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| author | Ingo Molnar <mingo@kernel.org> | 2013-04-24 09:39:24 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2013-04-24 09:39:24 +0200 |
| commit | 447a34a2b77da949ea0870c2bef9b501d2d4c4ab (patch) | |
| tree | ef6bcfbcd99ddbe366f1de94b6aa75da7c6ea55f /kernel/time | |
| parent | bf967be396d0c6a52668921e7223856349d04b5e (diff) | |
| parent | cb41a29076e9f95547da46578d5c8804f7b8845d (diff) | |
| download | lwn-447a34a2b77da949ea0870c2bef9b501d2d4c4ab.tar.gz lwn-447a34a2b77da949ea0870c2bef9b501d2d4c4ab.zip | |
Merge branch 'timers/nohz-help-testing' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks into timers/nohz
Pull full dynticks helpers from Frederic Weisbecker:
- handy tracepoints that allow dynticks analysis,
to answer "why does my tick not stop??" questions
- select CONFIG_RCU_NOCB_ALL
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/time')
| -rw-r--r-- | kernel/time/Kconfig | 1 | ||||
| -rw-r--r-- | kernel/time/tick-sched.c | 19 |
2 files changed, 16 insertions, 4 deletions
diff --git a/kernel/time/Kconfig b/kernel/time/Kconfig index f6a792ab4983..e1ac129b01c9 100644 --- a/kernel/time/Kconfig +++ b/kernel/time/Kconfig @@ -110,6 +110,7 @@ config NO_HZ_FULL select NO_HZ_COMMON select RCU_USER_QS select RCU_NOCB_CPU + select RCU_NOCB_CPU_ALL select CONTEXT_TRACKING_FORCE select IRQ_WORK help diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 12a900dbb819..85e05ab98253 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -28,6 +28,8 @@ #include "tick-internal.h" +#include <trace/events/timer.h> + /* * Per cpu nohz control structure */ @@ -153,14 +155,20 @@ static bool can_stop_full_tick(void) { WARN_ON_ONCE(!irqs_disabled()); - if (!sched_can_stop_tick()) + if (!sched_can_stop_tick()) { + trace_tick_stop(0, "more than 1 task in runqueue\n"); return false; + } - if (!posix_cpu_timers_can_stop_tick(current)) + if (!posix_cpu_timers_can_stop_tick(current)) { + trace_tick_stop(0, "posix timers running\n"); return false; + } - if (!perf_event_can_stop_tick()) + if (!perf_event_can_stop_tick()) { + trace_tick_stop(0, "perf events running\n"); return false; + } /* sched_clock_tick() needs us? */ #ifdef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK @@ -168,8 +176,10 @@ static bool can_stop_full_tick(void) * TODO: kick full dynticks CPUs when * sched_clock_stable is set. */ - if (!sched_clock_stable) + if (!sched_clock_stable) { + trace_tick_stop(0, "unstable sched clock\n"); return false; + } #endif return true; @@ -631,6 +641,7 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts, ts->last_tick = hrtimer_get_expires(&ts->sched_timer); ts->tick_stopped = 1; + trace_tick_stop(1, " "); } /* |