From: Preeti U Murthy <preeti@linux.vnet.ibm.com>
To: Thomas Gleixner <tglx@linutronix.de>,
LKML <linux-kernel@vger.kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@kernel.org>,
Viresh Kumar <viresh.kumar@linaro.org>,
Marcelo Tosatti <mtosatt@redhat.com>,
Frederic Weisbecker <fweisbec@gmail.com>
Subject: Re: [patch 10/39] hrtimer: Use cpu_base->active_base for hotpath iterators
Date: Mon, 20 Apr 2015 16:46:31 +0530 [thread overview]
Message-ID: <5534E00F.2040606@linux.vnet.ibm.com> (raw)
In-Reply-To: <20150414203501.322887675@linutronix.de>
On 04/15/2015 02:38 AM, Thomas Gleixner wrote:
>>Now that we have the active_bases field in sync we can use it for
This sentence appears a bit ambiguous. I am guessing you are referring
to what the first patch in this series did, in which case wouldn't it be
better if it is stated a bit more elaborately like 'Now that it is
guaranteed that active_bases field will be in sync with the timerqueue
on the corresponding clock base' ? It took me a while to figure out what
the statement was referring to.
>>iterating over the clock bases. This allows to break out early if no
>>more active clock bases are available and avoids touching the cache
>>lines of inactive clock bases.
>>
>>Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
>>---
Regards
Preeti U Murthy
>> kernel/time/hrtimer.c | 17 ++++++++---------
>> 1 file changed, 8 insertions(+), 9 deletions(-)
>>
>>Index: tip/kernel/time/hrtimer.c
>>===================================================================
>>--- tip.orig/kernel/time/hrtimer.c
>>+++ tip/kernel/time/hrtimer.c
>>@@ -419,16 +419,16 @@ static ktime_t __hrtimer_get_next_event(
>> {
>> struct hrtimer_clock_base *base = cpu_base->clock_base;
>> ktime_t expires, expires_next = { .tv64 = KTIME_MAX };
>>- int i;
>>+ unsigned int active = cpu_base->active_bases;
>>
>>- for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++, base++) {
>>+ for (; active; base++, active >>= 1) {
>> struct timerqueue_node *next;
>> struct hrtimer *timer;
>>
>>- next = timerqueue_getnext(&base->active);
>>- if (!next)
>>+ if (!(active & 0x01))
>> continue;
>>
>>+ next = timerqueue_getnext(&base->active);
>> timer = container_of(next, struct hrtimer, node);
>> expires = ktime_sub(hrtimer_get_expires(timer),
>>base->offset);
>> if (expires.tv64 < expires_next.tv64)
>>@@ -1206,17 +1206,16 @@ static void __run_hrtimer(struct hrtimer
>>
>> static void __hrtimer_run_queues(struct hrtimer_cpu_base *cpu_base,
ktime_t
>>now)
>> {
>>- int i;
>>+ struct hrtimer_clock_base *base = cpu_base->clock_base;
>>+ unsigned int active = cpu_base->active_bases;
>>
>>- for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
>>- struct hrtimer_clock_base *base;
>>+ for (; active; base++, active >>= 1) {
>> struct timerqueue_node *node;
>> ktime_t basenow;
>>
>>- if (!(cpu_base->active_bases & (1 << i)))
>>+ if (!(active & 0x01))
>> continue;
>>
>>- base = cpu_base->clock_base + i;
>> basenow = ktime_add(now, base->offset);
>>
