsk)
+#endif
+
/*
* INIT_TASK is used to set up the first task table, touch at
* your own risk!. Base=0, limit=0x1fffff (=2MB)
INIT_IDS \
INIT_TRACE_IRQFLAGS \
INIT_LOCKDEP \
+ INIT_PERF_COUNTERS(tsk) \
}
return sum;
}
+
+/*
+ * Lock/unlock the current runqueue - to extract task statistics:
+ */
+extern void curr_rq_lock_irq_save(unsigned long *flags);
+extern void curr_rq_unlock_irq_restore(unsigned long *flags);
+extern unsigned long long __task_delta_exec(struct task_struct *tsk, int update);
extern unsigned long long task_delta_exec(struct task_struct *);
+
extern void account_user_time(struct task_struct *, cputime_t, cputime_t);
extern void account_system_time(struct task_struct *, int, cputime_t, cputime_t);
extern void account_steal_time(cputime_t);
--- /dev/null
+/*
+ * Performance counters:
+ *
+ * Copyright(C) 2008, Thomas Gleixner <tglx@linutronix.de>
+ * Copyright(C) 2008, Red Hat, Inc., Ingo Molnar
+ *
+ * Data type definitions, declarations, prototypes.
+ *
+ * Started by: Thomas Gleixner and Ingo Molnar
+ *
+ * For licencing details see kernel-base/COPYING
+ */
+#ifndef _LINUX_PERF_COUNTER_H
+#define _LINUX_PERF_COUNTER_H
+
+#include <asm/atomic.h>
+
+#ifdef CONFIG_PERF_COUNTERS
+# include <asm/perf_counter.h>
+#endif
+
+#include <linux/list.h>
+#include <linux/mutex.h>
+#include <linux/rculist.h>
+#include <linux/rcupdate.h>
+#include <linux/spinlock.h>
+
+struct task_struct;
+
+/*
+ * User-space ABI bits:
+ */
+
+/*
+ * Generalized performance counter event types, used by the hw_event.type
+ * parameter of the sys_perf_counter_open() syscall:
+ */
+enum hw_event_types {
+ /*
+ * Common hardware events, generalized by the kernel:
+ */
+ PERF_COUNT_CPU_CYCLES = 0,
+ PERF_COUNT_INSTRUCTIONS = 1,
+ PERF_COUNT_CACHE_REFERENCES = 2,
+ PERF_COUNT_CACHE_MISSES = 3,
+ PERF_COUNT_BRANCH_INSTRUCTIONS = 4,
+ PERF_COUNT_BRANCH_MISSES = 5,
+ PERF_COUNT_BUS_CYCLES = 6,
+
+ PERF_HW_EVENTS_MAX = 7,
+
+ /*
+ * Special "software" counters provided by the kernel, even if
+ * the hardware does not support performance counters. These
+ * counters measure various physical and sw events of the
+ * kernel (and allow the profiling of them as well):
+ */
+ PERF_COUNT_CPU_CLOCK = -1,
+ PERF_COUNT_TASK_CLOCK = -2,
+ PERF_COUNT_PAGE_FAULTS = -3,
+ PERF_COUNT_CONTEXT_SWITCHES = -4,
+ PERF_COUNT_CPU_MIGRATIONS = -5,
+
+ PERF_SW_EVENTS_MIN = -6,
+};
+
+/*
+ * IRQ-notification data record type:
+ */
+enum perf_counter_record_type {
+ PERF_RECORD_SIMPLE = 0,
+ PERF_RECORD_IRQ = 1,
+ PERF_RECORD_GROUP = 2,
+};
+
+/*
+ * Hardware event to monitor via a performance monitoring counter:
+ */
+struct perf_counter_hw_event {
+ s64 type;
+
+ u64 irq_period;
+ u32 record_type;
+
+ u32 disabled : 1, /* off by default */
+ nmi : 1, /* NMI sampling */
+ raw : 1, /* raw event type */
+ inherit : 1, /* children inherit it */
+ __reserved_1 : 28;
+
+ u64 __reserved_2;
+};
+
+/*
+ * Kernel-internal data types:
+ */
+
+/**
+ * struct hw_perf_counter - performance counter hardware details:
+ */
+struct hw_perf_counter {
+#ifdef CONFIG_PERF_COUNTERS
+ u64 config;
+ unsigned long config_base;
+ unsigned long counter_base;
+ int nmi;
+ unsigned int idx;
+ atomic64_t prev_count;
+ u64 irq_period;
+ atomic64_t period_left;
+#endif
+};
+
+/*
+ * Hardcoded buffer length limit for now, for IRQ-fed events:
+ */
+#define PERF_DATA_BUFLEN 2048
+
+/**
+ * struct perf_data - performance counter IRQ data sampling ...
+ */
+struct perf_data {
+ int len;
+ int rd_idx;
+ int overrun;
+ u8 data[PERF_DATA_BUFLEN];
+};
+
+struct perf_counter;
+
+/**
+ * struct hw_perf_counter_ops - performance counter hw ops
+ */
+struct hw_perf_counter_ops {
+ int (*enable) (struct perf_counter *counter);
+ void (*disable) (struct perf_counter *counter);
+ void (*read) (struct perf_counter *counter);
+};
+
+/**
+ * enum perf_counter_active_state - the states of a counter
+ */
+enum perf_counter_active_state {
+ PERF_COUNTER_STATE_OFF = -1,
+ PERF_COUNTER_STATE_INACTIVE = 0,
+ PERF_COUNTER_STATE_ACTIVE = 1,
+};
+
+struct file;
+
+/**
+ * struct perf_counter - performance counter kernel representation:
+ */
+struct perf_counter {
+#ifdef CONFIG_PERF_COUNTERS
+ struct list_head list_entry;
+ struct list_head sibling_list;
+ struct perf_counter *group_leader;
+ const struct hw_perf_counter_ops *hw_ops;
+
+ enum perf_counter_active_state state;
+ atomic64_t count;
+
+ struct perf_counter_hw_event hw_event;
+ struct hw_perf_counter hw;
+
+ struct perf_counter_context *ctx;
+ struct task_struct *task;
+ struct file *filp;
+
+ struct perf_counter *parent;
+ /*
+ * Protect attach/detach:
+ */
+ struct mutex mutex;
+
+ int oncpu;
+ int cpu;
+
+ /* read() / irq related data */
+ wait_queue_head_t waitq;
+ /* optional: for NMIs */
+ int wakeup_pending;
+ struct perf_data *irqdata;
+ struct perf_data *usrdata;
+ struct perf_data data[2];
+#endif
+};
+
+/**
+ * struct perf_counter_context - counter context structure
+ *
+ * Used as a container for task counters and CPU counters as well:
+ */
+struct perf_counter_context {
+#ifdef CONFIG_PERF_COUNTERS
+ /*
+ * Protect the list of counters:
+ */
+ spinlock_t lock;
+
+ struct list_head counter_list;
+ int nr_counters;
+ int nr_active;
+ struct task_struct *task;
+#endif
+};
+
+/**
+ * struct perf_counter_cpu_context - per cpu counter context structure
+ */
+struct perf_cpu_context {
+ struct perf_counter_context ctx;
+ struct perf_counter_context *task_ctx;
+ int active_oncpu;
+ int max_pertask;
+};
+
+/*
+ * Set by architecture code:
+ */
+extern int perf_max_counters;
+
+#ifdef CONFIG_PERF_COUNTERS
+extern const struct hw_perf_counter_ops *
+hw_perf_counter_init(struct perf_counter *counter);
+
+extern void perf_counter_task_sched_in(struct task_struct *task, int cpu);
+extern void perf_counter_task_sched_out(struct task_struct *task, int cpu);
+extern void perf_counter_task_tick(struct task_struct *task, int cpu);
+extern void perf_counter_init_task(struct task_struct *child);
+extern void perf_counter_exit_task(struct task_struct *child);
+extern void perf_counter_notify(struct pt_regs *regs);
+extern void perf_counter_print_debug(void);
+extern u64 hw_perf_save_disable(void);
+extern void hw_perf_restore(u64 ctrl);
+extern int perf_counter_task_disable(void);
+extern int perf_counter_task_enable(void);
+
+#else
+static inline void
+perf_counter_task_sched_in(struct task_struct *task, int cpu) { }
+static inline void
+perf_counter_task_sched_out(struct task_struct *task, int cpu) { }
+static inline void
+perf_counter_task_tick(struct task_struct *task, int cpu) { }
+static inline void perf_counter_init_task(struct task_struct *child) { }
+static inline void perf_counter_exit_task(struct task_struct *child) { }
+static inline void perf_counter_notify(struct pt_regs *regs) { }
+static inline void perf_counter_print_debug(void) { }
+static inline void hw_perf_restore(u64 ctrl) { }
+static inline u64 hw_perf_save_disable(void) { return 0; }
+static inline int perf_counter_task_disable(void) { return -EINVAL; }
+static inline int perf_counter_task_enable(void) { return -EINVAL; }
+#endif
+
+#endif /* _LINUX_PERF_COUNTER_H */
#define PR_SET_TIMERSLACK 29
#define PR_GET_TIMERSLACK 30
+#define PR_TASK_PERF_COUNTERS_DISABLE 31
+#define PR_TASK_PERF_COUNTERS_ENABLE 32
+
#endif /* _LINUX_PRCTL_H */
#include <linux/fs_struct.h>
#include <linux/compiler.h>
#include <linux/completion.h>
+#include <linux/perf_counter.h>
#include <linux/pid.h>
#include <linux/percpu.h>
#include <linux/topology.h>
u64 last_wakeup;
u64 avg_overlap;
+ u64 nr_migrations;
+
#ifdef CONFIG_SCHEDSTATS
u64 wait_start;
u64 wait_max;
u64 exec_max;
u64 slice_max;
- u64 nr_migrations;
u64 nr_migrations_cold;
u64 nr_failed_migrations_affine;
u64 nr_failed_migrations_running;
struct list_head pi_state_list;
struct futex_pi_state *pi_state_cache;
#endif
+ struct perf_counter_context perf_counter_ctx;
#ifdef CONFIG_NUMA
struct mempolicy *mempolicy;
short il_next;
#define TASK_SIZE_OF(tsk) TASK_SIZE
#endif
+/*
+ * Call the function if the target task is executing on a CPU right now:
+ */
+extern void task_oncpu_function_call(struct task_struct *p,
+ void (*func) (void *info), void *info);
+
+
#ifdef CONFIG_MM_OWNER
extern void mm_update_next_owner(struct mm_struct *mm);
extern void mm_init_owner(struct mm_struct *mm, struct task_struct *p);
struct compat_timeval;
struct robust_list_head;
struct getcpu_cache;
+struct perf_counter_hw_event;
#include <linux/types.h>
#include <linux/aio_abi.h>
int kernel_execve(const char *filename, char *const argv[], char *const envp[]);
+
+asmlinkage int sys_perf_counter_open(
+
+ struct perf_counter_hw_event *hw_event_uptr __user,
+ pid_t pid,
+ int cpu,
+ int group_fd);
#endif
by some high performance threaded applications. Disabling
this option saves about 7k.
