From: "Rafael J. Wysocki" <rjw@rjwysocki.net>
To: Linux PM <linux-pm@vger.kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>,
Frederic Weisbecker <fweisbec@gmail.com>,
Thomas Gleixner <tglx@linutronix.de>,
Paul McKenney <paulmck@linux.vnet.ibm.com>,
Thomas Ilsche <thomas.ilsche@tu-dresden.de>,
Doug Smythies <dsmythies@telus.net>,
Rik van Riel <riel@surriel.com>,
Aubrey Li <aubrey.li@linux.intel.com>,
Mike Galbraith <mgalbraith@suse.de>,
LKML <linux-kernel@vger.kernel.org>,
Len Brown <len.brown@intel.com>
Subject: [PATCH v9 07/10] time: hrtimer: Introduce hrtimer_next_event_without()
Date: Wed, 04 Apr 2018 10:45:39 +0200 [thread overview]
Message-ID: <101528364.6nGUqP0EsC@aspire.rjw.lan> (raw)
In-Reply-To: <1736751.LdhZHb50jq@aspire.rjw.lan>
From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The next set of changes will need to compute the time to the next
hrtimer event over all hrtimers except for the scheduler tick one.
To that end introduce a new helper function,
hrtimer_next_event_without(), for computing the time until the next
hrtimer event over all timers except for one and modify the underlying
code in __hrtimer_next_event_base() to prepare it for being called by
that new function.
No intentional changes in functionality.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
v8 -> v9:
* Make fewer changes to the existing code.
* Add a new helper function for the handling of the use case at hand.
---
include/linux/hrtimer.h | 1
kernel/time/hrtimer.c | 55 ++++++++++++++++++++++++++++++++++++++++++++++--
2 files changed, 54 insertions(+), 2 deletions(-)
Index: linux-pm/include/linux/hrtimer.h
===================================================================
--- linux-pm.orig/include/linux/hrtimer.h
+++ linux-pm/include/linux/hrtimer.h
@@ -426,6 +426,7 @@ static inline ktime_t hrtimer_get_remain
}
extern u64 hrtimer_get_next_event(void);
+extern u64 hrtimer_next_event_without(const struct hrtimer *exclude);
extern bool hrtimer_active(const struct hrtimer *timer);
Index: linux-pm/kernel/time/hrtimer.c
===================================================================
--- linux-pm.orig/kernel/time/hrtimer.c
+++ linux-pm/kernel/time/hrtimer.c
@@ -490,6 +490,7 @@ __next_base(struct hrtimer_cpu_base *cpu
while ((base = __next_base((cpu_base), &(active))))
static ktime_t __hrtimer_next_event_base(struct hrtimer_cpu_base *cpu_base,
+ const struct hrtimer *exclude,
unsigned int active,
ktime_t expires_next)
{
@@ -502,9 +503,24 @@ static ktime_t __hrtimer_next_event_base
next = timerqueue_getnext(&base->active);
timer = container_of(next, struct hrtimer, node);
+ if (timer == exclude) {
+ /* Get to the next timer in the queue. */
+ struct rb_node *rbn = rb_next(&next->node);
+
+ next = rb_entry_safe(rbn, struct timerqueue_node, node);
+ if (!next)
+ continue;
+
+ timer = container_of(next, struct hrtimer, node);
+ }
expires = ktime_sub(hrtimer_get_expires(timer), base->offset);
if (expires < expires_next) {
expires_next = expires;
+
+ /* Skip cpu_base update if a timer is being excluded. */
+ if (exclude)
+ continue;
+
if (timer->is_soft)
cpu_base->softirq_next_timer = timer;
else
@@ -548,7 +564,8 @@ __hrtimer_get_next_event(struct hrtimer_
if (!cpu_base->softirq_activated && (active_mask & HRTIMER_ACTIVE_SOFT)) {
active = cpu_base->active_bases & HRTIMER_ACTIVE_SOFT;
cpu_base->softirq_next_timer = NULL;
- expires_next = __hrtimer_next_event_base(cpu_base, active, KTIME_MAX);
+ expires_next = __hrtimer_next_event_base(cpu_base, NULL,
+ active, KTIME_MAX);
next_timer = cpu_base->softirq_next_timer;
}
@@ -556,7 +573,8 @@ __hrtimer_get_next_event(struct hrtimer_
if (active_mask & HRTIMER_ACTIVE_HARD) {
active = cpu_base->active_bases & HRTIMER_ACTIVE_HARD;
cpu_base->next_timer = next_timer;
- expires_next = __hrtimer_next_event_base(cpu_base, active, expires_next);
+ expires_next = __hrtimer_next_event_base(cpu_base, NULL, active,
+ expires_next);
}
return expires_next;
@@ -1200,6 +1218,39 @@ u64 hrtimer_get_next_event(void)
raw_spin_unlock_irqrestore(&cpu_base->lock, flags);
+ return expires;
+}
+
+/**
+ * hrtimer_next_event_without - time until next expiry event w/o one timer
+ * @exclude: timer to exclude
+ *
+ * Returns the next expiry time over all timers except for the @exclude one or
+ * KTIME_MAX if none of them is pending.
