hrtimer: Fix incorrect tai offset calculation for non high-res timer systems

I noticed some CLOCK_TAI timer test failures on one of my
less-frequently used configurations. And after digging in I
found in 76f4108892 (Cleanup hrtimer accessors to the
timekepeing state), the hrtimer_get_softirq_time tai offset
calucation was incorrectly rewritten, as the tai offset we
return shold be from CLOCK_MONOTONIC, and not CLOCK_REALTIME.

This results in CLOCK_TAI timers expiring early on non-highres
capable machines.

This patch fixes the issue, calculating the tai time properly
from the monotonic base.

Signed-off-by: John Stultz <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: stable <[email protected]> # 3.17+
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
This commit is contained in:
John Stultz 2015-02-04 16:45:26 -08:00 • committed by Ingo Molnar
commit 2d926c15d6

View file

@ -122,7 +122,7 @@ static void hrtimer_get_softirq_time(struct hrtimer_cpu_base *base)
mono = ktime_get_update_offsets_tick(&off_real, &off_boot, &off_tai);
boot = ktime_add(mono, off_boot);
xtim = ktime_add(mono, off_real);
tai = ktime_add(xtim, off_tai);
tai = ktime_add(mono, off_tai);
base->clock_base[HRTIMER_BASE_REALTIME].softirq_time = xtim;
base->clock_base[HRTIMER_BASE_MONOTONIC].softirq_time = mono;