linux/kernel/sched
Corey Minyard a803f0261b sched: Initialize rq->age_stamp on processor start
If the sched_clock time starts at a large value, the kernel will spin
in sched_avg_update for a long time while rq->age_stamp catches up
with rq->clock.

The comment in kernel/sched/clock.c says that there is no strict promise
that it starts at zero.  So initialize rq->age_stamp when a cpu starts up
to avoid this.

I was seeing long delays on a simulator that didn't start the clock at
zero.  This might also be an issue on reboots on processors that don't
re-initialize the timer to zero on reset, and when using kexec.

Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1399574859-11714-1-git-send-email-minyard@acm.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-05-22 11:16:35 +02:00
..
auto_group.c
auto_group.h
clock.c kernel: use macros from compiler.h instead of __attribute__((...)) 2014-04-07 16:36:11 -07:00
completion.c
core.c sched: Initialize rq->age_stamp on processor start 2014-05-22 11:16:35 +02:00
cpuacct.c
cpuacct.h
cpudeadline.c sched/deadline: Replace NR_CPUS arrays 2014-05-22 10:21:28 +02:00
cpudeadline.h sched/deadline: Replace NR_CPUS arrays 2014-05-22 10:21:28 +02:00
cpupri.c sched/cpupri: Replace NR_CPUS arrays 2014-05-22 10:21:29 +02:00
cpupri.h sched/cpupri: Replace NR_CPUS arrays 2014-05-22 10:21:29 +02:00
cputime.c sched: Sanitize irq accounting madness 2014-05-07 11:51:30 +02:00
deadline.c sched, nohz: Change rq->nr_running to always use wrappers 2014-05-22 11:16:33 +02:00
debug.c Merge branch 'for-3.15' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 2014-04-03 13:05:42 -07:00
fair.c sched, nohz: Change rq->nr_running to always use wrappers 2014-05-22 11:16:33 +02:00
features.h
idle.c Merge branch 'pm-cpuidle' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm into sched/core 2014-05-22 10:37:06 +02:00
idle_task.c
Makefile
proc.c
rt.c sched, nohz: Change rq->nr_running to always use wrappers 2014-05-22 11:16:33 +02:00
sched.h sched, nohz: Change rq->nr_running to always use wrappers 2014-05-22 11:16:33 +02:00
stats.c kernel: audit/fix non-modular users of module_init in core code 2014-04-03 16:21:07 -07:00
stats.h
stop_task.c sched, nohz: Change rq->nr_running to always use wrappers 2014-05-22 11:16:33 +02:00
wait.c