From: David Engraf Date: Fri, 17 Feb 2017 07:51:03 +0000 (+0100) Subject: timers, sched_clock: Update timeout for clock wrap X-Git-Tag: v4.12-rc1~157^2~16^2~1 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=1b8955bc5ac575009835e371ae55e7f3af2197a9;p=karo-tx-linux.git 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 Signed-off-by: John Stultz --- diff --git a/kernel/time/sched_clock.c b/kernel/time/sched_clock.c index ea6b610c4c57..2d8f05aad442 100644 --- a/kernel/time/sched_clock.c +++ b/kernel/time/sched_clock.c @@ -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;