summaryrefslogtreecommitdiff
path: root/include
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2016-03-15 05:44:38 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2016-03-15 05:44:38 +0300
commite23604edac2a7be6a8808a5d13fac6b9df4eb9a8 (patch)
tree7a7fa87796fb1dc6dd355675816e2e59546d4edd /include
parentd4e796152a049f6a675f8b6dcf7080a9d80014e5 (diff)
parent1f25184656a00a59e3a953189070d42a749f6aee (diff)
downloadlinux-e23604edac2a7be6a8808a5d13fac6b9df4eb9a8.tar.xz
Merge branch 'timers-nohz-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull NOHZ updates from Ingo Molnar: "NOHZ enhancements, by Frederic Weisbecker, which reorganizes/refactors the NOHZ 'can the tick be stopped?' infrastructure and related code to be data driven, and harmonizes the naming and handling of all the various properties" [ This makes the ugly "fetch_or()" macro that the scheduler used internally a new generic helper, and does a bad job at it. I'm pulling it, but I've asked Ingo and Frederic to get this fixed up ] * 'timers-nohz-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched-clock: Migrate to use new tick dependency mask model posix-cpu-timers: Migrate to use new tick dependency mask model sched: Migrate sched to use new tick dependency mask model sched: Account rr tasks perf: Migrate perf to use new tick dependency mask model nohz: Use enum code for tick stop failure tracing message nohz: New tick dependency mask nohz: Implement wide kick on top of irq work atomic: Export fetch_or()
Diffstat (limited to 'include')
-rw-r--r--include/linux/atomic.h21
-rw-r--r--include/linux/perf_event.h6
-rw-r--r--include/linux/posix-timers.h3
-rw-r--r--include/linux/sched.h11
-rw-r--r--include/linux/tick.h97
-rw-r--r--include/trace/events/timer.h36
6 files changed, 153 insertions, 21 deletions
diff --git a/include/linux/atomic.h b/include/linux/atomic.h
index 301de78d65f7..6c502cb13c95 100644
--- a/include/linux/atomic.h
+++ b/include/linux/atomic.h
@@ -548,6 +548,27 @@ static inline int atomic_dec_if_positive(atomic_t *v)
}
#endif
+/**
+ * fetch_or - perform *ptr |= mask and return old value of *ptr
+ * @ptr: pointer to value
+ * @mask: mask to OR on the value
+ *
+ * cmpxchg based fetch_or, macro so it works for different integer types
+ */
+#ifndef fetch_or
+#define fetch_or(ptr, mask) \
+({ typeof(*(ptr)) __old, __val = *(ptr); \
+ for (;;) { \
+ __old = cmpxchg((ptr), __val, __val | (mask)); \
+ if (__old == __val) \
+ break; \
+ __val = __old; \
+ } \
+ __old; \
+})
+#endif
+
+
#ifdef CONFIG_GENERIC_ATOMIC64
#include <asm-generic/atomic64.h>
#endif
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index a9d8cab18b00..79ec7bbf0155 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -1110,12 +1110,6 @@ static inline void perf_event_task_tick(void) { }
static inline int perf_event_release_kernel(struct perf_event *event) { return 0; }
#endif
-#if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_NO_HZ_FULL)
-extern bool perf_event_can_stop_tick(void);
-#else
-static inline bool perf_event_can_stop_tick(void) { return true; }
-#endif
-
#if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_CPU_SUP_INTEL)
extern void perf_restore_debug_store(void);
#else
diff --git a/include/linux/posix-timers.h b/include/linux/posix-timers.h