+config HAVE_PERF_COUNTERS
+ bool
+
+menu "Performance Counters"
+
+config PERF_COUNTERS
+ bool "Kernel Performance Counters"
+ depends on HAVE_PERF_COUNTERS
+ default y
+ select ANON_INODES
+ help
+ Enable kernel support for performance counter hardware.
+
+ Performance counters are special hardware registers available
+ on most modern CPUs. These registers count the number of certain
+ types of hw events: such as instructions executed, cachemisses
+ suffered, or branches mis-predicted - without slowing down the
+ kernel or applications. These registers can also trigger interrupts
+ when a threshold number of events have passed - and can thus be
+ used to profile the code that runs on that CPU.
+
+ The Linux Performance Counter subsystem provides an abstraction of
+ these hardware capabilities, available via a system call. It
+ provides per task and per CPU counters, and it provides event
+ capabilities on top of those.
+
+ Say Y if unsure.
+
+endmenu
+
config VM_EVENT_COUNTERS
default y
bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
obj-$(CONFIG_FUNCTION_TRACER) += trace/
obj-$(CONFIG_TRACING) += trace/
obj-$(CONFIG_SMP) += sched_cpupri.o
+obj-$(CONFIG_PERF_COUNTERS) += perf_counter.o
ifneq ($(CONFIG_SCHED_OMIT_FRAME_POINTER),y)
# According to Alan Modra <alan@linuxcare.com.au>, the -fno-omit-frame-pointer is
{
struct task_struct *tsk = container_of(rhp, struct task_struct, rcu);
+#ifdef CONFIG_PERF_COUNTERS
+ WARN_ON_ONCE(!list_empty(&tsk->perf_counter_ctx.counter_list));
+#endif
trace_sched_process_free(tsk);
put_task_struct(tsk);
}
tsk->mempolicy = NULL;
#endif
#ifdef CONFIG_FUTEX
- /*
- * This must happen late, after the PID is not
- * hashed anymore:
- */
if (unlikely(!list_empty(&tsk->pi_state_list)))
exit_pi_state_list(tsk);
if (unlikely(current->pi_state_cache))
*/
read_unlock(&tasklist_lock);
+ /*
+ * Flush inherited counters to the parent - before the parent
+ * gets woken up by child-exit notifications.
+ */
+ perf_counter_exit_task(p);
+
retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0;
status = (p->signal->flags & SIGNAL_GROUP_EXIT)
? p->signal->group_exit_code : p->exit_code;
goto fork_out;
rt_mutex_init_task(p);
+ perf_counter_init_task(p);
#ifdef CONFIG_PROVE_LOCKING
DEBUG_LOCKS_WARN_ON(!p->hardirqs_enabled);
--- /dev/null
+/*
+ * Performance counter core code
+ *
+ * Copyright(C) 2008 Thomas Gleixner <tglx@linutronix.de>
+ * Copyright(C) 2008 Red Hat, Inc., Ingo Molnar
+ *
+ * For licencing details see kernel-base/COPYING
+ */
+
+#include <linux/fs.h>
+#include <linux/cpu.h>
+#include <linux/smp.h>
+#include <linux/file.h>
+#include <linux/poll.h>
+#include <linux/sysfs.h>
+#include <linux/ptrace.h>
+#include <linux/percpu.h>
+#include <linux/uaccess.h>
+#include <linux/syscalls.h>
+#include <linux/anon_inodes.h>
+#include <linux/kernel_stat.h>
+#include <linux/perf_counter.h>
+
+/*
+ * Each CPU has a list of per CPU counters:
+ */
+DEFINE_PER_CPU(struct perf_cpu_context, perf_cpu_context);
+
+int perf_max_counters __read_mostly = 1;
+static int perf_reserved_percpu __read_mostly;
+static int perf_overcommit __read_mostly = 1;
+
+/*
+ * Mutex for (sysadmin-configurable) counter reservations:
+ */
+static DEFINE_MUTEX(perf_resource_mutex);
+
+/*
+ * Architecture provided APIs - weak aliases:
+ */
+extern __weak const struct hw_perf_counter_ops *
+hw_perf_counter_init(struct perf_counter *counter)
+{
+ return ERR_PTR(-EINVAL);
+}
+
+u64 __weak hw_perf_save_disable(void) { return 0; }
+void __weak hw_perf_restore(u64 ctrl) { barrier(); }
+void __weak hw_perf_counter_setup(void) { barrier(); }
+
+static void
+list_add_counter(struct perf_counter *counter, struct perf_counter_context *ctx)
+{
+ struct perf_counter *group_leader = counter->group_leader;
+
+ /*
+ * Depending on whether it is a standalone or sibling counter,
+ * add it straight to the context's counter list, or to the group
+ * leader's sibling list:
+ */
+ if (counter->group_leader == counter)
+ list_add_tail(&counter->list_entry, &ctx->counter_list);
+ else
+ list_add_tail(&counter->list_entry, &group_leader->sibling_list);
+}
+
+static void
+list_del_counter(struct perf_counter *counter, struct perf_counter_context *ctx)
+{
+ struct perf_counter *sibling, *tmp;
+
+ list_del_init(&counter->list_entry);
+
+ /*
+ * If this was a group counter with sibling counters then
+ * upgrade the siblings to singleton counters by adding them
+ * to the context list directly:
+ */
+ list_for_each_entry_safe(sibling, tmp,
+ &counter->sibling_list, list_entry) {
+
+ list_del_init(&sibling->list_entry);
+ list_add_tail(&sibling->list_entry, &ctx->counter_list);
+ sibling->group_leader = sibling;
+ }
+}
+
+/*
+ * Cross CPU call to remove a performance counter
+ *
+ * We disable the counter on the hardware level first. After that we
+ * remove it from the context list.
+ */
+static void __perf_counter_remove_from_context(void *info)
+{
+ struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
+ struct perf_counter *counter = info;
+ struct perf_counter_context *ctx = counter->ctx;
+ unsigned long flags;
+ u64 perf_flags;
+
+ /*
+ * If this is a task context, we need to check whether it is
+ * the current task context of this cpu. If not it has been
+ * scheduled out before the smp call arrived.