>> while ((node = timerqueue_getnext(&base->active))) {
>>
next prev parent reply other threads:[~2015-04-20 11:16 UTC|newest]
Thread overview: 123+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-04-14 21:08 [patch 00/39] hrtimer/tick: Optimizations, cleanups and solutions for various issues Thomas Gleixner
2015-04-14 21:08 ` [patch 01/39] hrtimer: Update active_bases before calling hrtimer_force_reprogram() Thomas Gleixner
2015-04-14 21:08 ` [patch 02/39] hrtimer: Get rid of the resolution field in hrtimer_clock_base Thomas Gleixner
2015-04-15 6:29 ` Frans Klaver
2015-04-15 6:32 ` Frans Klaver
2015-04-20 8:34 ` Preeti U Murthy
2015-04-22 19:05 ` [tip:timers/core] " tip-bot for Thomas Gleixner
2015-04-14 21:08 ` [patch 03/39] net: sched: Use hrtimer_resolution instead of hrtimer_get_res() Thomas Gleixner
2015-04-16 16:04 ` David Miller
2015-04-22 19:05 ` [tip:timers/core] " tip-bot for Thomas Gleixner
2015-04-14 21:08 ` [patch 04/39] sound: " Thomas Gleixner
2015-04-16 8:07 ` Takashi Iwai
2015-04-16 9:08 ` Thomas Gleixner
2015-04-22 19:05 ` [tip:timers/core] " tip-bot for Thomas Gleixner
2015-04-14 21:08 ` [patch 05/39] hrtimer: Get rid " Thomas Gleixner
2015-04-22 19:05 ` [tip:timers/core] " tip-bot for Thomas Gleixner
2015-04-14 21:08 ` [patch 06/39] hrtimer: Make the statistics fields smaller Thomas Gleixner
2015-04-22 19:06 ` [tip:timers/core] " tip-bot for Thomas Gleixner
2015-04-14 21:08 ` [patch 07/39] hrtimer: Get rid of softirq time Thomas Gleixner
2015-04-22 19:06 ` [tip:timers/core] " tip-bot for Thomas Gleixner
2015-04-14 21:08 ` [patch 08/39] hrtimer: Make offset update smarter Thomas Gleixner
2015-04-20 9:30 ` Preeti U Murthy
2015-04-22 19:06 ` [tip:timers/core] " tip-bot for Thomas Gleixner
2015-04-14 21:08 ` [patch 09/39] hrtimer: Use a bits for various boolean indicators Thomas Gleixner
2015-04-22 19:07 ` [tip:timers/core] hrtimer: Use " tip-bot for Thomas Gleixner
2015-04-14 21:08 ` [patch 10/39] hrtimer: Use cpu_base->active_base for hotpath iterators Thomas Gleixner
2015-04-20 11:16 ` Preeti U Murthy [this message]
2015-04-21 11:53 ` Thomas Gleixner
2015-04-22 3:13 ` Preeti U Murthy
2015-04-22 19:07 ` [tip:timers/core] hrtimer: Use cpu_base-> active_base " tip-bot for Thomas Gleixner
2015-04-14 21:08 ` [patch 11/39] hrtimer: Cache line align the hrtimer cpu base Thomas Gleixner
2015-04-22 19:07 ` [tip:timers/core] " tip-bot for Thomas Gleixner
2015-04-14 21:08 ` [patch 12/39] hrtimer: Align the hrtimer clock bases as well Thomas Gleixner
2015-04-22 19:07 ` [tip:timers/core] " tip-bot for Thomas Gleixner
2015-04-14 21:08 ` [patch 13/39] timerqueue: Let timerqueue_add/del return information Thomas Gleixner
2015-04-22 19:08 ` [tip:timers/core] timerqueue: Let timerqueue_add/ del " tip-bot for Thomas Gleixner
2015-04-14 21:08 ` [patch 14/39] hrtimer: Make use of timerqueue_add/del return values Thomas Gleixner
2015-04-22 19:08 ` [tip:timers/core] hrtimer: Make use of timerqueue_add/ del " tip-bot for Thomas Gleixner
