From: Chris Mason <chris.mason@oracle.com>
To: Manfred Spraul <manfred@colorfullife.com>
Cc: Nick Piggin <npiggin@suse.de>,
zach.brown@oracle.com, jens.axboe@oracle.com,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/2] ipc semaphores: reduce ipc_lock contention in semtimedop
Date: Thu, 15 Apr 2010 12:34:55 -0400 [thread overview]
Message-ID: <20100415163455.GD3794@think> (raw)
In-Reply-To: <4BC73FC9.1090007@colorfullife.com>
On Thu, Apr 15, 2010 at 06:33:13PM +0200, Manfred Spraul wrote:
> On 04/14/2010 09:50 PM, Chris Mason wrote:
> >On a big system I saw about 4000 semaphores total. The database will
> >just allocate as many as it can into a single array and keep creating
> >arrays until it has all it needs.
> >
> What happens if SEMMSL is reduced (first entry in /proc/sys/kernel/sem)?
Performance improves slightly but the ipc lock is still at the top of the
profile ;)
-chris
next prev parent reply other threads:[~2010-04-15 16:36 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-04-12 18:49 [PATCH RFC] Optimize semtimedop Chris Mason
2010-04-12 18:49 ` [PATCH 1/2] ipc semaphores: reduce ipc_lock contention in semtimedop Chris Mason
2010-04-13 17:15 ` Manfred Spraul
2010-04-13 17:39 ` Chris Mason
2010-04-13 18:09 ` Nick Piggin
2010-04-13 18:19 ` Chris Mason
2010-04-13 18:57 ` Nick Piggin
2010-04-13 19:01 ` Chris Mason
2010-04-13 19:25 ` Nick Piggin
2010-04-13 19:38 ` Chris Mason
2010-04-13 20:05 ` Nick Piggin
2010-05-16 16:57 ` Manfred Spraul
2010-05-16 22:40 ` Chris Mason
2010-05-17 7:20 ` Nick Piggin
2010-04-14 16:16 ` Manfred Spraul
2010-04-14 17:33 ` Chris Mason
2010-04-14 19:11 ` Manfred Spraul
2010-04-14 19:50 ` Chris Mason
2010-04-15 16:33 ` Manfred Spraul
2010-04-15 16:34 ` Chris Mason [this message]
2010-04-13 18:24 ` Zach Brown
2010-04-16 11:26 ` Manfred Spraul
2010-04-16 11:45 ` Chris Mason
2010-04-12 18:49 ` [PATCH 2/2] ipc semaphores: order wakeups based on waiter CPU Chris Mason
2010-04-17 10:24 ` Manfred Spraul
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