+ */
+ if (ctx->task && cpuctx->task_ctx != ctx)
+ return;
+
+ curr_rq_lock_irq_save(&flags);
+ spin_lock(&ctx->lock);
+
+ if (counter->state == PERF_COUNTER_STATE_ACTIVE) {
+ counter->state = PERF_COUNTER_STATE_INACTIVE;
+ counter->hw_ops->disable(counter);
+ ctx->nr_active--;
+ cpuctx->active_oncpu--;
+ counter->task = NULL;
+ counter->oncpu = -1;
+ }
+ ctx->nr_counters--;
+
+ /*
+ * Protect the list operation against NMI by disabling the
+ * counters on a global level. NOP for non NMI based counters.
+ */
+ perf_flags = hw_perf_save_disable();
+ list_del_counter(counter, ctx);
+ hw_perf_restore(perf_flags);
+
+ if (!ctx->task) {
+ /*
+ * Allow more per task counters with respect to the
+ * reservation:
+ */
+ cpuctx->max_pertask =
+ min(perf_max_counters - ctx->nr_counters,
+ perf_max_counters - perf_reserved_percpu);
+ }
+
+ spin_unlock(&ctx->lock);
+ curr_rq_unlock_irq_restore(&flags);
+}
+
+
+/*
+ * Remove the counter from a task's (or a CPU's) list of counters.
+ *
+ * Must be called with counter->mutex held.
+ *
+ * CPU counters are removed with a smp call. For task counters we only
+ * call when the task is on a CPU.
+ */
+static void perf_counter_remove_from_context(struct perf_counter *counter)
+{
+ struct perf_counter_context *ctx = counter->ctx;
+ struct task_struct *task = ctx->task;
+
+ if (!task) {
+ /*
+ * Per cpu counters are removed via an smp call and
+ * the removal is always sucessful.
+ */
+ smp_call_function_single(counter->cpu,
+ __perf_counter_remove_from_context,
+ counter, 1);
+ return;
+ }
+
+retry:
+ task_oncpu_function_call(task, __perf_counter_remove_from_context,
+ counter);
+
+ spin_lock_irq(&ctx->lock);
+ /*
+ * If the context is active we need to retry the smp call.
+ */
+ if (ctx->nr_active && !list_empty(&counter->list_entry)) {
+ spin_unlock_irq(&ctx->lock);
+ goto retry;
+ }
+
+ /*
+ * The lock prevents that this context is scheduled in so we
+ * can remove the counter safely, if the call above did not
+ * succeed.
+ */
+ if (!list_empty(&counter->list_entry)) {
+ ctx->nr_counters--;
+ list_del_counter(counter, ctx);
+ counter->task = NULL;
+ }
+ spin_unlock_irq(&ctx->lock);
+}
+
+static int
+counter_sched_in(struct perf_counter *counter,
+ struct perf_cpu_context *cpuctx,
+ struct perf_counter_context *ctx,
+ int cpu)
+{
+ if (counter->state == PERF_COUNTER_STATE_OFF)
+ return 0;
+
+ counter->state = PERF_COUNTER_STATE_ACTIVE;
+ counter->oncpu = cpu; /* TODO: put 'cpu' into cpuctx->cpu */
+ /*
+ * The new state must be visible before we turn it on in the hardware:
+ */
+ smp_wmb();
+
+ if (counter->hw_ops->enable(counter)) {
+ counter->state = PERF_COUNTER_STATE_INACTIVE;
+ counter->oncpu = -1;
+ return -EAGAIN;
+ }
+
+ cpuctx->active_oncpu++;
+ ctx->nr_active++;
+
+ return 0;
+}
+
+/*
+ * Cross CPU call to install and enable a performance counter
+ */
+static void __perf_install_in_context(void *info)
+{
+ struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
+ struct perf_counter *counter = info;
+ struct perf_counter_context *ctx = counter->ctx;
+ int cpu = smp_processor_id();
+ unsigned long flags;
+ u64 perf_flags;
+
+ /*
+ * If this is a task context, we need to check whether it is
+ * the current task context of this cpu. If not it has been
+ * scheduled out before the smp call arrived.
+ */
+ if (ctx->task && cpuctx->task_ctx != ctx)
+ return;
+
+ curr_rq_lock_irq_save(&flags);
+ spin_lock(&ctx->lock);
+
+ /*
+ * Protect the list operation against NMI by disabling the
+ * counters on a global level. NOP for non NMI based counters.
+ */
+ perf_flags = hw_perf_save_disable();
+
+ list_add_counter(counter, ctx);
+ ctx->nr_counters++;
+
+ counter_sched_in(counter, cpuctx, ctx, cpu);
+
+ if (!ctx->task && cpuctx->max_pertask)
+ cpuctx->max_pertask--;
+
+ hw_perf_restore(perf_flags);
+
+ spin_unlock(&ctx->lock);
+ curr_rq_unlock_irq_restore(&flags);
+}
+
+/*
+ * Attach a performance counter to a context
+ *
+ * First we add the counter to the list with the hardware enable bit
+ * in counter->hw_config cleared.
+ *
+ * If the counter is attached to a task which is on a CPU we use a smp
+ * call to enable it in the task context. The task might have been
+ * scheduled away, but we check this in the smp call again.
+ */
+static void
+perf_install_in_context(struct perf_counter_context *ctx,
+ struct perf_counter *counter,
+ int cpu)
+{
+ struct task_struct *task = ctx->task;
+
+ counter->ctx = ctx;
+ if (!task) {
+ /*
+ * Per cpu counters are installed via an smp call and
+ * the install is always sucessful.
+ */
+ smp_call_function_single(cpu, __perf_install_in_context,
+ counter, 1);
+ return;
+ }
+
+ counter->task = task;
+retry:
+ task_oncpu_function_call(task, __perf_install_in_context,
+ counter);
+
+ spin_lock_irq(&ctx->lock);
+ /*
+ * we need to retry the smp call.
+ */
+ if (ctx->nr_active && list_empty(&counter->list_entry)) {
+ spin_unlock_irq(&ctx->lock);
+ goto retry;
+ }
+
+ /*
+ * The lock prevents that this context is scheduled in so we
+ * can add the counter safely, if it the call above did not
+ * succeed.
+ */
+ if (list_empty(&counter->list_entry)) {
+ list_add_counter(counter, ctx);
+ ctx->nr_counters++;
+ }
+ spin_unlock_irq(&ctx->lock);
+}
+
+static void
+counter_sched_out(struct perf_counter *counter,
+ struct perf_cpu_context *cpuctx,
+ struct perf_counter_context *ctx)
+{
+ if (counter->state != PERF_COUNTER_STATE_ACTIVE)
+ return;
+
+ counter->state = PERF_COUNTER_STATE_INACTIVE;
+ counter->hw_ops->disable(counter);
+ counter->oncpu = -1;
+
+ cpuctx->active_oncpu--;
+ ctx->nr_active--;
+}
+
+static void
+group_sched_out(struct perf_counter *group_counter,
+ struct perf_cpu_context *cpuctx,
+ struct perf_counter_context *ctx)
+{
+ struct perf_counter *counter;
+
+ counter_sched_out(group_counter, cpuctx, ctx);
+
+ /*
+ * Schedule out siblings (if any):
+ */
+ list_for_each_entry(counter, &group_counter->sibling_list, list_entry)
+ counter_sched_out(counter, cpuctx, ctx);
+}
+
+void __perf_counter_sched_out(struct perf_counter_context *ctx,
+ struct perf_cpu_context *cpuctx)
+{
+ struct perf_counter *counter;
+
+ if (likely(!ctx->nr_counters))
+ return;
+
+ spin_lock(&ctx->lock);
+ if (ctx->nr_active) {
+ list_for_each_entry(counter, &ctx->counter_list, list_entry)
+ group_sched_out(counter, cpuctx, ctx);
+ }
+ spin_unlock(&ctx->lock);
+}
+
+/*
+ * Called from scheduler to remove the counters of the current task,
+ * with interrupts disabled.
+ *
+ * We stop each counter and update the counter value in counter->count.
+ *
+ * This does not protect us against NMI, but disable()
+ * sets the disabled bit in the control field of counter _before_
+ * accessing the counter control register. If a NMI hits, then it will
+ * not restart the counter.
