#include <linux/pid.h>
#include <linux/percpu.h>
#include <linux/topology.h>
-#include <linux/proportions.h>
#include <linux/seccomp.h>
#include <linux/rcupdate.h>
#include <linux/rculist.h>
extern void calc_global_load(unsigned long ticks);
#if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
-extern void update_cpu_load_nohz(int active);
+extern void cpu_load_update_nohz_start(void);
+extern void cpu_load_update_nohz_stop(void);
#else
-static inline void update_cpu_load_nohz(int active) { }
+static inline void cpu_load_update_nohz_start(void) { }
+static inline void cpu_load_update_nohz_stop(void) { }
#endif
extern void dump_cpu_task(int cpu);
extern void trap_init(void);
extern void update_process_times(int user);
extern void scheduler_tick(void);
+extern int sched_cpu_starting(unsigned int cpu);
+extern int sched_cpu_activate(unsigned int cpu);
+extern int sched_cpu_deactivate(unsigned int cpu);
+
+#ifdef CONFIG_HOTPLUG_CPU
+extern int sched_cpu_dying(unsigned int cpu);
+#else
+# define sched_cpu_dying NULL
+#endif
extern void sched_show_task(struct task_struct *p);
CPU_MAX_IDLE_TYPES
};
+/*
+ * Integer metrics need fixed point arithmetic, e.g., sched/fair
+ * has a few: load, load_avg, util_avg, freq, and capacity.
+ *
+ * We define a basic fixed point arithmetic range, and then formalize
+ * all these metrics based on that basic range.
+ */
+# define SCHED_FIXEDPOINT_SHIFT 10
+# define SCHED_FIXEDPOINT_SCALE (1L << SCHED_FIXEDPOINT_SHIFT)
+
/*
* Increase resolution of cpu_capacity calculations
*/
-#define SCHED_CAPACITY_SHIFT 10
+#define SCHED_CAPACITY_SHIFT SCHED_FIXEDPOINT_SHIFT
#define SCHED_CAPACITY_SCALE (1L << SCHED_CAPACITY_SHIFT)
/*
};
/*
- * The load_avg/util_avg accumulates an infinite geometric series.
- * 1) load_avg factors frequency scaling into the amount of time that a
- * sched_entity is runnable on a rq into its weight. For cfs_rq, it is the
- * aggregated such weights of all runnable and blocked sched_entities.
- * 2) util_avg factors frequency and cpu scaling into the amount of time
- * that a sched_entity is running on a CPU, in the range [0..SCHED_LOAD_SCALE].
- * For cfs_rq, it is the aggregated such times of all runnable and
+ * The load_avg/util_avg accumulates an infinite geometric series
+ * (see __update_load_avg() in kernel/sched/fair.c).
+ *
+ * [load_avg definition]
+ *
+ * load_avg = runnable% * scale_load_down(load)
+ *
+ * where runnable% is the time ratio that a sched_entity is runnable.
+ * For cfs_rq, it is the aggregated load_avg of all runnable and
* blocked sched_entities.
- * The 64 bit load_sum can:
- * 1) for cfs_rq, afford 4353082796 (=2^64/47742/88761) entities with
- * the highest weight (=88761) always runnable, we should not overflow
- * 2) for entity, support any load.weight always runnable
+ *
+ * load_avg may also take frequency scaling into account:
+ *
+ * load_avg = runnable% * scale_load_down(load) * freq%
+ *
+ * where freq% is the CPU frequency normalized to the highest frequency.
+ *
+ * [util_avg definition]
+ *
+ * util_avg = running% * SCHED_CAPACITY_SCALE
+ *
+ * where running% is the time ratio that a sched_entity is running on
+ * a CPU. For cfs_rq, it is the aggregated util_avg of all runnable
+ * and blocked sched_entities.
+ *
+ * util_avg may also factor frequency scaling and CPU capacity scaling:
+ *
+ * util_avg = running% * SCHED_CAPACITY_SCALE * freq% * capacity%
+ *
+ * where freq% is the same as above, and capacity% is the CPU capacity
+ * normalized to the greatest capacity (due to uarch differences, etc).
