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From: Waiman Long <waiman.long@hp.com>
To: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@kernel.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Ingo Molnar <mingo@elte.hu>,
	Andrew Morton <akpm@linux-foundation.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Rik van Riel <riel@redhat.com>,
	Peter Hurley <peter@hurleysoftware.com>,
	Davidlohr Bueso <davidlohr.bueso@hp.com>,
	Alex Shi <alex.shi@intel.com>,
	Andrea Arcangeli <aarcange@redhat.com>,
	Matthew R Wilcox <matthew.r.wilcox@intel.com>,
	Dave Hansen <dave.hansen@intel.com>,
	Michel Lespinasse <walken@google.com>,
	Andi Kleen <andi@firstfloor.org>,
	"Chandramouleeswaran, Aswin" <aswin@hp.com>,
	"Norton, Scott J" <scott.norton@hp.com>
Subject: Re: [PATCH, v2] anon_vmas: Convert the rwsem to an rwlock_t
Date: Mon, 30 Sep 2013 15:35:08 -0400	[thread overview]
Message-ID: <5249D26C.8020208@hp.com> (raw)
In-Reply-To: <1380568987.3467.198.camel@schen9-DESK>

On 09/30/2013 03:23 PM, Tim Chen wrote:
> On Mon, 2013-09-30 at 20:14 +0200, Peter Zijlstra wrote:
>> On Mon, Sep 30, 2013 at 10:10:27AM -0700, Tim Chen wrote:
>>> Here's the exim workload data:
>>>
>>> rwsem improvment:
>>> Waimain's patch:        +2.0%
>>> Alex+Tim's patchset:    +4.8%
>>> Waiman+Alex+Tim:        +5.3%
>>>
>>> convert rwsem to rwlock_t for root anon_vma lock
>>> Ingo's patch		+11.7%
>>>
>> What happens if you stuff Waiman's qrwlock patches on top of that?
>> admittedly and oft mentioned in this thread, our current rwlock_t is
>> somewhat suboptimal under a number of conditions.
> I've tested with Waiman's qrwlock patches on top of Ingo's patches.
> It does not affect the throughput for exim and I still get
> about +11.7% throughput change (same as with Ingo's patch only).
>
> Tim
>

My qrwlock doesn't enable qrwlock by default. You have to use menuconfig 
to explicitly enable it. Have you done that when you build the test 
kernel? I am thinking of explicitly enabling it for x86 if the anon-vma 
lock is converted back to a rwlock.

-Longman

  reply	other threads:[~2013-09-30 19:35 UTC|newest]

Thread overview: 55+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-09-27 19:00 [PATCH] rwsem: reduce spinlock contention in wakeup code path Waiman Long
2013-09-27 19:28 ` Linus Torvalds
2013-09-27 19:39   ` Davidlohr Bueso
2013-09-27 21:49     ` Tim Chen
2013-09-28  6:45       ` Ingo Molnar
2013-09-28  7:41   ` Ingo Molnar
2013-09-28 18:55     ` Linus Torvalds
2013-09-28 19:13       ` Andi Kleen
2013-09-28 19:22         ` Linus Torvalds
2013-09-28 19:21       ` Ingo Molnar
2013-09-28 19:33         ` Linus Torvalds
2013-09-28 19:39           ` Ingo Molnar
2013-09-30 10:44           ` Peter Zijlstra
2013-09-30 16:13             ` Linus Torvalds
2013-09-30 16:41               ` Peter Zijlstra
2013-10-01  7:28                 ` Ingo Molnar
2013-10-01  8:09                   ` Peter Zijlstra
2013-10-01  8:25                     ` Ingo Molnar
2013-09-30 15:58           ` Waiman Long
2013-10-01  7:33             ` Ingo Molnar
2013-10-01 20:03               ` Waiman Long
2013-09-28 19:37         ` [PATCH] anon_vmas: Convert the rwsem to an rwlock_t Ingo Molnar
2013-09-28 19:43           ` Linus Torvalds
2013-09-28 19:46             ` Ingo Molnar
2013-09-28 19:52             ` [PATCH, v2] " Ingo Molnar
2013-09-30 11:00               ` Peter Zijlstra
2013-09-30 11:44               ` Peter Zijlstra
2013-09-30 17:03               ` Andrew Morton
2013-09-30 17:25                 ` Linus Torvalds
2013-09-30 17:10               ` Tim Chen
2013-09-30 18:14                 ` Peter Zijlstra
2013-09-30 19:23                   ` Tim Chen
2013-09-30 19:35                     ` Waiman Long [this message]
2013-09-30 19:47                       ` Tim Chen
2013-09-30 22:03                         ` Tim Chen
2013-10-01  2:41                         ` Waiman Long
2013-09-30  8:52           ` [PATCH] " Andrea Arcangeli
2013-09-30 14:40             ` Jerome Glisse
2013-09-30 16:26             ` Linus Torvalds
2013-09-30 19:16               ` Andrea Arcangeli
2013-09-30 18:21             ` Andi Kleen
2013-09-30 19:04               ` Jerome Glisse
2013-09-29 23:06       ` [PATCH] rwsem: reduce spinlock contention in wakeup code path Davidlohr Bueso
2013-09-29 23:26         ` Linus Torvalds
2013-09-30  0:40           ` Davidlohr Bueso
2013-09-30  0:51             ` Linus Torvalds
2013-09-30  6:57           ` Ingo Molnar
2013-09-30  1:11       ` Michel Lespinasse
2013-09-30  7:05         ` Ingo Molnar
2013-09-30 16:03           ` Waiman Long
2013-09-30 10:46       ` Peter Zijlstra
2013-10-01  7:48         ` Ingo Molnar
2013-10-01  8:10           ` Peter Zijlstra
2013-09-27 19:32 ` Peter Hurley
2013-09-28  0:46   ` Waiman Long

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