diff options
| author | Carsten Emde <C.Emde@osadl.org> | 2011-07-19 13:03:41 (GMT) |
|---|---|---|
| committer | Scott Wood <scottwood@freescale.com> | 2014-04-10 00:18:45 (GMT) |
| commit | ca629a5e1742e029d594ce89a3962bd4d1ce39e4 (patch) | |
| tree | 8ba9fff2cd421f91f577d79a99ba64145e0d4f16 /kernel/hrtimer.c | |
| parent | 9e2dba555698b6334ebef35d6803d6e2eab65810 (diff) | |
| download | linux-fsl-qoriq-ca629a5e1742e029d594ce89a3962bd4d1ce39e4.tar.xz | |
latency-hist.patch
This patch provides a recording mechanism to store data of potential
sources of system latencies. The recordings separately determine the
latency caused by a delayed timer expiration, by a delayed wakeup of the
related user space program and by the sum of both. The histograms can be
enabled and reset individually. The data are accessible via the debug
filesystem. For details please consult Documentation/trace/histograms.txt.
Signed-off-by: Carsten Emde <C.Emde@osadl.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'kernel/hrtimer.c')
| -rw-r--r-- | kernel/hrtimer.c | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index 383319b..7c4ee68 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -52,6 +52,7 @@ #include <asm/uaccess.h> #include <trace/events/timer.h> +#include <trace/events/hist.h> /* * The timer bases: @@ -997,6 +998,17 @@ int __hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim, #endif } +#ifdef CONFIG_MISSED_TIMER_OFFSETS_HIST + { + ktime_t now = new_base->get_time(); + + if (ktime_to_ns(tim) < ktime_to_ns(now)) + timer->praecox = now; + else + timer->praecox = ktime_set(0, 0); + } +#endif + hrtimer_set_expires_range_ns(timer, tim, delta_ns); timer_stats_hrtimer_set_start_info(timer); @@ -1275,6 +1287,8 @@ static void __run_hrtimer(struct hrtimer *timer, ktime_t *now) #ifdef CONFIG_HIGH_RES_TIMERS +static enum hrtimer_restart hrtimer_wakeup(struct hrtimer *timer); + /* * High resolution timer interrupt * Called with interrupts disabled @@ -1318,6 +1332,15 @@ retry: timer = container_of(node, struct hrtimer, node); + trace_hrtimer_interrupt(raw_smp_processor_id(), + ktime_to_ns(ktime_sub(ktime_to_ns(timer->praecox) ? + timer->praecox : hrtimer_get_expires(timer), + basenow)), + current, + timer->function == hrtimer_wakeup ? + container_of(timer, struct hrtimer_sleeper, + timer)->task : NULL); + /* * The immediate goal for using the softexpires is * minimizing wakeups, not running timers at the |