2015-04-14 21:08 ` [patch 15/39] hrtimer: Keep pointer to first timer and simplify __remove_hrtimer() Thomas Gleixner
2015-04-22 19:08 ` [tip:timers/core] " tip-bot for Thomas Gleixner
2015-04-14 21:08 ` [patch 16/39] hrtimer: Get rid of hrtimer softirq Thomas Gleixner
2015-04-22 19:09 ` [tip:timers/core] " tip-bot for Thomas Gleixner
2015-04-14 21:08 ` [patch 17/39] tick: sched: Remove hrtimer_active() checks Thomas Gleixner
2015-04-16 13:37 ` Frederic Weisbecker
2015-04-22 19:09 ` [tip:timers/core] " tip-bot for Thomas Gleixner
2015-04-14 21:08 ` [patch 18/39] tick: sched: Force tick interrupt and get rid of softirq magic Thomas Gleixner
2015-04-22 14:22 ` Frederic Weisbecker
2015-04-22 14:32 ` Thomas Gleixner
2015-04-23 11:47 ` Frederic Weisbecker
2015-04-23 13:07 ` Thomas Gleixner
2015-04-23 16:14 ` Frederic Weisbecker
2015-04-22 19:09 ` [tip:timers/core] " tip-bot for Thomas Gleixner
2015-04-14 21:08 ` [patch 19/39] tick: sched: Restructure code Thomas Gleixner
2015-04-22 19:09 ` [tip:timers/core] tick: Sched: " tip-bot for Thomas Gleixner
2015-04-14 21:08 ` [patch 20/39] tick: nohz: Rework next timer evaluation Thomas Gleixner
2015-04-16 16:42 ` Paul E. McKenney
2015-04-21 12:04 ` Thomas Gleixner
2015-04-22 19:10 ` [tip:timers/core] tick: Nohz: " tip-bot for Thomas Gleixner
2015-04-14 21:09 ` [patch 21/39] x86: perf: Use hrtimer_start() Thomas Gleixner
2015-04-22 19:10 ` [tip:timers/core] " tip-bot for Thomas Gleixner
2015-04-14 21:09 ` [patch 22/39] x86: perf: uncore: " Thomas Gleixner
2015-04-22 19:10 ` [tip:timers/core] " tip-bot for Thomas Gleixner
2015-04-14 21:09 ` [patch 23/39] perf: core: " Thomas Gleixner
2015-04-22 19:11 ` [tip:timers/core] " tip-bot for Thomas Gleixner
2015-04-14 21:09 ` [patch 24/39] sched: core: Use hrtimer_start[_expires]() Thomas Gleixner
2015-04-22 19:11 ` [tip:timers/core] " tip-bot for Thomas Gleixner
2015-04-14 21:09 ` [patch 25/39] sched: deadline: Use hrtimer_start() Thomas Gleixner
2015-04-22 19:11 ` [tip:timers/core] " tip-bot for Thomas Gleixner
2015-04-14 21:09 ` [patch 26/39] hrtimer: Get rid of __hrtimer_start_range_ns() Thomas Gleixner
2015-04-22 19:11 ` [tip:timers/core] " tip-bot for Thomas Gleixner
2015-04-14 21:09 ` [patch 27/39] hrtimer: Make hrtimer_start() a inline wrapper Thomas Gleixner
2015-04-22 19:12 ` [tip:timers/core] " tip-bot for Thomas Gleixner
2015-04-14 21:09 ` [patch 28/39] hrtimer: Remove bogus hrtimer_active() check Thomas Gleixner
2015-04-22 19:12 ` [tip:timers/core] " tip-bot for Thomas Gleixner
2015-04-14 21:09 ` [patch 29/39] hrtimer: Rmove " Thomas Gleixner
2015-04-22 19:12 ` [tip:timers/core] futex: Remove " tip-bot for Thomas Gleixner
2015-04-14 21:09 ` [patch 30/39] rtmutex: " Thomas Gleixner
2015-04-22 19:13 ` [tip:timers/core] " tip-bot for Thomas Gleixner
2015-04-14 21:09 ` [patch 31/39] net: core: pktgen: " Thomas Gleixner
2015-04-16 16:04 ` David Miller
2015-04-22 19:13 ` [tip:timers/core] net: core: pktgen: Remove bogus hrtimer_active( ) check tip-bot for Thomas Gleixner
