From: Rik van Riel <riel@redhat.com>
To: rajman mekaco <rajman.mekaco@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
Paul Gortmaker <paul.gortmaker@windriver.com>,
Andrew Morton <akpm@linux-foundation.org>,
KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
Minchan Kim <minchan.kim@gmail.com>,
Christoph Lameter <cl@gentwo.org>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [PATCH 1/1] mlock: split the shmlock_user_lock spinlock into per user_struct spinlock
Date: Thu, 03 May 2012 16:27:54 -0400 [thread overview]
Message-ID: <4FA2EA4A.6040703@redhat.com> (raw)
In-Reply-To: <4FA2C946.60006@redhat.com>
On 05/03/2012 02:07 PM, Rik van Riel wrote:
> On 05/03/2012 01:34 PM, rajman mekaco wrote:
>> The user_shm_lock and user_shm_unlock functions use a single global
>> spinlock for protecting the user->locked_shm.
>>
>> This is an overhead for multiple CPUs calling this code even if they
>> are having different user_struct.
>>
>> Remove the global shmlock_user_lock and introduce and use a new
>> spinlock inside of the user_struct structure.
>>
>> Signed-off-by: rajman mekaco<rajman.mekaco@gmail.com>
>
> Reviewed-by: Rik van Riel <riel@redhat.com>
Hold this ... while the patch is correct, Peter raised
a valid concern about its usefulness, which should be
sorted out first.
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next prev parent reply other threads:[~2012-05-03 21:20 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-05-03 17:34 [PATCH 1/1] mlock: split the shmlock_user_lock spinlock into per user_struct spinlock rajman mekaco
2012-05-03 18:07 ` Rik van Riel
2012-05-03 20:27 ` Rik van Riel [this message]
2012-05-04 1:12 ` rajman mekaco
2012-05-10 13:34 ` rajman mekaco
2012-05-10 14:54 ` Rik van Riel
2012-05-10 15:39 ` rajman mekaco
2012-05-10 16:48 ` rajman mekaco
2012-05-10 22:30 ` Rik van Riel
2012-05-12 3:10 ` rajman mekaco
2012-05-03 19:31 ` Peter Zijlstra
2012-05-03 20:26 ` Rik van Riel
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