+ */
+u64 hrtimer_next_event_without(const struct hrtimer *exclude)
+{
+ struct hrtimer_cpu_base *cpu_base = this_cpu_ptr(&hrtimer_bases);
+ u64 expires = KTIME_MAX;
+ unsigned long flags;
+
+ raw_spin_lock_irqsave(&cpu_base->lock, flags);
+
+ if (__hrtimer_hres_active(cpu_base)) {
+ unsigned int active;
+
+ if (!cpu_base->softirq_activated) {
+ active = cpu_base->active_bases & HRTIMER_ACTIVE_SOFT;
+ expires = __hrtimer_next_event_base(cpu_base, exclude,
+ active, KTIME_MAX);
+ }
+ active = cpu_base->active_bases & HRTIMER_ACTIVE_HARD;
+ expires = __hrtimer_next_event_base(cpu_base, exclude, active,
+ expires);
+ }
+
+ raw_spin_unlock_irqrestore(&cpu_base->lock, flags);
+
return expires;
}
#endif
next prev parent reply other threads:[~2018-04-04 8:45 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-04-04 8:32 [PATCH v9 00/10] sched/cpuidle: Idle loop rework Rafael J. Wysocki
2018-04-04 8:33 ` [PATCH v9 01/10] time: tick-sched: Reorganize idle tick management code Rafael J. Wysocki
2018-04-04 8:34 ` [PATCH v9 02/10] sched: idle: Do not stop the tick upfront in the idle loop Rafael J. Wysocki
2018-04-04 8:36 ` [PATCH v9 03/10] sched: idle: Do not stop the tick before cpuidle_idle_call() Rafael J. Wysocki
2018-04-04 8:38 ` [PATCH v9 04/10] jiffies: Introduce USER_TICK_USEC and redefine TICK_USEC Rafael J. Wysocki
2018-04-06 1:09 ` Frederic Weisbecker
2018-04-06 7:20 ` Rafael J. Wysocki
2018-04-04 8:39 ` [PATCH v9 05/10] cpuidle: Return nohz hint from cpuidle_select() Rafael J. Wysocki
2018-04-06 2:44 ` Frederic Weisbecker
2018-04-06 7:24 ` Rafael J. Wysocki
2018-04-06 14:19 ` Frederic Weisbecker
2018-04-06 7:58 ` Peter Zijlstra
2018-04-06 14:23 ` Frederic Weisbecker
2018-04-06 8:11 ` Rafael J. Wysocki
2018-04-06 12:56 ` Rafael J. Wysocki
2018-04-06 15:28 ` Frederic Weisbecker
2018-04-06 14:28 ` Frederic Weisbecker
2018-04-04 8:41 ` [PATCH v9 06/10] time: tick-sched: Split tick_nohz_stop_sched_tick() Rafael J. Wysocki
2018-04-07 2:36 ` Frederic Weisbecker
2018-04-07 16:36 ` Rafael J. Wysocki
2018-04-04 8:45 ` Rafael J. Wysocki [this message]
2018-04-07 14:46 ` [PATCH v9 07/10] time: hrtimer: Introduce hrtimer_next_event_without() Frederic Weisbecker
2018-04-08 8:20 ` Rafael J. Wysocki
2018-04-08 17:58 ` Frederic Weisbecker
2018-04-04 8:47 ` [PATCH v9 08/10] sched: idle: Select idle state before stopping the tick Rafael J. Wysocki
2018-04-09 2:41 ` Frederic Weisbecker
2018-04-04 8:49 ` [PATCH v9 09/10] cpuidle: menu: Refine idle state selection for running tick Rafael J. Wysocki
2018-04-05 12:27 ` Peter Zijlstra
2018-04-05 13:51 ` Rafael J. Wysocki
2018-04-05 12:32 ` Peter Zijlstra
2018-04-05 13:52 ` Rafael J. Wysocki
2018-04-04 8:50 ` [PATCH v9 10/10] cpuidle: menu: Avoid selecting shallow states with stopped tick Rafael J. Wysocki
2018-04-05 12:47 ` Peter Zijlstra
2018-04-05 13:49 ` Rafael J. Wysocki
2018-04-05 14:11 ` Peter Zijlstra
2018-04-05 14:13 ` Peter Zijlstra
2018-04-05 14:29 ` Rafael J. Wysocki
2018-04-08 16:32 ` [PATCH v9 00/10] sched/cpuidle: Idle loop rework Rafael J. Wysocki
2018-04-09 15:58 ` Thomas Ilsche
2018-04-10 7:03 ` Rafael J. Wysocki
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