diff options
author | Viresh Kumar <viresh.kumar@linaro.org> | 2015-03-25 12:07:31 +0530 |
---|---|---|
committer | Olav Haugan <ohaugan@codeaurora.org> | 2016-09-20 17:47:12 -0700 |
commit | f461d408acb522ec6db8ae34a49c2dbbd6092ab1 (patch) | |
tree | 750b410227fd532cbd693b42a079c9ccee5c8fd6 /kernel/time/hrtimer.c | |
parent | d0cea65e27b7541234d61b70017ec6cc3cfe3eec (diff) |
hrtimer: create hrtimer_quiesce_cpu() to isolate CPU from hrtimers
To isolate CPUs (isolate from hrtimers) from sysfs using cpusets, we need some
support from the hrtimer core. i.e. A routine hrtimer_quiesce_cpu() which would
migrate away all the unpinned hrtimers, but shouldn't touch the pinned ones.
This patch creates this routine.
Change-Id: I51259ea41e3bd5cdba50b718201a6840174a7224
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
[forward port to 3.18]
Signed-off-by: Santosh Shukla <santosh.shukla@linaro.org>
[ohaugan@codeaurora.org: Port to 4.4]
Git-commit: d4d50a0ddc35e58ee95137ba4d14e74fea8b682f
Git-repo: git://git.linaro.org/people/mike.holmes/santosh.shukla/lng-isol.git
Signed-off-by: Olav Haugan <ohaugan@codeaurora.org>
Diffstat (limited to 'kernel/time/hrtimer.c')
-rw-r--r-- | kernel/time/hrtimer.c | 54 |
1 files changed, 44 insertions, 10 deletions
diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c index 83c298cc0533..44ddf403fb01 100644 --- a/kernel/time/hrtimer.c +++ b/kernel/time/hrtimer.c @@ -1623,13 +1623,17 @@ static void init_hrtimers_cpu(int cpu) hrtimer_init_hres(cpu_base); } -#ifdef CONFIG_HOTPLUG_CPU - +#if defined(CONFIG_HOTPLUG_CPU) || defined(CONFIG_CPUSETS) static void migrate_hrtimer_list(struct hrtimer_clock_base *old_base, - struct hrtimer_clock_base *new_base) + struct hrtimer_clock_base *new_base, + bool remove_pinned) { struct hrtimer *timer; struct timerqueue_node *node; + struct timerqueue_head pinned; + int is_pinned; + + timerqueue_init_head(&pinned); while ((node = timerqueue_getnext(&old_base->active))) { timer = container_of(node, struct hrtimer, node); @@ -1642,6 +1646,13 @@ static void migrate_hrtimer_list(struct hrtimer_clock_base *old_base, * under us on another CPU */ __remove_hrtimer(timer, old_base, HRTIMER_STATE_ENQUEUED, 0); + + is_pinned = timer->state & HRTIMER_STATE_PINNED; + if (!remove_pinned && is_pinned) { + timerqueue_add(&pinned, &timer->node); + continue; + } + timer->base = new_base; /* * Enqueue the timers on the new cpu. This does not @@ -1653,17 +1664,23 @@ static void migrate_hrtimer_list(struct hrtimer_clock_base *old_base, */ enqueue_hrtimer(timer, new_base); } + + /* Re-queue pinned timers for non-hotplug usecase */ + while ((node = timerqueue_getnext(&pinned))) { + timer = container_of(node, struct hrtimer, node); + + timerqueue_del(&pinned, &timer->node); + enqueue_hrtimer(timer, old_base); + } } -static void migrate_hrtimers(int scpu) +static void __migrate_hrtimers(int scpu, bool remove_pinned) { struct hrtimer_cpu_base *old_base, *new_base; + unsigned long flags; int i; - BUG_ON(cpu_online(scpu)); - tick_cancel_sched_timer(scpu); - - local_irq_disable(); + local_irq_save(flags); old_base = &per_cpu(hrtimer_bases, scpu); new_base = this_cpu_ptr(&hrtimer_bases); /* @@ -1675,7 +1692,7 @@ static void migrate_hrtimers(int scpu) for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) { migrate_hrtimer_list(&old_base->clock_base[i], - &new_base->clock_base[i]); + &new_base->clock_base[i], remove_pinned); } raw_spin_unlock(&old_base->lock); @@ -1683,11 +1700,28 @@ static void migrate_hrtimers(int scpu) /* Check, if we got expired work to do */ __hrtimer_peek_ahead_timers(); - local_irq_enable(); + local_irq_restore(flags); +} +#endif /* CONFIG_HOTPLUG_CPU || CONFIG_CPUSETS */ + +#ifdef CONFIG_HOTPLUG_CPU +static void migrate_hrtimers(int scpu) +{ + BUG_ON(cpu_online(scpu)); + tick_cancel_sched_timer(scpu); + + __migrate_hrtimers(scpu, true); } #endif /* CONFIG_HOTPLUG_CPU */ +#ifdef CONFIG_CPUSETS +void hrtimer_quiesce_cpu(void *cpup) +{ + __migrate_hrtimers(*(int *)cpup, false); +} +#endif /* CONFIG_CPUSETS */ + static int hrtimer_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu) { |