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authorDavid Engraf <david.engraf@sysgo.com>2017-02-17 08:51:03 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-03-22 09:23:21 +0100
commit6c07f47bbadcd54e5b54e539719528bfb146b4c6 (patch)
tree4d5274ddd11a71e8c18af08449b2af4f0f494a23 /kernel
parentfb796cd622706be3b0481f7e0e5f8ed0e2b06d91 (diff)
timers, sched_clock: Update timeout for clock wrap
[ Upstream commit 1b8955bc5ac575009835e371ae55e7f3af2197a9 ] 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> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/time/sched_clock.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/kernel/time/sched_clock.c b/kernel/time/sched_clock.c
index a26036d37a38..382b159d8592 100644
--- a/kernel/time/sched_clock.c
+++ b/kernel/time/sched_clock.c
@@ -205,6 +205,11 @@ 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;