+ */
+void perf_counter_task_sched_out(struct task_struct *task, int cpu)
+{
+ struct perf_cpu_context *cpuctx = &per_cpu(perf_cpu_context, cpu);
+ struct perf_counter_context *ctx = &task->perf_counter_ctx;
+
+ if (likely(!cpuctx->task_ctx))
+ return;
+
+ __perf_counter_sched_out(ctx, cpuctx);
+
+ cpuctx->task_ctx = NULL;
+}
+
+static void perf_counter_cpu_sched_out(struct perf_cpu_context *cpuctx)
+{
+ __perf_counter_sched_out(&cpuctx->ctx, cpuctx);
+}
+
+static int
+group_sched_in(struct perf_counter *group_counter,
+ struct perf_cpu_context *cpuctx,
+ struct perf_counter_context *ctx,
+ int cpu)
+{
+ struct perf_counter *counter, *partial_group;
+ int ret = 0;
+
+ if (counter_sched_in(group_counter, cpuctx, ctx, cpu))
+ return -EAGAIN;
+
+ /*
+ * Schedule in siblings as one group (if any):
+ */
+ list_for_each_entry(counter, &group_counter->sibling_list, list_entry) {
+ if (counter_sched_in(counter, cpuctx, ctx, cpu)) {
+ partial_group = counter;
+ goto group_error;
+ }
+ ret = -EAGAIN;
+ }
+
+ return ret;
+
+group_error:
+ /*
+ * Groups can be scheduled in as one unit only, so undo any
+ * partial group before returning:
+ */
+ list_for_each_entry(counter, &group_counter->sibling_list, list_entry) {
+ if (counter == partial_group)
+ break;
+ counter_sched_out(counter, cpuctx, ctx);
+ }
+ counter_sched_out(group_counter, cpuctx, ctx);
+
+ return -EAGAIN;
+}
+
+static void
+__perf_counter_sched_in(struct perf_counter_context *ctx,
+ struct perf_cpu_context *cpuctx, int cpu)
+{
+ struct perf_counter *counter;
+
+ if (likely(!ctx->nr_counters))
+ return;
+
+ spin_lock(&ctx->lock);
+ list_for_each_entry(counter, &ctx->counter_list, list_entry) {
+ /*
+ * Listen to the 'cpu' scheduling filter constraint
+ * of counters:
+ */
+ if (counter->cpu != -1 && counter->cpu != cpu)
+ continue;
+
+ /*
+ * If we scheduled in a group atomically and
+ * exclusively, break out:
+ */
+ if (group_sched_in(counter, cpuctx, ctx, cpu))
+ break;
+ }
+ spin_unlock(&ctx->lock);
+}
+
+/*
+ * Called from scheduler to add the counters of the current task
+ * with interrupts disabled.
+ *
+ * We restore the counter value and then enable it.
+ *
+ * This does not protect us against NMI, but enable()
+ * sets the enabled bit in the control field of counter _before_
+ * accessing the counter control register. If a NMI hits, then it will
+ * keep the counter running.
+ */
+void perf_counter_task_sched_in(struct task_struct *task, int cpu)
+{
+ struct perf_cpu_context *cpuctx = &per_cpu(perf_cpu_context, cpu);
+ struct perf_counter_context *ctx = &task->perf_counter_ctx;
+
+ __perf_counter_sched_in(ctx, cpuctx, cpu);
+ cpuctx->task_ctx = ctx;
+}
+
+static void perf_counter_cpu_sched_in(struct perf_cpu_context *cpuctx, int cpu)
+{
+ struct perf_counter_context *ctx = &cpuctx->ctx;
+
+ __perf_counter_sched_in(ctx, cpuctx, cpu);
+}
+
+int perf_counter_task_disable(void)
+{
+ struct task_struct *curr = current;
+ struct perf_counter_context *ctx = &curr->perf_counter_ctx;
+ struct perf_counter *counter;
+ unsigned long flags;
+ u64 perf_flags;
+ int cpu;
+
+ if (likely(!ctx->nr_counters))
+ return 0;
+
+ curr_rq_lock_irq_save(&flags);
+ cpu = smp_processor_id();
+
+ /* force the update of the task clock: */
+ __task_delta_exec(curr, 1);
+
+ perf_counter_task_sched_out(curr, cpu);
+
+ spin_lock(&ctx->lock);
+
+ /*
+ * Disable all the counters:
+ */
+ perf_flags = hw_perf_save_disable();
+
+ list_for_each_entry(counter, &ctx->counter_list, list_entry)
+ counter->state = PERF_COUNTER_STATE_OFF;
+
+ hw_perf_restore(perf_flags);
+
+ spin_unlock(&ctx->lock);
+
+ curr_rq_unlock_irq_restore(&flags);
+
+ return 0;
+}
+
+int perf_counter_task_enable(void)
+{
+ struct task_struct *curr = current;
+ struct perf_counter_context *ctx = &curr->perf_counter_ctx;
+ struct perf_counter *counter;
+ unsigned long flags;
+ u64 perf_flags;
+ int cpu;
+
+ if (likely(!ctx->nr_counters))
+ return 0;
+
+ curr_rq_lock_irq_save(&flags);
+ cpu = smp_processor_id();
+
+ /* force the update of the task clock: */
+ __task_delta_exec(curr, 1);
+
+ perf_counter_task_sched_out(curr, cpu);
+
+ spin_lock(&ctx->lock);
+
+ /*
+ * Disable all the counters:
+ */
+ perf_flags = hw_perf_save_disable();
+
+ list_for_each_entry(counter, &ctx->counter_list, list_entry) {
+ if (counter->state != PERF_COUNTER_STATE_OFF)
+ continue;
+ counter->state = PERF_COUNTER_STATE_INACTIVE;
+ counter->hw_event.disabled = 0;
+ }
+ hw_perf_restore(perf_flags);
+
+ spin_unlock(&ctx->lock);
+
+ perf_counter_task_sched_in(curr, cpu);
+
+ curr_rq_unlock_irq_restore(&flags);
+
+ return 0;
+}
+
+/*
+ * Round-robin a context's counters:
+ */
+static void rotate_ctx(struct perf_counter_context *ctx)
+{
+ struct perf_counter *counter;
+ u64 perf_flags;
+
+ if (!ctx->nr_counters)
+ return;
+
+ spin_lock(&ctx->lock);
+ /*
+ * Rotate the first entry last (works just fine for group counters too):
+ */
+ perf_flags = hw_perf_save_disable();
+ list_for_each_entry(counter, &ctx->counter_list, list_entry) {
+ list_del(&counter->list_entry);
+ list_add_tail(&counter->list_entry, &ctx->counter_list);
+ break;
+ }
+ hw_perf_restore(perf_flags);
+
+ spin_unlock(&ctx->lock);
+}
+
+void perf_counter_task_tick(struct task_struct *curr, int cpu)
+{
+ struct perf_cpu_context *cpuctx = &per_cpu(perf_cpu_context, cpu);
+ struct perf_counter_context *ctx = &curr->perf_counter_ctx;
+ const int rotate_percpu = 0;
+
+ if (rotate_percpu)
+ perf_counter_cpu_sched_out(cpuctx);
+ perf_counter_task_sched_out(curr, cpu);
+
+ if (rotate_percpu)
+ rotate_ctx(&cpuctx->ctx);
+ rotate_ctx(ctx);
+
+ if (rotate_percpu)
+ perf_counter_cpu_sched_in(cpuctx, cpu);
+ perf_counter_task_sched_in(curr, cpu);
+}
+
+/*
+ * Cross CPU call to read the hardware counter
+ */
+static void __read(void *info)
+{
+ struct perf_counter *counter = info;
+ unsigned long flags;
+
+ curr_rq_lock_irq_save(&flags);
+ counter->hw_ops->read(counter);
+ curr_rq_unlock_irq_restore(&flags);
+}
+
+static u64 perf_counter_read(struct perf_counter *counter)
+{
+ /*
+ * If counter is enabled and currently active on a CPU, update the
+ * value in the counter structure:
+ */
+ if (counter->state == PERF_COUNTER_STATE_ACTIVE) {
+ smp_call_function_single(counter->oncpu,
+ __read, counter, 1);
+ }
+
+ return atomic64_read(&counter->count);
+}
+
+/*
+ * Cross CPU call to switch performance data pointers
+ */
+static void __perf_switch_irq_data(void *info)
+{
+ struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
+ struct perf_counter *counter = info;
+ struct perf_counter_context *ctx = counter->ctx;
+ struct perf_data *oldirqdata = counter->irqdata;
+
+ /*
+ * If this is a task context, we need to check whether it is
+ * the current task context of this cpu. If not it has been
+ * scheduled out before the smp call arrived.
