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| author | Ingo Molnar <mingo@kernel.org> | 2020-02-24 11:36:09 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2020-02-24 11:36:09 +0100 |
| commit | 546121b65f47384e11ec1fa2e55449fc9f4846b2 (patch) | |
| tree | 8f18470ec7c0c77b0f48eb1b2338e591b0b0aaff /kernel/time/tick-sched.c | |
| parent | 000619680c3714020ce9db17eef6a4a7ce2dc28b (diff) | |
| parent | f8788d86ab28f61f7b46eb6be375f8a726783636 (diff) | |
Merge tag 'v5.6-rc3' into sched/core, to pick up fixes and dependent patches
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/time/tick-sched.c')
| -rw-r--r-- | kernel/time/tick-sched.c | 14 |
1 files changed, 9 insertions, 5 deletions
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 8b192e67aabc..a792d21cac64 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -58,8 +58,9 @@ static void tick_do_update_jiffies64(ktime_t now) /* * Do a quick check without holding jiffies_lock: + * The READ_ONCE() pairs with two updates done later in this function. */ - delta = ktime_sub(now, last_jiffies_update); + delta = ktime_sub(now, READ_ONCE(last_jiffies_update)); if (delta < tick_period) return; @@ -70,8 +71,9 @@ static void tick_do_update_jiffies64(ktime_t now) if (delta >= tick_period) { delta = ktime_sub(delta, tick_period); - last_jiffies_update = ktime_add(last_jiffies_update, - tick_period); + /* Pairs with the lockless read in this function. */ + WRITE_ONCE(last_jiffies_update, + ktime_add(last_jiffies_update, tick_period)); /* Slow path for long timeouts */ if (unlikely(delta >= tick_period)) { @@ -79,8 +81,10 @@ static void tick_do_update_jiffies64(ktime_t now) ticks = ktime_divns(delta, incr); - last_jiffies_update = ktime_add_ns(last_jiffies_update, - incr * ticks); + /* Pairs with the lockless read in this function. */ + WRITE_ONCE(last_jiffies_update, + ktime_add_ns(last_jiffies_update, + incr * ticks)); } do_timer(++ticks); |