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| author | Yunfeng Ye <yeyunfeng@huawei.com> | 2020-11-17 14:19:48 +0100 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2020-11-19 10:48:29 +0100 |
| commit | 896b969e6732b68ee3c12ae4e1aeddf5db99bc46 (patch) | |
| tree | e30a383f2649a1e6f5d32ad6031c845d2571b182 /kernel/time | |
| parent | tick/sched: Optimize tick_do_update_jiffies64() further (diff) | |
| download | linux-896b969e6732b68ee3c12ae4e1aeddf5db99bc46.tar.xz linux-896b969e6732b68ee3c12ae4e1aeddf5db99bc46.zip | |
tick/sched: Release seqcount before invoking calc_load_global()
calc_load_global() does not need the sequence count protection.
[ tglx: Split it up properly and added comments ]
Signed-off-by: Yunfeng Ye <yeyunfeng@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201117132006.660902274@linutronix.de
Diffstat (limited to 'kernel/time')
| -rw-r--r-- | kernel/time/tick-sched.c | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 306adeb6ce4c..33c897bb88c6 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -20,6 +20,7 @@ #include <linux/sched/clock.h> #include <linux/sched/stat.h> #include <linux/sched/nohz.h> +#include <linux/sched/loadavg.h> #include <linux/module.h> #include <linux/irq_work.h> #include <linux/posix-timers.h> @@ -107,7 +108,8 @@ static void tick_do_update_jiffies64(ktime_t now) tick_period); } - do_timer(ticks); + /* Advance jiffies to complete the jiffies_seq protected job */ + jiffies_64 += ticks; /* * Keep the tick_next_period variable up to date. WRITE_ONCE() @@ -116,7 +118,15 @@ static void tick_do_update_jiffies64(ktime_t now) WRITE_ONCE(tick_next_period, ktime_add(last_jiffies_update, tick_period)); + /* + * Release the sequence count. calc_global_load() below is not + * protected by it, but jiffies_lock needs to be held to prevent + * concurrent invocations. + */ write_seqcount_end(&jiffies_seq); + + calc_global_load(); + raw_spin_unlock(&jiffies_lock); update_wall_time(); } |