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author | Thomas Gleixner <tglx@linutronix.de> | 2013-11-29 11:18:13 (GMT) |
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committer | Thomas Gleixner <tglx@linutronix.de> | 2013-11-29 11:23:03 (GMT) |
commit | 0e576acbc1d9600cf2d9b4a141a2554639959d50 (patch) | |
tree | 1d1322330afaa7cffdc39d2f898a7a0f02fa65c3 | |
parent | 70fe8217e17ddd058f9f043ae1cc0d86b1658a5c (diff) | |
download | linux-0e576acbc1d9600cf2d9b4a141a2554639959d50.tar.xz |
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>
-rw-r--r-- | kernel/time/tick-sched.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index a12df5a..ea20f7d 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -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; |