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| author | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-01-21 19:36:59 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-01-21 19:36:59 +0100 |
| commit | dd7d99dc688d0fc448976f52f8517fbdeccdccda (patch) | |
| tree | 4ad59de5d584cf03e772ee153260c24ba0d717bd /kernel/time/tick-sched.c | |
| parent | 42bbdd99221bac206dde2b5e87098177fcd2a48e (diff) | |
| parent | def9d2780727cec3313ed3522d0123158d87224d (diff) | |
Merge 5.5-rc7 into usb-next
We need the USB fixes in here as well.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.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); |