From: Mike Galbraith <bitbucket@online.de>
To: Rik van Riel <riel@redhat.com>
Cc: linux-kernel@vger.kernel.org, aquini@redhat.com,
walken@google.com, eric.dumazet@gmail.com, lwoodman@redhat.com,
jeremy@goop.org, Jan Beulich <JBeulich@novell.com>,
knoel@redhat.com, chegu_vinod@hp.com,
raghavendra.kt@linux.vnet.ibm.com, mingo@redhat.com
Subject: Re: [PATCH 0/5] x86,smp: make ticket spinlock proportional backoff w/ auto tuning
Date: Thu, 10 Jan 2013 16:19:42 +0100 [thread overview]
Message-ID: <1357831182.5841.21.camel@marge.simpson.net> (raw)
In-Reply-To: <20130108172632.1126898a@annuminas.surriel.com>
On Tue, 2013-01-08 at 17:26 -0500, Rik van Riel wrote:
> Please let me know if you manage to break this code in any way,
> so I can fix it...
I didn't break it, but did let it play with rq->lock contention. Using
cyclictest -Smp99 -i 100 -d 0, with 3 rt tasks for pull_rt_task() to
pull around appears to have been a ~dead heat.
3.6.11 3.6.11-spinlock
PerfTop: 78852 irqs/sec kernel:96.4% exact: 0.0% [1000Hz cycles], (all, 80 CPUs)
-------------------------------------------------------------------------------------------------
samples pcnt function samples pcnt function
_______ _____ ___________________________ _______ _____ ___________________________
468341.00 52.0% cpupri_set 471786.00 52.0% cpupri_set
110259.00 12.2% _raw_spin_lock 88963.00 9.8% ticket_spin_lock_wait
78863.00 8.8% native_write_msr_safe 77109.00 8.5% native_write_msr_safe
42882.00 4.8% __schedule 48858.00 5.4% native_write_cr0
40930.00 4.5% native_write_cr0 47038.00 5.2% __schedule
13718.00 1.5% finish_task_switch 24775.00 2.7% _raw_spin_lock
13188.00 1.5% plist_del 13117.00 1.4% plist_del
13078.00 1.5% _raw_spin_lock_irqsave 12372.00 1.4% ttwu_do_wakeup
12083.00 1.3% ttwu_do_wakeup 11553.00 1.3% _raw_spin_lock_irqsave
8359.00 0.9% pull_rt_task 8186.00 0.9% pull_rt_task
6979.00 0.8% apic_timer_interrupt 7989.00 0.9% finish_task_switch
4623.00 0.5% __enqueue_rt_entity 6430.00 0.7% apic_timer_interrupt
3961.00 0.4% resched_task 4721.00 0.5% resched_task
3942.00 0.4% __switch_to 4109.00 0.5% __switch_to
3128.00 0.3% _raw_spin_trylock 2917.00 0.3% rcu_idle_exit_common
3081.00 0.3% __tick_nohz_idle_enter 2897.00 0.3% __local_bh_enable
2561.00 0.3% update_curr_rt 2873.00 0.3% _raw_spin_trylock
2385.00 0.3% _raw_spin_lock_irq 2674.00 0.3% __enqueue_rt_entity
2190.00 0.2% __local_bh_enable 2434.00 0.3% update_curr_rt
1904.00 0.2% rcu_idle_exit_common 2161.00 0.2% hrtimer_interrupt
1870.00 0.2% clockevents_program_event 2106.00 0.2% ktime_get_update_offsets
1828.00 0.2% hrtimer_interrupt 1766.00 0.2% tick_nohz_idle_exit
1741.00 0.2% do_nanosleep 1608.00 0.2% __tick_nohz_idle_enter
1681.00 0.2% sys_clock_nanosleep 1437.00 0.2% do_nanosleep
1639.00 0.2% pick_next_task_rt 1428.00 0.2% hrtimer_init
1630.00 0.2% pick_next_task_stop 1320.00 0.1% sched_clock_idle_sleep_event
1535.00 0.2% _raw_spin_unlock_irqrestore 1290.00 0.1% sys_clock_nanosleep
next prev parent reply other threads:[~2013-01-10 15:20 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-01-08 22:26 Rik van Riel
2013-01-08 22:30 ` [PATCH 3/5] x86,smp: auto tune spinlock backoff delay factor Rik van Riel
2013-01-10 3:13 ` Rafael Aquini
2013-01-10 12:49 ` Michel Lespinasse
2013-01-08 22:31 ` [PATCH 4/5] x86,smp: keep spinlock delay values per hashed spinlock address Rik van Riel
2013-01-10 3:14 ` Rafael Aquini
2013-01-10 13:01 ` Michel Lespinasse
2013-01-10 13:05 ` Rik van Riel
2013-01-10 13:15 ` Michel Lespinasse
2013-01-08 22:32 ` [DEBUG PATCH 5/5] x86,smp: add debugging code to track spinlock delay value Rik van Riel
2013-01-08 22:32 ` [PATCH 2/5] x86,smp: proportional backoff for ticket spinlocks Rik van Riel
2013-01-08 22:50 ` Eric Dumazet
2013-01-08 22:54 ` Rik van Riel
2013-01-10 2:30 ` Rafael Aquini
2013-01-08 22:32 ` [PATCH 1/5] x86,smp: move waiting on contended ticket lock out of line Rik van Riel
2013-01-08 22:43 ` Eric Dumazet
2013-01-10 17:38 ` Raghavendra K T
2013-01-09 12:50 ` [PATCH 0/5] x86,smp: make ticket spinlock proportional backoff w/ auto tuning Raghavendra K T
2013-01-10 2:27 ` Rafael Aquini
2013-01-10 17:36 ` Raghavendra K T
2013-01-11 20:11 ` Rik van Riel
2013-01-13 18:07 ` Raghavendra K T
2013-01-10 15:19 ` Mike Galbraith [this message]
2013-01-10 15:31 ` Rik van Riel
2013-01-10 19:30 ` Mike Galbraith
2013-01-24 13:28 ` Ingo Molnar
2013-01-10 22:24 ` Chegu Vinod
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