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author | Max Krummenacher <max.krummenacher@toradex.com> | 2018-03-13 11:32:58 +0100 |
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committer | Max Krummenacher <max.krummenacher@toradex.com> | 2018-03-13 11:32:58 +0100 |
commit | 6fb9f3c8a4992f67dcb3ce413df2e22e96b2d400 (patch) | |
tree | 6e3071b2f179a62b027669ac2a238383293bf941 /kernel/time/tick-sched.c | |
parent | a126a5e5dc2fcc5cb36af14c89b440cc8e3bab30 (diff) | |
parent | 8b5ab55d254f36e89b1b53aeac7223d2d102483e (diff) |
Merge tag 'v4.4.121' into toradex_vf_4.4-nextColibri-VF_LXDE-Image_2.8b2.97-20180331
This is the 4.4.121 stable release
Diffstat (limited to 'kernel/time/tick-sched.c')
-rw-r--r-- | kernel/time/tick-sched.c | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 22c57e191a23..e5d228f7224c 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -568,6 +568,11 @@ static void tick_nohz_restart(struct tick_sched *ts, ktime_t now) tick_program_event(hrtimer_get_expires(&ts->sched_timer), 1); } +static inline bool local_timer_softirq_pending(void) +{ + return local_softirq_pending() & TIMER_SOFTIRQ; +} + static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts, ktime_t now, int cpu) { @@ -584,8 +589,18 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts, } while (read_seqretry(&jiffies_lock, seq)); ts->last_jiffies = basejiff; - if (rcu_needs_cpu(basemono, &next_rcu) || - arch_needs_cpu() || irq_work_needs_cpu()) { + /* + * Keep the periodic tick, when RCU, architecture or irq_work + * requests it. + * Aside of that check whether the local timer softirq is + * pending. If so its a bad idea to call get_next_timer_interrupt() + * because there is an already expired timer, so it will request + * immeditate expiry, which rearms the hardware timer with a + * minimal delta which brings us back to this place + * immediately. Lather, rinse and repeat... + */ + if (rcu_needs_cpu(basemono, &next_rcu) || arch_needs_cpu() || + irq_work_needs_cpu() || local_timer_softirq_pending()) { next_tick = basemono + TICK_NSEC; } else { /* |