The following commit has been merged into the timers/core branch of tip: Commit-ID: 896b969e6732b68ee3c12ae4e1aeddf5db99bc46 Gitweb: https://git.kernel.org/tip/896b969e6732b68ee3c12ae4e1aeddf5db99bc46 Author: Yunfeng Ye <yeyunfeng@xxxxxxxxxx> AuthorDate: Tue, 17 Nov 2020 14:19:48 +01:00 Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx> CommitterDate: Thu, 19 Nov 2020 10:48:29 +01:00 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@xxxxxxxxxx> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20201117132006.660902274@xxxxxxxxxxxxx --- kernel/time/tick-sched.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 306adeb..33c897b 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(); }
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