+ */
+ if (ctx->task) {
+ if (cpuctx->task_ctx != ctx)
+ return;
+ spin_lock(&ctx->lock);
+ }
+
+ /* Change the pointer NMI safe */
+ atomic_long_set((atomic_long_t *)&counter->irqdata,
+ (unsigned long) counter->usrdata);
+ counter->usrdata = oldirqdata;
+
+ if (ctx->task)
+ spin_unlock(&ctx->lock);
+}
+
+static struct perf_data *perf_switch_irq_data(struct perf_counter *counter)
+{
+ struct perf_counter_context *ctx = counter->ctx;
+ struct perf_data *oldirqdata = counter->irqdata;
+ struct task_struct *task = ctx->task;
+
+ if (!task) {
+ smp_call_function_single(counter->cpu,
+ __perf_switch_irq_data,
+ counter, 1);
+ return counter->usrdata;
+ }
+
+retry:
+ spin_lock_irq(&ctx->lock);
+ if (counter->state != PERF_COUNTER_STATE_ACTIVE) {
+ counter->irqdata = counter->usrdata;
+ counter->usrdata = oldirqdata;
+ spin_unlock_irq(&ctx->lock);
+ return oldirqdata;
+ }
+ spin_unlock_irq(&ctx->lock);
+ task_oncpu_function_call(task, __perf_switch_irq_data, counter);
+ /* Might have failed, because task was scheduled out */
+ if (counter->irqdata == oldirqdata)
+ goto retry;
+
+ return counter->usrdata;
+}
+
+static void put_context(struct perf_counter_context *ctx)
+{
+ if (ctx->task)
+ put_task_struct(ctx->task);
+}
+
+static struct perf_counter_context *find_get_context(pid_t pid, int cpu)
+{
+ struct perf_cpu_context *cpuctx;
+ struct perf_counter_context *ctx;
+ struct task_struct *task;
+
+ /*
+ * If cpu is not a wildcard then this is a percpu counter:
+ */
+ if (cpu != -1) {
+ /* Must be root to operate on a CPU counter: */
+ if (!capable(CAP_SYS_ADMIN))
+ return ERR_PTR(-EACCES);
+
+ if (cpu < 0 || cpu > num_possible_cpus())
+ return ERR_PTR(-EINVAL);
+
+ /*
+ * We could be clever and allow to attach a counter to an
+ * offline CPU and activate it when the CPU comes up, but
+ * that's for later.
+ */
+ if (!cpu_isset(cpu, cpu_online_map))
+ return ERR_PTR(-ENODEV);
+
+ cpuctx = &per_cpu(perf_cpu_context, cpu);
+ ctx = &cpuctx->ctx;
+
+ return ctx;
+ }
+
+ rcu_read_lock();
+ if (!pid)
+ task = current;
+ else
+ task = find_task_by_vpid(pid);
+ if (task)
+ get_task_struct(task);
+ rcu_read_unlock();
+
+ if (!task)
+ return ERR_PTR(-ESRCH);
+
+ ctx = &task->perf_counter_ctx;
+ ctx->task = task;
+
+ /* Reuse ptrace permission checks for now. */
+ if (!ptrace_may_access(task, PTRACE_MODE_READ)) {
+ put_context(ctx);
+ return ERR_PTR(-EACCES);
+ }
+
+ return ctx;
+}
+
+/*
+ * Called when the last reference to the file is gone.
+ */
+static int perf_release(struct inode *inode, struct file *file)
+{
+ struct perf_counter *counter = file->private_data;
+ struct perf_counter_context *ctx = counter->ctx;
+
+ file->private_data = NULL;
+
+ mutex_lock(&counter->mutex);
+
+ perf_counter_remove_from_context(counter);
+ put_context(ctx);
+
+ mutex_unlock(&counter->mutex);
+
+ kfree(counter);
+
+ return 0;
+}
+
+/*
+ * Read the performance counter - simple non blocking version for now
+ */
+static ssize_t
+perf_read_hw(struct perf_counter *counter, char __user *buf, size_t count)
+{
+ u64 cntval;
+
+ if (count != sizeof(cntval))
+ return -EINVAL;
+
+ mutex_lock(&counter->mutex);
+ cntval = perf_counter_read(counter);
+ mutex_unlock(&counter->mutex);
+
+ return put_user(cntval, (u64 __user *) buf) ? -EFAULT : sizeof(cntval);
+}
+
+static ssize_t
+perf_copy_usrdata(struct perf_data *usrdata, char __user *buf, size_t count)
+{
+ if (!usrdata->len)
+ return 0;
+
+ count = min(count, (size_t)usrdata->len);
+ if (copy_to_user(buf, usrdata->data + usrdata->rd_idx, count))
+ return -EFAULT;
+
+ /* Adjust the counters */
+ usrdata->len -= count;
+ if (!usrdata->len)
+ usrdata->rd_idx = 0;
+ else
+ usrdata->rd_idx += count;
+
+ return count;
+}
+
+static ssize_t
+perf_read_irq_data(struct perf_counter *counter,
+ char __user *buf,
+ size_t count,
+ int nonblocking)
+{
+ struct perf_data *irqdata, *usrdata;
+ DECLARE_WAITQUEUE(wait, current);
+ ssize_t res;
+
+ irqdata = counter->irqdata;
+ usrdata = counter->usrdata;
+
+ if (usrdata->len + irqdata->len >= count)
+ goto read_pending;
+
+ if (nonblocking)
+ return -EAGAIN;
+
+ spin_lock_irq(&counter->waitq.lock);
+ __add_wait_queue(&counter->waitq, &wait);
+ for (;;) {
+ set_current_state(TASK_INTERRUPTIBLE);
+ if (usrdata->len + irqdata->len >= count)
+ break;
+
+ if (signal_pending(current))
+ break;
+
+ spin_unlock_irq(&counter->waitq.lock);
+ schedule();
+ spin_lock_irq(&counter->waitq.lock);
+ }
+ __remove_wait_queue(&counter->waitq, &wait);
+ __set_current_state(TASK_RUNNING);
+ spin_unlock_irq(&counter->waitq.lock);
+
+ if (usrdata->len + irqdata->len < count)
+ return -ERESTARTSYS;
+read_pending:
+ mutex_lock(&counter->mutex);
+
+ /* Drain pending data first: */
+ res = perf_copy_usrdata(usrdata, buf, count);
+ if (res < 0 || res == count)
+ goto out;
+
+ /* Switch irq buffer: */
+ usrdata = perf_switch_irq_data(counter);
+ if (perf_copy_usrdata(usrdata, buf + res, count - res) < 0) {
+ if (!res)
+ res = -EFAULT;
+ } else {
+ res = count;
+ }
+out:
+ mutex_unlock(&counter->mutex);
+
+ return res;
+}
+
+static ssize_t
+perf_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
+{
+ struct perf_counter *counter = file->private_data;
+
+ switch (counter->hw_event.record_type) {
+ case PERF_RECORD_SIMPLE:
+ return perf_read_hw(counter, buf, count);
+
+ case PERF_RECORD_IRQ:
+ case PERF_RECORD_GROUP:
+ return perf_read_irq_data(counter, buf, count,
+ file->f_flags & O_NONBLOCK);
+ }
+ return -EINVAL;
+}
+
+static unsigned int perf_poll(struct file *file, poll_table *wait)
+{
+ struct perf_counter *counter = file->private_data;
+ unsigned int events = 0;
+ unsigned long flags;
+
+ poll_wait(file, &counter->waitq, wait);
+
+ spin_lock_irqsave(&counter->waitq.lock, flags);
+ if (counter->usrdata->len || counter->irqdata->len)
+ events |= POLLIN;
+ spin_unlock_irqrestore(&counter->waitq.lock, flags);
+
+ return events;
+}
+
+static const struct file_operations perf_fops = {
+ .release = perf_release,
+ .read = perf_read,
+ .poll = perf_poll,
+};
+
+static int cpu_clock_perf_counter_enable(struct perf_counter *counter)
+{
+ return 0;
+}
+
+static void cpu_clock_perf_counter_disable(struct perf_counter *counter)
+{
+}
+
+static void cpu_clock_perf_counter_read(struct perf_counter *counter)
+{
+ int cpu = raw_smp_processor_id();
+
+ atomic64_set(&counter->count, cpu_clock(cpu));
+}
+
+static const struct hw_perf_counter_ops perf_ops_cpu_clock = {
+ .enable = cpu_clock_perf_counter_enable,
+ .disable = cpu_clock_perf_counter_disable,
+ .read = cpu_clock_perf_counter_read,
+};
+
+/*
+ * Called from within the scheduler:
+ */
+static u64 task_clock_perf_counter_val(struct perf_counter *counter, int update)
+{
+ struct task_struct *curr = counter->task;
+ u64 delta;
+
+ delta = __task_delta_exec(curr, update);
+
+ return curr->se.sum_exec_runtime + delta;
+}
+
+static void task_clock_perf_counter_update(struct perf_counter *counter, u64 now)
+{
+ u64 prev;
+ s64 delta;
+
+ prev = atomic64_read(&counter->hw.prev_count);
+
+ atomic64_set(&counter->hw.prev_count, now);
+
+ delta = now - prev;
+
+ atomic64_add(delta, &counter->count);
+}
+
+static void task_clock_perf_counter_read(struct perf_counter *counter)
+{
+ u64 now = task_clock_perf_counter_val(counter, 1);
+
+ task_clock_perf_counter_update(counter, now);
+}
+
+static int task_clock_perf_counter_enable(struct perf_counter *counter)
+{
+ u64 now = task_clock_perf_counter_val(counter, 0);
+
+ atomic64_set(&counter->hw.prev_count, now);
+
+ return 0;
+}
+
+static void task_clock_perf_counter_disable(struct perf_counter *counter)
+{
+ u64 now = task_clock_perf_counter_val(counter, 0);
+
+ task_clock_perf_counter_update(counter, now);
+}
+
+static const struct hw_perf_counter_ops perf_ops_task_clock = {
+ .enable = task_clock_perf_counter_enable,
+ .disable = task_clock_perf_counter_disable,
+ .read = task_clock_perf_counter_read,
+};
+
+static u64 get_page_faults(void)
+{
+ struct task_struct *curr = current;
+
+ return curr->maj_flt + curr->min_flt;
+}
+
+static void page_faults_perf_counter_update(struct perf_counter *counter)
+{
+ u64 prev, now;
+ s64 delta;
+
+ prev = atomic64_read(&counter->hw.prev_count);
+ now = get_page_faults();
+
+ atomic64_set(&counter->hw.prev_count, now);
+
+ delta = now - prev;
+
+ atomic64_add(delta, &counter->count);
+}
+
+static void page_faults_perf_counter_read(struct perf_counter *counter)
+{
+ page_faults_perf_counter_update(counter);
+}
+
+static int page_faults_perf_counter_enable(struct perf_counter *counter)
+{
+ /*
+ * page-faults is a per-task value already,
+ * so we dont have to clear it on switch-in.
