diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2018-01-15 01:30:51 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2018-01-16 04:35:44 +0300 |
| commit | ae67badaa1643253998cb21d5782e4ea7c231a29 (patch) | |
| tree | 9d12382a6e79d9d6420796d2cca2c6853b9aeed2 /include/linux/hrtimer.h | |
| parent | 57957fb519449803df30d10da433c27aaad17fa5 (diff) | |
| download | linux-ae67badaa1643253998cb21d5782e4ea7c231a29.tar.xz | |
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 'include/linux/hrtimer.h')
| -rw-r--r-- | include/linux/hrtimer.h | 4 |
1 files changed, 0 insertions, 4 deletions
diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h index 012c37fdb688..79b2a8d29d8c 100644 --- a/include/linux/hrtimer.h +++ b/include/linux/hrtimer.h @@ -153,8 +153,6 @@ enum hrtimer_base_type { * @cpu: cpu number * @active_bases: Bitfield to mark bases with active timers * @clock_was_set_seq: Sequence counter of clock was set events - * @migration_enabled: The migration of hrtimers to other cpus is enabled - * @nohz_active: The nohz functionality is enabled * @expires_next: absolute time of the next event which was scheduled * via clock_set_next_event() * @next_timer: Pointer to the first expiring timer @@ -178,8 +176,6 @@ struct hrtimer_cpu_base { unsigned int cpu; unsigned int active_bases; unsigned int clock_was_set_seq; - bool migration_enabled; - bool nohz_active; #ifdef CONFIG_HIGH_RES_TIMERS unsigned int in_hrtirq : 1, hres_active : 1, |