nohz: Fix another inconsistency between CONFIG_NO_HZ=n and nohz=off

If CONFIG_NO_HZ=n tick_nohz_get_sleep_length() returns NSEC_PER_SEC/HZ.

If CONFIG_NO_HZ=y and the nohz functionality is disabled via the
command line option "nohz=off" or not enabled due to missing hardware
support, then tick_nohz_get_sleep_length() returns 0. That happens
because ts->sleep_length is never set in that case.

Set it to NSEC_PER_SEC/HZ when the NOHZ mode is inactive.

Reported-by: Michal Hocko <mhocko@suse.cz>
Reported-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Thomas Gleixner 2013-11-29 12:18:13 +01:00
parent 70fe8217e1
commit 0e576acbc1

View File

@ -711,8 +711,10 @@ static bool can_stop_idle_tick(int cpu, struct tick_sched *ts)
return false;
}
if (unlikely(ts->nohz_mode == NOHZ_MODE_INACTIVE))
if (unlikely(ts->nohz_mode == NOHZ_MODE_INACTIVE)) {
ts->sleep_length = (ktime_t) { .tv64 = NSEC_PER_SEC/HZ };
return false;
}
if (need_resched())
return false;