From: Al Viro <viro@ZenIV.linux.org.uk>
To: Rik van Riel <riel@redhat.com>
Cc: "J.C. Pizarro" <jcpiza@gmail.com>, LKML <linux-kernel@vger.kernel.org>
Subject: Re: linux+glibc memory allocator, poor performance
Date: Wed, 12 Mar 2008 21:32:55 +0000 [thread overview]
Message-ID: <20080312213255.GM27894@ZenIV.linux.org.uk> (raw)
In-Reply-To: <20080312172221.6b6dba95@bree.surriel.com>
On Wed, Mar 12, 2008 at 05:22:21PM -0400, Rik van Riel wrote:
> On Wed, 12 Mar 2008 21:09:04 +0100
> "J.C. Pizarro" <jcpiza@gmail.com> wrote:
>
> > Assume a SMP system that has 8 CPUs. The main problem of requesting
> > pages is the BKL (Big Kernel Lock) in this SMP system used for mutual
> > exclusion of the shared resource (the memory).
> >
> > To solve this major problem, i propose you freely to allocate 8 local caches
> > of (e.g.) 2 MiB each CPU (total 2MiB x 8 CPUs = 16 MiB) acting as
> > 8 producer buffers for globally many consumer tasks (e.g. >= 20).
> >
> > When the some producer buffer is empty then it does unfrequently BKL to
> > allocate another 2 MiB more from the shared resource (the memory).
>
> You really should read the source code before proposing ideas.
>
> The kernel has done roughly what you describe since a little before
> 2.6.0.
ITYM a little before 2.4.0, and even prior to that it hadn't been under BKL.
next prev parent reply other threads:[~2008-03-12 21:33 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-03-12 20:09 linux+glibc memory allocator, poor performance J.C. Pizarro
2008-03-12 21:12 ` Al Viro
2008-03-13 5:57 ` David Newall
2008-03-13 6:12 ` Mike Galbraith
2008-03-13 6:22 ` David Newall
2008-03-13 7:38 ` Christoph Hellwig
2008-03-13 11:02 ` David Newall
2008-03-13 9:10 ` Pekka Enberg
2008-03-13 11:04 ` David Newall
2008-03-13 12:10 ` Alan Cox
2008-03-13 12:48 ` Pekka Enberg
2008-03-13 13:55 ` J.C. Pizarro
2008-03-13 19:40 ` David Newall
2008-03-13 20:05 ` Pekka Enberg
2008-03-13 22:50 ` Al Viro
2008-03-14 12:11 ` Stephen Clark
2008-03-14 6:05 ` Willy Tarreau
2008-03-13 10:50 ` David Newall
2008-03-13 12:23 ` J.C. Pizarro
2008-03-12 21:22 ` Rik van Riel
2008-03-12 21:32 ` Al Viro [this message]
-- strict thread matches above, loose matches on Subject: below --
2008-03-12 18:14 Xose Vazquez Perez
2008-03-17 18:36 ` Xose Vazquez Perez
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