+ */
+
+ return 0;
+}
+
+static void page_faults_perf_counter_disable(struct perf_counter *counter)
+{
+ page_faults_perf_counter_update(counter);
+}
+
+static const struct hw_perf_counter_ops perf_ops_page_faults = {
+ .enable = page_faults_perf_counter_enable,
+ .disable = page_faults_perf_counter_disable,
+ .read = page_faults_perf_counter_read,
+};
+
+static u64 get_context_switches(void)
+{
+ struct task_struct *curr = current;
+
+ return curr->nvcsw + curr->nivcsw;
+}
+
+static void context_switches_perf_counter_update(struct perf_counter *counter)
+{
+ u64 prev, now;
+ s64 delta;
+
+ prev = atomic64_read(&counter->hw.prev_count);
+ now = get_context_switches();
+
+ atomic64_set(&counter->hw.prev_count, now);
+
+ delta = now - prev;
+
+ atomic64_add(delta, &counter->count);
+}
+
+static void context_switches_perf_counter_read(struct perf_counter *counter)
+{
+ context_switches_perf_counter_update(counter);
+}
+
+static int context_switches_perf_counter_enable(struct perf_counter *counter)
+{
+ /*
+ * ->nvcsw + curr->nivcsw is a per-task value already,
+ * so we dont have to clear it on switch-in.
+ */
+
+ return 0;
+}
+
+static void context_switches_perf_counter_disable(struct perf_counter *counter)
+{
+ context_switches_perf_counter_update(counter);
+}
+
+static const struct hw_perf_counter_ops perf_ops_context_switches = {
+ .enable = context_switches_perf_counter_enable,
+ .disable = context_switches_perf_counter_disable,
+ .read = context_switches_perf_counter_read,
+};
+
+static inline u64 get_cpu_migrations(void)
+{
+ return current->se.nr_migrations;
+}
+
+static void cpu_migrations_perf_counter_update(struct perf_counter *counter)
+{
+ u64 prev, now;
+ s64 delta;
+
+ prev = atomic64_read(&counter->hw.prev_count);
+ now = get_cpu_migrations();
+
+ atomic64_set(&counter->hw.prev_count, now);
+
+ delta = now - prev;
+
+ atomic64_add(delta, &counter->count);
+}
+
+static void cpu_migrations_perf_counter_read(struct perf_counter *counter)
+{
+ cpu_migrations_perf_counter_update(counter);
+}
+
+static int cpu_migrations_perf_counter_enable(struct perf_counter *counter)
+{
+ /*
+ * se.nr_migrations is a per-task value already,
+ * so we dont have to clear it on switch-in.
+ */
+
+ return 0;
+}
+
+static void cpu_migrations_perf_counter_disable(struct perf_counter *counter)
+{
+ cpu_migrations_perf_counter_update(counter);
+}
+
+static const struct hw_perf_counter_ops perf_ops_cpu_migrations = {
+ .enable = cpu_migrations_perf_counter_enable,
+ .disable = cpu_migrations_perf_counter_disable,
+ .read = cpu_migrations_perf_counter_read,
+};
+
+static const struct hw_perf_counter_ops *
+sw_perf_counter_init(struct perf_counter *counter)
+{
+ const struct hw_perf_counter_ops *hw_ops = NULL;
+
+ switch (counter->hw_event.type) {
+ case PERF_COUNT_CPU_CLOCK:
+ hw_ops = &perf_ops_cpu_clock;
+ break;
+ case PERF_COUNT_TASK_CLOCK:
+ hw_ops = &perf_ops_task_clock;
+ break;
+ case PERF_COUNT_PAGE_FAULTS:
+ hw_ops = &perf_ops_page_faults;
+ break;
+ case PERF_COUNT_CONTEXT_SWITCHES:
+ hw_ops = &perf_ops_context_switches;
+ break;
+ case PERF_COUNT_CPU_MIGRATIONS:
+ hw_ops = &perf_ops_cpu_migrations;
+ break;
+ default:
+ break;
+ }
+ return hw_ops;
+}
+
+/*
+ * Allocate and initialize a counter structure
+ */
+static struct perf_counter *
+perf_counter_alloc(struct perf_counter_hw_event *hw_event,
+ int cpu,
+ struct perf_counter *group_leader,
+ gfp_t gfpflags)
+{
+ const struct hw_perf_counter_ops *hw_ops;
+ struct perf_counter *counter;
+
+ counter = kzalloc(sizeof(*counter), gfpflags);
+ if (!counter)
+ return NULL;
+
+ /*
+ * Single counters are their own group leaders, with an
+ * empty sibling list:
+ */
+ if (!group_leader)
+ group_leader = counter;
+
+ mutex_init(&counter->mutex);
+ INIT_LIST_HEAD(&counter->list_entry);
+ INIT_LIST_HEAD(&counter->sibling_list);
+ init_waitqueue_head(&counter->waitq);
+
+ counter->irqdata = &counter->data[0];
+ counter->usrdata = &counter->data[1];
+ counter->cpu = cpu;
+ counter->hw_event = *hw_event;
+ counter->wakeup_pending = 0;
+ counter->group_leader = group_leader;
+ counter->hw_ops = NULL;
+
+ counter->state = PERF_COUNTER_STATE_INACTIVE;
+ if (hw_event->disabled)
+ counter->state = PERF_COUNTER_STATE_OFF;
+
+ hw_ops = NULL;
+ if (!hw_event->raw && hw_event->type < 0)
+ hw_ops = sw_perf_counter_init(counter);
+ if (!hw_ops)
+ hw_ops = hw_perf_counter_init(counter);
+
+ if (!hw_ops) {
+ kfree(counter);
+ return NULL;
+ }
+ counter->hw_ops = hw_ops;
+
+ return counter;
+}
+
+/**
+ * sys_perf_task_open - open a performance counter, associate it to a task/cpu
+ *
+ * @hw_event_uptr: event type attributes for monitoring/sampling
+ * @pid: target pid
+ * @cpu: target cpu
+ * @group_fd: group leader counter fd
+ */
+asmlinkage int
+sys_perf_counter_open(struct perf_counter_hw_event *hw_event_uptr __user,
+ pid_t pid, int cpu, int group_fd)
+{
+ struct perf_counter *counter, *group_leader;
+ struct perf_counter_hw_event hw_event;
+ struct perf_counter_context *ctx;
+ struct file *counter_file = NULL;
+ struct file *group_file = NULL;
+ int fput_needed = 0;
+ int fput_needed2 = 0;
+ int ret;
+
+ if (copy_from_user(&hw_event, hw_event_uptr, sizeof(hw_event)) != 0)
+ return -EFAULT;
+
+ /*
+ * Get the target context (task or percpu):
+ */
+ ctx = find_get_context(pid, cpu);
+ if (IS_ERR(ctx))
+ return PTR_ERR(ctx);
+
+ /*
+ * Look up the group leader (we will attach this counter to it):
+ */
+ group_leader = NULL;
+ if (group_fd != -1) {
+ ret = -EINVAL;
+ group_file = fget_light(group_fd, &fput_needed);
+ if (!group_file)
+ goto err_put_context;
+ if (group_file->f_op != &perf_fops)
+ goto err_put_context;
+
