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
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20080312213255.GM27894@ZenIV.linux.org.uk \
--to=viro@zeniv.linux.org.uk \
--cc=jcpiza@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=riel@redhat.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.