index 907f3fd191ac..62d44c176071 100644
--- a/include/linux/posix-timers.h
+++ b/include/linux/posix-timers.h
@@ -128,9 +128,6 @@ void posix_cpu_timer_schedule(struct k_itimer *timer);
void run_posix_cpu_timers(struct task_struct *task);
void posix_cpu_timers_exit(struct task_struct *task);
void posix_cpu_timers_exit_group(struct task_struct *task);
-
-bool posix_cpu_timers_can_stop_tick(struct task_struct *tsk);
-
void set_process_cpu_timer(struct task_struct *task, unsigned int clock_idx,
cputime_t *newval, cputime_t *oldval);
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 838a89a78332..c617ea12c6b7 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -717,6 +717,10 @@ struct signal_struct {
/* Earliest-expiration cache. */
struct task_cputime cputime_expires;
+#ifdef CONFIG_NO_HZ_FULL
+ unsigned long tick_dep_mask;
+#endif
+
struct list_head cpu_timers[3];
struct pid *tty_old_pgrp;
@@ -1542,6 +1546,10 @@ struct task_struct {
VTIME_SYS,
} vtime_snap_whence;
#endif
+
+#ifdef CONFIG_NO_HZ_FULL
+ unsigned long tick_dep_mask;
+#endif
unsigned long nvcsw, nivcsw; /* context switch counts */
u64 start_time; /* monotonic time in nsec */
u64 real_start_time; /* boot based time in nsec */
@@ -2356,10 +2364,7 @@ static inline void wake_up_nohz_cpu(int cpu) { }
#endif
#ifdef CONFIG_NO_HZ_FULL
-extern bool sched_can_stop_tick(void);
extern u64 scheduler_tick_max_deferment(void);
-#else
-static inline bool sched_can_stop_tick(void) { return false; }
#endif
#ifdef CONFIG_SCHED_AUTOGROUP
diff --git a/include/linux/tick.h b/include/linux/tick.h
index 97fd4e543846..21f73649a4dc 100644
--- a/include/linux/tick.h
+++ b/include/linux/tick.h
@@ -97,6 +97,19 @@ static inline void tick_broadcast_exit(void)
tick_broadcast_oneshot_control(TICK_BROADCAST_EXIT);
}
+enum tick_dep_bits {
+ TICK_DEP_BIT_POSIX_TIMER = 0,
+ TICK_DEP_BIT_PERF_EVENTS = 1,
+ TICK_DEP_BIT_SCHED = 2,
+ TICK_DEP_BIT_CLOCK_UNSTABLE = 3
+};
+
+#define TICK_DEP_MASK_NONE 0
+#define TICK_DEP_MASK_POSIX_TIMER (1 << TICK_DEP_BIT_POSIX_TIMER)
+#define TICK_DEP_MASK_PERF_EVENTS (1 << TICK_DEP_BIT_PERF_EVENTS)
+#define TICK_DEP_MASK_SCHED (1 << TICK_DEP_BIT_SCHED)
+#define TICK_DEP_MASK_CLOCK_UNSTABLE (1 << TICK_DEP_BIT_CLOCK_UNSTABLE)
+
#ifdef CONFIG_NO_HZ_COMMON
extern int tick_nohz_enabled;
extern int tick_nohz_tick_stopped(void);
@@ -154,9 +167,73 @@ static inline int housekeeping_any_cpu(void)
return cpumask_any_and(housekeeping_mask, cpu_online_mask);
}
-extern void tick_nohz_full_kick(void);
+extern void tick_nohz_dep_set(enum tick_dep_bits bit);
+extern void tick_nohz_dep_clear(enum tick_dep_bits bit);
+extern void tick_nohz_dep_set_cpu(int cpu, enum tick_dep_bits bit);
+extern void tick_nohz_dep_clear_cpu(int cpu, enum tick_dep_bits bit);
+extern void tick_nohz_dep_set_task(struct task_struct *tsk,
+ enum tick_dep_bits bit);
+extern void tick_nohz_dep_clear_task(struct task_struct *tsk,
+ enum tick_dep_bits bit);
+extern void tick_nohz_dep_set_signal(struct signal_struct *signal,
+ enum tick_dep_bits bit);
+extern void tick_nohz_dep_clear_signal(struct signal_struct *signal,
+ enum tick_dep_bits bit);
+
+/*
+ * The below are tick_nohz_[set,clear]_dep() wrappers that optimize off-cases
+ * on top of static keys.
