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| author | Thomas Gleixner <tglx@linutronix.de> | 2013-11-29 12:18:13 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-06-26 15:12:41 -0400 |
| commit | ec804bd9e1ecad7a6d9f9428eaf388e3dac9cb63 (patch) | |
| tree | 5c847b8f464893a1016aa34d3536f538d7b177ca | |
| parent | feaad01723471c67e10f5c5bc537299e686f78b8 (diff) | |
| download | linux-stable-ec804bd9e1ecad7a6d9f9428eaf388e3dac9cb63.tar.gz linux-stable-ec804bd9e1ecad7a6d9f9428eaf388e3dac9cb63.tar.bz2 linux-stable-ec804bd9e1ecad7a6d9f9428eaf388e3dac9cb63.zip | |
nohz: Fix another inconsistency between CONFIG_NO_HZ=n and nohz=off
commit 0e576acbc1d9600cf2d9b4a141a2554639959d50 upstream.
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>
Cc: Rui Xiang <rui.xiang@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -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 4251374578bc..67f7a2d2efbc 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -720,8 +720,10 @@ 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; |