timers, sched_clock: Update timeout for clock wrap

The scheduler clock framework may not use the correct timeout for the clock
wrap. This happens when a new clock driver calls sched_clock_register()
after the kernel called sched_clock_postinit(). In this case the clock wrap
timeout is too long thus sched_clock_poll() is called too late and the clock
already wrapped.

On my ARM system the scheduler was no longer scheduling any other task than
the idle task because the sched_clock() wrapped.

Signed-off-by: David Engraf <david.engraf@sysgo.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
This commit is contained in:
David Engraf 2017-02-17 08:51:03 +01:00 committed by John Stultz
parent e1c09219af
commit 1b8955bc5a
1 changed files with 5 additions and 0 deletions

View File

@ -206,6 +206,11 @@ sched_clock_register(u64 (*read)(void), int bits, unsigned long rate)
update_clock_read_data(&rd);
if (sched_clock_timer.function != NULL) {
/* update timeout for clock wrap */
hrtimer_start(&sched_clock_timer, cd.wrap_kt, HRTIMER_MODE_REL);
}
r = rate;
if (r >= 4000000) {
r /= 1000000;