Commit-ID: 1b8955bc5ac575009835e371ae55e7f3af2197a9
Gitweb: http://git.kernel.org/tip/1b8955bc5ac575009835e371ae55e7f3af2197a9
Author: David Engraf <david.engraf@xxxxxxxxx>
AuthorDate: Fri, 17 Feb 2017 08:51:03 +0100
Committer: John Stultz <john.stultz@xxxxxxxxxx>
CommitDate: Thu, 23 Mar 2017 12:30:27 -0700
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@xxxxxxxxx>
Signed-off-by: John Stultz <john.stultz@xxxxxxxxxx>
---
kernel/time/sched_clock.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/kernel/time/sched_clock.c b/kernel/time/sched_clock.c
index ea6b610..2d8f05a 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;
--
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