+ group_leader = group_file->private_data;
+ /*
+ * Do not allow a recursive hierarchy (this new sibling
+ * becoming part of another group-sibling):
+ */
+ if (group_leader->group_leader != group_leader)
+ goto err_put_context;
+ /*
+ * Do not allow to attach to a group in a different
+ * task or CPU context:
+ */
+ if (group_leader->ctx != ctx)
+ goto err_put_context;
+ }
+
+ ret = -EINVAL;
+ counter = perf_counter_alloc(&hw_event, cpu, group_leader, GFP_KERNEL);
+ if (!counter)
+ goto err_put_context;
+
+ ret = anon_inode_getfd("[perf_counter]", &perf_fops, counter, 0);
+ if (ret < 0)
+ goto err_free_put_context;
+
+ counter_file = fget_light(ret, &fput_needed2);
+ if (!counter_file)
+ goto err_free_put_context;
+
+ counter->filp = counter_file;
+ perf_install_in_context(ctx, counter, cpu);
+
+ fput_light(counter_file, fput_needed2);
+
+out_fput:
+ fput_light(group_file, fput_needed);
+
+ return ret;
+
+err_free_put_context:
+ kfree(counter);
+
+err_put_context:
+ put_context(ctx);
+
+ goto out_fput;
+}
+
+/*
+ * Initialize the perf_counter context in a task_struct:
+ */
+static void
+__perf_counter_init_context(struct perf_counter_context *ctx,
+ struct task_struct *task)
+{
+ memset(ctx, 0, sizeof(*ctx));
+ spin_lock_init(&ctx->lock);
+ INIT_LIST_HEAD(&ctx->counter_list);
+ ctx->task = task;
+}
+
+/*
+ * inherit a counter from parent task to child task:
+ */
+static int
+inherit_counter(struct perf_counter *parent_counter,
+ struct task_struct *parent,
+ struct perf_counter_context *parent_ctx,
+ struct task_struct *child,
+ struct perf_counter_context *child_ctx)
+{
+ struct perf_counter *child_counter;
+
+ child_counter = perf_counter_alloc(&parent_counter->hw_event,
+ parent_counter->cpu, NULL,
+ GFP_ATOMIC);
+ if (!child_counter)
+ return -ENOMEM;
+
+ /*
+ * Link it up in the child's context:
+ */
+ child_counter->ctx = child_ctx;
+ child_counter->task = child;
+ list_add_counter(child_counter, child_ctx);
+ child_ctx->nr_counters++;
+
+ child_counter->parent = parent_counter;
+ /*
+ * inherit into child's child as well:
+ */
+ child_counter->hw_event.inherit = 1;
+
+ /*
+ * Get a reference to the parent filp - we will fput it
+ * when the child counter exits. This is safe to do because
+ * we are in the parent and we know that the filp still
+ * exists and has a nonzero count:
+ */
+ atomic_long_inc(&parent_counter->filp->f_count);
+
+ return 0;
+}
+
+static void
+__perf_counter_exit_task(struct task_struct *child,
+ struct perf_counter *child_counter,
+ struct perf_counter_context *child_ctx)
+{
+ struct perf_counter *parent_counter;
+ u64 parent_val, child_val;
+
+ /*
+ * If we do not self-reap then we have to wait for the
+ * child task to unschedule (it will happen for sure),
+ * so that its counter is at its final count. (This
+ * condition triggers rarely - child tasks usually get
+ * off their CPU before the parent has a chance to
+ * get this far into the reaping action)
+ */
+ if (child != current) {
+ wait_task_inactive(child, 0);
+ list_del_init(&child_counter->list_entry);
+ } else {
+ struct perf_cpu_context *cpuctx;
+ unsigned long flags;
+ u64 perf_flags;
+
+ /*
+ * Disable and unlink this counter.
+ *
+ * Be careful about zapping the list - IRQ/NMI context
+ * could still be processing it:
+ */
+ curr_rq_lock_irq_save(&flags);
+ perf_flags = hw_perf_save_disable();
+
+ cpuctx = &__get_cpu_var(perf_cpu_context);
+
+ if (child_counter->state == PERF_COUNTER_STATE_ACTIVE) {
+ child_counter->state = PERF_COUNTER_STATE_INACTIVE;
+ child_counter->hw_ops->disable(child_counter);
+ cpuctx->active_oncpu--;
+ child_ctx->nr_active--;
+ child_counter->oncpu = -1;
+ }
+
+ list_del_init(&child_counter->list_entry);
+
+ child_ctx->nr_counters--;
+
+ hw_perf_restore(perf_flags);
+ curr_rq_unlock_irq_restore(&flags);
+ }
+
+ parent_counter = child_counter->parent;
+ /*
+ * It can happen that parent exits first, and has counters
+ * that are still around due to the child reference. These
+ * counters need to be zapped - but otherwise linger.
+ */
+ if (!parent_counter)
+ return;
+
+ parent_val = atomic64_read(&parent_counter->count);
+ child_val = atomic64_read(&child_counter->count);
+
+ /*
+ * Add back the child's count to the parent's count:
+ */
+ atomic64_add(child_val, &parent_counter->count);
+
+ fput(parent_counter->filp);
+
+ kfree(child_counter);
+}
+
+/*
+ * When a child task exist, feed back counter values to parent counters.
+ *
+ * Note: we are running in child context, but the PID is not hashed
+ * anymore so new counters will not be added.
+ */
+void perf_counter_exit_task(struct task_struct *child)
+{
+ struct perf_counter *child_counter, *tmp;
+ struct perf_counter_context *child_ctx;
+
+ child_ctx = &child->perf_counter_ctx;
+
+ if (likely(!child_ctx->nr_counters))
+ return;
+
+ list_for_each_entry_safe(child_counter, tmp, &child_ctx->counter_list,
+ list_entry)
+ __perf_counter_exit_task(child, child_counter, child_ctx);
+}
+
+/*
+ * Initialize the perf_counter context in task_struct
+ */
+void perf_counter_init_task(struct task_struct *child)
+{
+ struct perf_counter_context *child_ctx, *parent_ctx;
+ struct perf_counter *counter, *parent_counter;
+ struct task_struct *parent = current;
+ unsigned long flags;
+
+ child_ctx = &child->perf_counter_ctx;
+ parent_ctx = &parent->perf_counter_ctx;
+
+ __perf_counter_init_context(child_ctx, child);
+
+ /*
+ * This is executed from the parent task context, so inherit
+ * counters that have been marked for cloning:
+ */
+
+ if (likely(!parent_ctx->nr_counters))
+ return;
+
+ /*
+ * Lock the parent list. No need to lock the child - not PID
+ * hashed yet and not running, so nobody can access it.