2015-04-14 21:09 ` [patch 32/39] alarmtimer: Get rid of unused return value Thomas Gleixner
2015-04-22 19:13 ` [tip:timers/core] " tip-bot for Thomas Gleixner
2015-04-14 21:09 ` [patch 34/39] tick: broadcast-hrtimer: Remove overly clever return value abuse Thomas Gleixner
2015-04-17 10:33 ` Preeti U Murthy
2015-04-22 19:13 ` [tip:timers/core] " tip-bot for Thomas Gleixner
2015-04-14 21:09 ` [patch 35/39] hrtimer: Remove hrtimer_start() return value Thomas Gleixner
2015-04-22 19:14 ` [tip:timers/core] " tip-bot for Thomas Gleixner
2015-04-14 21:09 ` [patch 36/39] hrtimer: Avoid locking in hrtimer_cancel() if timer not active Thomas Gleixner
2015-04-22 19:14 ` [tip:timers/core] " tip-bot for Thomas Gleixner
2015-04-14 21:09 ` [patch 37/39] staging: ozwpan: Remove hrtimer_active() check Thomas Gleixner
2015-04-14 21:09 ` [patch 38/39] timer: Remove pointless return value of do_usleep_range() Thomas Gleixner
2015-04-22 19:14 ` [tip:timers/core] " tip-bot for Thomas Gleixner
2015-04-14 21:09 ` [patch 39/39] timer: Put usleep_range into the __sched section Thomas Gleixner
2015-04-22 19:14 ` [tip:timers/core] " tip-bot for Thomas Gleixner
[not found] ` <20150414203503.322172417@linutronix.de>
2015-04-14 21:38 ` [patch 33/39] power: reset: ltc2952: Remove bogus hrtimer_start() return value checks Frans Klaver
2015-04-30 15:49 ` Sebastian Reichel
-- strict thread matches above, loose matches on Subject: below --
2015-04-07 2:10 [PATCH V2 0/2] hrtimer: Iterate only over active clock-bases Viresh Kumar
2015-04-07 2:10 ` [PATCH V2 1/2] hrtimer: update '->active_bases' before calling hrtimer_force_reprogram() Viresh Kumar
2015-04-22 19:04 ` [tip:timers/core] hrtimer: Update active_bases " tip-bot for Viresh Kumar
2015-04-07 2:10 ` [PATCH V2 2/2] hrtimer: Iterate only over active clock-bases Viresh Kumar
2015-04-08 12:10 ` Peter Zijlstra
2015-04-08 20:11 ` Thomas Gleixner
2015-04-09 2:42 ` Viresh Kumar
2015-04-09 6:28 ` [PATCH] hrtimer: Replace cpu_base->active_bases with a direct check of the active list Ingo Molnar
2015-04-09 6:38 ` Ingo Molnar
2015-04-09 6:39 ` [PATCH] hrtimer: Only iterate over active bases in migrate_hrtimers() Ingo Molnar
2015-04-09 6:53 ` [PATCH] hrtimer: Replace timerqueue_getnext() uses with direct access to 'active.next' Ingo Molnar
2015-04-09 7:10 ` [PATCH] hrtimers: Use consistent variable names for timerqueue_node iterations Ingo Molnar
2015-04-09 6:57 ` [PATCH] hrtimer: Replace cpu_base->active_bases with a direct check of the active list Peter Zijlstra
2015-04-09 7:09 ` Ingo Molnar
2015-04-09 7:20 ` Ingo Molnar
2015-04-09 8:58 ` Thomas Gleixner
2015-04-09 8:58 ` Peter Zijlstra
2015-04-09 9:18 ` Thomas Gleixner
2015-04-09 9:31 ` Peter Zijlstra
2015-04-09 9:56 ` Thomas Gleixner
2015-04-13 5:53 ` Preeti U Murthy
2015-04-13 7:53 ` Thomas Gleixner
2015-04-09 8:03 ` Peter Zijlstra
2015-04-09 8:10 ` Ingo Molnar
2015-04-09 8:53 ` Thomas Gleixner
2015-04-09 9:18 ` Ingo Molnar
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