diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2017-02-16 12:19:18 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-02-16 12:19:18 -0800 |
| commit | 558e8e27e73f53f8a512485be538b07115fe5f3c (patch) | |
| tree | 7a2f37e7a575537db37ee1238471bbb4f3e0a488 /kernel/time/tick-sched.c | |
| parent | 4695daefba8df8a11fa0b0edd595eedae9ea59ae (diff) | |
Revert "nohz: Fix collision between tick and other hrtimers"
This reverts commit 24b91e360ef521a2808771633d76ebc68bd5604b and commit
7bdb59f1ad47 ("tick/nohz: Fix possible missing clock reprog after tick
soft restart") that depends on it,
Pavel reports that it causes occasional boot hangs for him that seem to
depend on just how the machine was booted. In particular, his machine
hangs at around the PCI fixups of the EHCI USB host controller, but only
hangs from cold boot, not from a warm boot.
Thomas Gleixner suspecs it's a CPU hotplug interaction, particularly
since Pavel also saw suspend/resume issues that seem to be related.
We're reverting for now while trying to figure out the root cause.
Reported-bisected-and-tested-by: Pavel Machek <pavel@ucw.cz>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Wanpeng Li <wanpeng.li@hotmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@kernel.org # reverted commits were marked for stable
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/time/tick-sched.c')
| -rw-r--r-- | kernel/time/tick-sched.c | 14 |
1 files changed, 2 insertions, 12 deletions
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index fc6f740d0277..2c115fdab397 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -725,11 +725,6 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts, */ if (delta == 0) { tick_nohz_restart(ts, now); - /* - * Make sure next tick stop doesn't get fooled by past - * clock deadline - */ - ts->next_tick = 0; goto out; } } @@ -772,7 +767,7 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts, tick = expires; /* Skip reprogram of event if its not changed */ - if (ts->tick_stopped && (expires == ts->next_tick)) + if (ts->tick_stopped && (expires == dev->next_event)) goto out; /* @@ -792,8 +787,6 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts, trace_tick_stop(1, TICK_DEP_MASK_NONE); } - ts->next_tick = tick; - /* * If the expiration time == KTIME_MAX, then we simply stop * the tick timer. @@ -809,10 +802,7 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts, else tick_program_event(tick, 1); out: - /* - * Update the estimated sleep length until the next timer - * (not only the tick). - */ + /* Update the estimated sleep length */ ts->sleep_length = ktime_sub(dev->next_event, now); return tick; } |