+ */
+ spin_lock_irqsave(&parent_ctx->lock, flags);
+
+ /*
+ * We dont have to disable NMIs - we are only looking at
+ * the list, not manipulating it:
+ */
+ list_for_each_entry(counter, &parent_ctx->counter_list, list_entry) {
+ if (!counter->hw_event.inherit || counter->group_leader != counter)
+ continue;
+
+ /*
+ * Instead of creating recursive hierarchies of counters,
+ * we link inheritd counters back to the original parent,
+ * which has a filp for sure, which we use as the reference
+ * count:
+ */
+ parent_counter = counter;
+ if (counter->parent)
+ parent_counter = counter->parent;
+
+ if (inherit_counter(parent_counter, parent,
+ parent_ctx, child, child_ctx))
+ break;
+ }
+
+ spin_unlock_irqrestore(&parent_ctx->lock, flags);
+}
+
+static void __cpuinit perf_counter_init_cpu(int cpu)
+{
+ struct perf_cpu_context *cpuctx;
+
+ cpuctx = &per_cpu(perf_cpu_context, cpu);
+ __perf_counter_init_context(&cpuctx->ctx, NULL);
+
+ mutex_lock(&perf_resource_mutex);
+ cpuctx->max_pertask = perf_max_counters - perf_reserved_percpu;
+ mutex_unlock(&perf_resource_mutex);
+
+ hw_perf_counter_setup();
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+static void __perf_counter_exit_cpu(void *info)
+{
+ struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
+ struct perf_counter_context *ctx = &cpuctx->ctx;
+ struct perf_counter *counter, *tmp;
+
+ list_for_each_entry_safe(counter, tmp, &ctx->counter_list, list_entry)
+ __perf_counter_remove_from_context(counter);
+
+}
+static void perf_counter_exit_cpu(int cpu)
+{
+ smp_call_function_single(cpu, __perf_counter_exit_cpu, NULL, 1);
+}
+#else
+static inline void perf_counter_exit_cpu(int cpu) { }
+#endif
+
+static int __cpuinit
+perf_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu)
+{
+ unsigned int cpu = (long)hcpu;
+
+ switch (action) {
+
+ case CPU_UP_PREPARE:
+ case CPU_UP_PREPARE_FROZEN:
+ perf_counter_init_cpu(cpu);
+ break;
+
+ case CPU_DOWN_PREPARE:
+ case CPU_DOWN_PREPARE_FROZEN:
+ perf_counter_exit_cpu(cpu);
+ break;
+
+ default:
+ break;
+ }
+
+ return NOTIFY_OK;
+}
+
+static struct notifier_block __cpuinitdata perf_cpu_nb = {
+ .notifier_call = perf_cpu_notify,
+};
+
+static int __init perf_counter_init(void)
+{
+ perf_cpu_notify(&perf_cpu_nb, (unsigned long)CPU_UP_PREPARE,
+ (void *)(long)smp_processor_id());
+ register_cpu_notifier(&perf_cpu_nb);
+
+ return 0;
+}
+early_initcall(perf_counter_init);
+
+static ssize_t perf_show_reserve_percpu(struct sysdev_class *class, char *buf)
+{
+ return sprintf(buf, "%d\n", perf_reserved_percpu);
+}
+
+static ssize_t
+perf_set_reserve_percpu(struct sysdev_class *class,
+ const char *buf,
+ size_t count)
+{
+ struct perf_cpu_context *cpuctx;
+ unsigned long val;
+ int err, cpu, mpt;
+
+ err = strict_strtoul(buf, 10, &val);
+ if (err)
+ return err;
+ if (val > perf_max_counters)
+ return -EINVAL;
+
+ mutex_lock(&perf_resource_mutex);
+ perf_reserved_percpu = val;
+ for_each_online_cpu(cpu) {
+ cpuctx = &per_cpu(perf_cpu_context, cpu);
+ spin_lock_irq(&cpuctx->ctx.lock);
+ mpt = min(perf_max_counters - cpuctx->ctx.nr_counters,
+ perf_max_counters - perf_reserved_percpu);
+ cpuctx->max_pertask = mpt;
+ spin_unlock_irq(&cpuctx->ctx.lock);
+ }
+ mutex_unlock(&perf_resource_mutex);
+
+ return count;
+}
+
+static ssize_t perf_show_overcommit(struct sysdev_class *class, char *buf)
+{
+ return sprintf(buf, "%d\n", perf_overcommit);
+}
+
+static ssize_t
+perf_set_overcommit(struct sysdev_class *class, const char *buf, size_t count)
+{
+ unsigned long val;
+ int err;
+
+ err = strict_strtoul(buf, 10, &val);
+ if (err)
+ return err;
+ if (val > 1)
+ return -EINVAL;
+
+ mutex_lock(&perf_resource_mutex);
+ perf_overcommit = val;
+ mutex_unlock(&perf_resource_mutex);
+
+ return count;
+}
+
+static SYSDEV_CLASS_ATTR(
+ reserve_percpu,
+ 0644,
+ perf_show_reserve_percpu,
+ perf_set_reserve_percpu
+ );
+
+static SYSDEV_CLASS_ATTR(
+ overcommit,
+ 0644,
+ perf_show_overcommit,
+ perf_set_overcommit
+ );
+
+static struct attribute *perfclass_attrs[] = {
+ &attr_reserve_percpu.attr,
+ &attr_overcommit.attr,
+ NULL
+};
+
+static struct attribute_group perfclass_attr_group = {
+ .attrs = perfclass_attrs,
+ .name = "perf_counters",
+};
+
+static int __init perf_counter_sysfs_init(void)
+{
+ return sysfs_create_group(&cpu_sysdev_class.kset.kobj,
+ &perfclass_attr_group);
+}
+device_initcall(perf_counter_sysfs_init);
#define task_rq(p) cpu_rq(task_cpu(p))
#define cpu_curr(cpu) (cpu_rq(cpu)->curr)
-static inline void update_rq_clock(struct rq *rq)
+inline void update_rq_clock(struct rq *rq)
{
rq->clock = sched_clock_cpu(cpu_of(rq));
}
}
}
+void curr_rq_lock_irq_save(unsigned long *flags)
+ __acquires(rq->lock)
+{
+ struct rq *rq;
+
+ local_irq_save(*flags);
+ rq = cpu_rq(smp_processor_id());
+ spin_lock(&rq->lock);
+}
+
+void curr_rq_unlock_irq_restore(unsigned long *flags)
+ __releases(rq->lock)
+{
+ struct rq *rq;
+
+ rq = cpu_rq(smp_processor_id());
+ spin_unlock(&rq->lock);
+ local_irq_restore(*flags);
+}
+
void task_rq_unlock_wait(struct task_struct *p)
{
struct rq *rq = task_rq(p);
p->se.sleep_start -= clock_offset;
if (p->se.block_start)
p->se.block_start -= clock_offset;
+#endif
if (old_cpu != new_cpu) {
- schedstat_inc(p, se.nr_migrations);
+ p->se.nr_migrations++;
+#ifdef CONFIG_SCHEDSTATS
if (task_hot(p, old_rq->clock, NULL))
schedstat_inc(p, se.nr_forced2_migrations);
- }
#endif
+ }
p->se.vruntime -= old_cfsrq->min_vruntime -
new_cfsrq->min_vruntime;
#endif /* CONFIG_SMP */
+/**
+ * task_oncpu_function_call - call a function on the cpu on which a task runs
+ * @p: the task to evaluate
+ * @func: the function to be called
+ * @info: the function call argument
+ *
+ * Calls the function @func when the task is currently running. This might
+ * be on the current CPU, which just calls the function directly
+ */
+void task_oncpu_function_call(struct task_struct *p,
+ void (*func) (void *info), void *info)
+{
+ int cpu;
+
+ preempt_disable();
+ cpu = task_cpu(p);
+ if (task_curr(p))
+ smp_call_function_single(cpu, func, info, 1);
+ preempt_enable();
+}
+
/***
* try_to_wake_up - wake up a thread
* @p: the to-be-woken-up thread
p->se.exec_start = 0;
p->se.sum_exec_runtime = 0;
p->se.prev_sum_exec_runtime = 0;
+ p->se.nr_migrations = 0;
p->se.last_wakeup = 0;
p->se.avg_overlap = 0;
*/
prev_state = prev->state;
finish_arch_switch(prev);
+ perf_counter_task_sched_in(current, cpu_of(rq));
finish_lock_switch(rq, prev);
#ifdef CONFIG_SMP
if (current->sched_class->post_schedule)
EXPORT_PER_CPU_SYMBOL(kstat);
+/*
+ * Return any ns on the sched_clock that have not yet been banked in
+ * @p in case that task is currently running.
+ */
+unsigned long long __task_delta_exec(struct task_struct *p, int update)
+{
+ s64 delta_exec;
+ struct rq *rq;
+
+ rq = task_rq(p);
+ WARN_ON_ONCE(!runqueue_is_locked());
+ WARN_ON_ONCE(!task_current(rq, p));
+
+ if (update)
+ update_rq_clock(rq);
+
+ delta_exec = rq->clock - p->se.exec_start;
+
+ WARN_ON_ONCE(delta_exec < 0);
+
+ return delta_exec;
+}
+
/*
* Return any ns on the sched_clock that have not yet been banked in
* @p in case that task is currently running.
update_rq_clock(rq);
update_cpu_load(rq);
curr->sched_class->task_tick(rq, curr, 0);
+ perf_counter_task_tick(curr, cpu);
spin_unlock(&rq->lock);
#ifdef CONFIG_SMP
if (likely(prev != next)) {
sched_info_switch(prev, next);
+ perf_counter_task_sched_out(prev, cpu);
rq->nr_switches++;
rq->curr = next;
#include <linux/prctl.h>
#include <linux/highuid.h>
#include <linux/fs.h>
+#include <linux/perf_counter.h>
#include <linux/resource.h>
#include <linux/kernel.h>
#include <linux/kexec.h>
case PR_SET_TSC:
error = SET_TSC_CTL(arg2);
break;
+ case PR_TASK_PERF_COUNTERS_DISABLE:
+ error = perf_counter_task_disable();
+ break;
+ case PR_TASK_PERF_COUNTERS_ENABLE:
+ error = perf_counter_task_enable();
+ break;
case PR_GET_TIMERSLACK:
error = current->timer_slack_ns;
break;
cond_syscall(compat_sys_timerfd_gettime);
cond_syscall(sys_eventfd);
cond_syscall(sys_eventfd2);
+
+/* performance counters: */
+cond_syscall(sys_perf_counter_open);
projects / linux-block.git / commitdiff