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| author | Thomas Gleixner <tglx@linutronix.de> | 2018-01-14 23:30:51 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2018-01-16 02:35:44 +0100 |
| commit | ae67badaa1643253998cb21d5782e4ea7c231a29 (patch) | |
| tree | 9d12382a6e79d9d6420796d2cca2c6853b9aeed2 /kernel/time/tick-sched.c | |
| parent | Merge branch 'timers/urgent' into timers/core, to pick up dependent fix (diff) | |
| download | linux-ae67badaa1643253998cb21d5782e4ea7c231a29.tar.xz linux-ae67badaa1643253998cb21d5782e4ea7c231a29.zip | |
hrtimer: Optimize the hrtimer code by using static keys for migration_enable/nohz_active
The hrtimer_cpu_base::migration_enable and ::nohz_active fields
were originally introduced to avoid accessing global variables
for these decisions.
Still that results in a (cache hot) load and conditional branch,
which can be avoided by using static keys.
Implement it with static keys and optimize for the most critical
case of high performance networking which tends to disable the
timer migration functionality.
No change in functionality.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Anna-Maria Gleixner <anna-maria@linutronix.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: keescook@chromium.org
Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1801142327490.2371@nanos
Link: https://lkml.kernel.org/r/20171221104205.7269-2-anna-maria@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/time/tick-sched.c')
| -rw-r--r-- | kernel/time/tick-sched.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index f7cc7abfcf25..29a5733eff83 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -1107,7 +1107,7 @@ static inline void tick_nohz_activate(struct tick_sched *ts, int mode) ts->nohz_mode = mode; /* One update is enough */ if (!test_and_set_bit(0, &tick_nohz_active)) - timers_update_migration(true); + timers_update_nohz(); } /** |