+ */
+static inline void tick_dep_set(enum tick_dep_bits bit)
+{
+ if (tick_nohz_full_enabled())
+ tick_nohz_dep_set(bit);
+}
+
+static inline void tick_dep_clear(enum tick_dep_bits bit)
+{
+ if (tick_nohz_full_enabled())
+ tick_nohz_dep_clear(bit);
+}
+
+static inline void tick_dep_set_cpu(int cpu, enum tick_dep_bits bit)
+{
+ if (tick_nohz_full_cpu(cpu))
+ tick_nohz_dep_set_cpu(cpu, bit);
+}
+
+static inline void tick_dep_clear_cpu(int cpu, enum tick_dep_bits bit)
+{
+ if (tick_nohz_full_cpu(cpu))
+ tick_nohz_dep_clear_cpu(cpu, bit);
+}
+
+static inline void tick_dep_set_task(struct task_struct *tsk,
+ enum tick_dep_bits bit)
+{
+ if (tick_nohz_full_enabled())
+ tick_nohz_dep_set_task(tsk, bit);
+}
+static inline void tick_dep_clear_task(struct task_struct *tsk,
+ enum tick_dep_bits bit)
+{
+ if (tick_nohz_full_enabled())
+ tick_nohz_dep_clear_task(tsk, bit);
+}
+static inline void tick_dep_set_signal(struct signal_struct *signal,
+ enum tick_dep_bits bit)
+{
+ if (tick_nohz_full_enabled())
+ tick_nohz_dep_set_signal(signal, bit);
+}
+static inline void tick_dep_clear_signal(struct signal_struct *signal,
+ enum tick_dep_bits bit)
+{
+ if (tick_nohz_full_enabled())
+ tick_nohz_dep_clear_signal(signal, bit);
+}
+
extern void tick_nohz_full_kick_cpu(int cpu);
-extern void tick_nohz_full_kick_all(void);
extern void __tick_nohz_task_switch(void);
#else
static inline int housekeeping_any_cpu(void)
@@ -166,9 +243,21 @@ static inline int housekeeping_any_cpu(void)
static inline bool tick_nohz_full_enabled(void) { return false; }
static inline bool tick_nohz_full_cpu(int cpu) { return false; }
static inline void tick_nohz_full_add_cpus_to(struct cpumask *mask) { }
+
+static inline void tick_dep_set(enum tick_dep_bits bit) { }
+static inline void tick_dep_clear(enum tick_dep_bits bit) { }
+static inline void tick_dep_set_cpu(int cpu, enum tick_dep_bits bit) { }
+static inline void tick_dep_clear_cpu(int cpu, enum tick_dep_bits bit) { }
+static inline void tick_dep_set_task(struct task_struct *tsk,
+ enum tick_dep_bits bit) { }
+static inline void tick_dep_clear_task(struct task_struct *tsk,
+ enum tick_dep_bits bit) { }
+static inline void tick_dep_set_signal(struct signal_struct *signal,
+ enum tick_dep_bits bit) { }
+static inline void tick_dep_clear_signal(struct signal_struct *signal,
+ enum tick_dep_bits bit) { }
+
static inline void tick_nohz_full_kick_cpu(int cpu) { }
-static inline void tick_nohz_full_kick(void) { }
-static inline void tick_nohz_full_kick_all(void) { }
static inline void __tick_nohz_task_switch(void) { }
#endif
diff --git a/include/trace/events/timer.h b/include/trace/events/timer.h
index 073b9ac245ba..51440131d337 100644
--- a/include/trace/events/timer.h
+++ b/include/trace/events/timer.h
@@ -328,23 +328,49 @@ TRACE_EVENT(itimer_expire,
);
#ifdef CONFIG_NO_HZ_COMMON
+
+#define TICK_DEP_NAMES \
+ tick_dep_name(NONE) \
+ tick_dep_name(POSIX_TIMER) \
+ tick_dep_name(PERF_EVENTS) \
+ tick_dep_name(SCHED) \
+ tick_dep_name_end(CLOCK_UNSTABLE)
+
+#undef tick_dep_name
+#undef tick_dep_name_end
+
+#define tick_dep_name(sdep) TRACE_DEFINE_ENUM(TICK_DEP_MASK_##sdep);
+#define tick_dep_name_end(sdep) TRACE_DEFINE_ENUM(TICK_DEP_MASK_##sdep);
+
+TICK_DEP_NAMES
+
+#undef tick_dep_name
+#undef tick_dep_name_end
+
+#define tick_dep_name(sdep) { TICK_DEP_MASK_##sdep, #sdep },
+#define tick_dep_name_end(sdep) { TICK_DEP_MASK_##sdep, #sdep }
+
+#define show_tick_dep_name(val) \
+ __print_symbolic(val, TICK_DEP_NAMES)
+
TRACE_EVENT(tick_stop,
- TP_PROTO(int success, char *error_msg),
+ TP_PROTO(int success, int dependency),
- TP_ARGS(success, error_msg),
+ TP_ARGS(success, dependency),
TP_STRUCT__entry(
__field( int , success )
- __string( msg, error_msg )
+ __field( int , dependency )
),
TP_fast_assign(
__entry->success = success;
- __assign_str(msg, error_msg);
+ __entry->dependency = dependency;
),
- TP_printk("success=%s msg=%s", __entry->success ? "yes" : "no", __get_str(msg))
+ TP_printk("success=%d dependency=%s", __entry->success, \
+ show_tick_dep_name(__entry->dependency))
);
#endif