+ *
+ * N.B., the above ratios (runnable%, running%, freq%, and capacity%)
+ * themselves are in the range of [0, 1]. To do fixed point arithmetics,
+ * we therefore scale them to as large a range as necessary. This is for
+ * example reflected by util_avg's SCHED_CAPACITY_SCALE.
+ *
+ * [Overflow issue]
+ *
+ * The 64-bit load_sum can have 4353082796 (=2^64/47742/88761) entities
+ * with the highest load (=88761), always runnable on a single cfs_rq,
+ * and should not overflow as the number already hits PID_MAX_LIMIT.
+ *
+ * For all other cases (including 32-bit kernels), struct load_weight's
+ * weight will overflow first before we do, because:
+ *
+ * Max(load_avg) <= Max(load.weight)
+ *
+ * Then it is the load_weight's responsibility to consider overflow
+ * issues.
*/
struct sched_avg {
u64 last_update_time, load_sum;
unsigned long sas_ss_sp;
size_t sas_ss_size;
+ unsigned sas_ss_flags;
struct callback_head *task_works;
/* Future-safe accessor for struct task_struct's cpus_allowed. */
#define tsk_cpus_allowed(tsk) (&(tsk)->cpus_allowed)
+static inline int tsk_nr_cpus_allowed(struct task_struct *p)
+{
+ return p->nr_cpus_allowed;
+}
+
#define TNF_MIGRATED 0x01
#define TNF_NO_GROUP 0x02
#define TNF_SHARED 0x04
/*
* See the comment in kernel/sched/clock.c
*/
-extern u64 cpu_clock(int cpu);
-extern u64 local_clock(void);
extern u64 running_clock(void);
extern u64 sched_clock_cpu(int cpu);
static inline void sched_clock_idle_wakeup_event(u64 delta_ns)
{
}
+
+static inline u64 cpu_clock(int cpu)
+{
+ return sched_clock();
+}
+
+static inline u64 local_clock(void)
+{
+ return sched_clock();
+}
#else
/*
* Architectures can set this to 1 if they have specified
extern void sched_clock_tick(void);
extern void sched_clock_idle_sleep_event(void);
extern void sched_clock_idle_wakeup_event(u64 delta_ns);
+
+/*
+ * As outlined in clock.c, provides a fast, high resolution, nanosecond
+ * time source that is monotonic per cpu argument and has bounded drift
+ * between cpus.
+ *
+ * ######################### BIG FAT WARNING ##########################
+ * # when comparing cpu_clock(i) to cpu_clock(j) for i != j, time can #
+ * # go backwards !! #
+ * ####################################################################
+ */
+static inline u64 cpu_clock(int cpu)
+{
+ return sched_clock_cpu(cpu);
+}
+
+static inline u64 local_clock(void)
+{
+ return sched_clock_cpu(raw_smp_processor_id());
+}
#endif
#ifdef CONFIG_IRQ_TIME_ACCOUNTING
*/
static inline int on_sig_stack(unsigned long sp)
{
+ /*
+ * If the signal stack is SS_AUTODISARM then, by construction, we
+ * can't be on the signal stack unless user code deliberately set
+ * SS_AUTODISARM when we were already on it.
+ *
+ * This improves reliability: if user state gets corrupted such that
+ * the stack pointer points very close to the end of the signal stack,
+ * then this check will enable the signal to be handled anyway.
+ */
+ if (current->sas_ss_flags & SS_AUTODISARM)
+ return 0;
+
#ifdef CONFIG_STACK_GROWSUP
return sp >= current->sas_ss_sp &&
sp - current->sas_ss_sp < current->sas_ss_size;
return on_sig_stack(sp) ? SS_ONSTACK : 0;
}
+static inline void sas_ss_reset(struct task_struct *p)
+{
+ p->sas_ss_sp = 0;
+ p->sas_ss_size = 0;
+ p->sas_ss_flags = SS_DISABLE;
+}
+
static inline unsigned long sigsp(unsigned long sp, struct ksignal *ksig)
{
if (unlikely((ksig->ka.sa.sa_flags & SA_ONSTACK)) && ! sas_ss_flags(sp))
projects / linux-2.6-block.git / blobdiff