From: Stanislav Meduna <stano@meduna.org>
To: "linux-rt-users@vger.kernel.org" <linux-rt-users@vger.kernel.org>
Subject: Re: hrtimer: interrupt took 6742 ns, then RT throttling and hung machine for nearly 2 seconds
Date: Mon, 15 Apr 2013 13:54:01 +0200 [thread overview]
Message-ID: <516BEA59.4050303@meduna.org> (raw)
In-Reply-To: <516BDE52.90200@meduna.org>
On 15.04.2013 13:02, Stanislav Meduna wrote:
> Apr 15 10:14:57 lnx kernel: [56281.700293] hrtimer: interrupt took 6742 ns
The /proc/timer_list follows. What worries me a bit are the retries -
they are slowly rising (~1 / sec for nr_retries) even if the machine
is basically idle. Is it normal?
The rise only happens if our application is running, but it is
basically the only thing in system that is actively using
the hrtimers, so this does not really say much. Tweaking
the priority of ksoftirqd has no effect.
Timer List Version: v0.6
HRTIMER_MAX_CLOCK_BASES: 3
now at 342575389945882 nsecs
cpu: 0
clock 0:
.base: c04d7f68
.index: 0
.resolution: 1 nsecs
.get_time: ktime_get
.offset: 0 nsecs
active timers:
#0: tick_cpu_sched, tick_sched_timer, S:01
# expires at 342575390000000-342575390000000 nsecs [in 54118 to 54118
nsecs]
#1: <cd9bb680>, timerfd_tmrproc, S:01
# expires at 342575390284003-342575390284003 nsecs [in 338121 to 338121
nsecs]
#2: <cc6cff48>, hrtimer_wakeup, S:01
# expires at 342575390421978-342575390421978 nsecs [in 476096 to 476096
nsecs]
... 16 more hrtimer_wakeup follow ...
clock 1:
.base: c04d7fa0
.index: 1
.resolution: 1 nsecs
.get_time: ktime_get_real
.offset: 1365682957275692841 nsecs
active timers:
clock 2:
.base: c04d7fd8
.index: 2
.resolution: 1 nsecs
.get_time: ktime_get_boottime
.offset: 0 nsecs
active timers:
.expires_next : 342575390284003 nsecs
.hres_active : 1
.nr_events : 556415337
.nr_retries : 1124752
.nr_hangs : 1
.max_hang_time : 6742 nsecs
.nohz_mode : 2
.idle_tick : 342575389000000 nsecs
.tick_stopped : 0
.idle_jiffies : 342275388
.idle_calls : 514502119
.idle_sleeps : 510841382
.idle_entrytime : 342575388177611 nsecs
.idle_waketime : 342575388177611 nsecs
.idle_exittime : 342575388184375 nsecs
.idle_sleeptime : 301580528758450 nsecs
.iowait_sleeptime: 21756268924 nsecs
.last_jiffies : 342275388
.next_jiffies : 342275421
.idle_expires : 342575421000000 nsecs
jiffies: 342275390
Tick Device: mode: 1
Per CPU device: 0
Clock Event Device: hpet
max_delta_ns: 149983013276
min_delta_ns: 13409
mult: 61496111
shift: 32
mode: 3
next_event: 342575390284003 nsecs
set_next_event: hpet_legacy_next_event
set_mode: hpet_legacy_set_mode
event_handler: hrtimer_interrupt
retries: 9359
Regards
--
Stano
next prev parent reply other threads:[~2013-04-15 11:54 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-04-15 11:02 hrtimer: interrupt took 6742 ns, then RT throttling and hung machine for nearly 2 seconds Stanislav Meduna
2013-04-15 11:54 ` Stanislav Meduna [this message]
2013-04-15 12:22 ` Thomas Gleixner
2013-04-15 12:56 ` Stanislav Meduna
2013-04-17 15:46 ` timerfd and softirqd [Was: Re: hrtimer: interrupt took 6742 ns, then RT throttling and hung machine for nearly 2 seconds] Stanislav Meduna
2013-04-18 9:11 ` timerfd read does not return [Was: Re: timerfd and softirqd] Stanislav Meduna
2013-04-19 19:53 ` Stanislav Meduna
2013-04-22 7:35 ` [PATCH] Re: timerfd read does not return Stanislav Meduna
2013-04-22 8:55 ` Stanislav Meduna
2013-04-27 8:34 ` timerfd read does not return - was probably fixed in 3.4.38 Stanislav Meduna
2013-04-28 11:53 ` Carsten Emde
2013-04-29 8:43 ` Stanislav Meduna
2013-05-02 20:02 ` Steven Rostedt
2013-05-10 12:42 ` timerfd read does not return - some traces Stanislav Meduna
2013-05-12 17:31 ` Stanislav Meduna
2013-05-12 23:20 ` timerfd read does not return - hangs inside put_user Stanislav Meduna
2013-05-13 8:05 ` timerfd read does not return - caused by MM fault Stanislav Meduna
2013-05-14 8:31 ` Livelock in handle_pte_fault [Was: Re: timerfd read does not return] Stanislav Meduna
2013-11-25 10:36 ` Vijay Katoch
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