From: Anton Blanchard <anton@samba.org>
To: Andi Kleen <ak@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>, linux-kernel@vger.kernel.org
Subject: Re: speed difference between using hard-linked and modular drives?
Date: Fri, 9 Nov 2001 11:05:32 +1100 [thread overview]
Message-ID: <20011109110532.B6822@krispykreme> (raw)
In-Reply-To: <Pine.LNX.4.33.0111081802380.15975-100000@localhost.localdomain.suse.lists.linux.kernel> <Pine.LNX.4.33.0111081836080.15975-100000@localhost.localdomain.suse.lists.linux.kernel> <p731yj8kgvw.fsf@amdsim2.suse.de>
In-Reply-To: <p731yj8kgvw.fsf@amdsim2.suse.de>
> > we should fix this by trying to allocate continuous physical memory if
> > possible, and fall back to vmalloc() only if this allocation fails.
>
> Check -aa. A patch to do that has been in there for some time now.
We also need a way to satisfy very large allocations for the hashes (eg
the pagecache hash). On a 32G machine we get awful performance on the
pagecache hash because we can only get an order 9 allocation out of
get_free_pages:
http://samba.org/~anton/linux/pagecache/pagecache_before.png
When switching to vmalloc the hash is large enough to be useful:
http://samba.org/~anton/linux/pagecache/pagecache_after.png
As pointed out by Davem and Ingo we should try and avoid vmalloc here
due to tlb trashing.
Anton
next prev parent reply other threads:[~2001-11-09 0:10 UTC|newest]
Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <Pine.LNX.4.33.0111081802380.15975-100000@localhost.localdomain.suse.lists.linux.kernel>
[not found] ` <Pine.LNX.4.33.0111081836080.15975-100000@localhost.localdomain.suse.lists.linux.kernel>
2001-11-08 23:00 ` speed difference between using hard-linked and modular drives? Andi Kleen
2001-11-09 0:05 ` Anton Blanchard [this message]
2001-11-09 5:45 ` Andi Kleen
2001-11-09 6:04 ` David S. Miller
2001-11-09 6:39 ` Andi Kleen
2001-11-09 6:54 ` Andrew Morton
2001-11-09 7:17 ` David S. Miller
2001-11-09 7:16 ` Andrew Morton
2001-11-09 7:24 ` David S. Miller
2001-11-09 8:21 ` Ingo Molnar
2001-11-09 7:35 ` Andrew Morton
2001-11-09 7:44 ` David S. Miller
2001-11-09 7:14 ` David S. Miller
2001-11-09 7:16 ` David S. Miller
2001-11-09 12:59 ` Alan Cox
2001-11-09 12:54 ` David S. Miller
2001-11-09 13:15 ` Philip Dodd
2001-11-09 13:26 ` David S. Miller
2001-11-09 20:45 ` Mike Fedyk
2001-11-09 13:17 ` Andi Kleen
2001-11-09 13:25 ` David S. Miller
2001-11-09 13:39 ` Andi Kleen
2001-11-09 13:41 ` David S. Miller
2001-11-10 5:20 ` Anton Blanchard
2001-11-10 4:56 ` Anton Blanchard
2001-11-10 5:09 ` Andi Kleen
2001-11-10 13:29 ` David S. Miller
2001-11-10 13:44 ` David S. Miller
2001-11-10 13:52 ` David S. Miller
2001-11-10 14:29 ` Numbers: ext2/ext3/reiser Performance (ext3 is slow) Oktay Akbal
2001-11-10 14:47 ` arjan
2001-11-10 17:41 ` Oktay Akbal
2001-11-10 17:56 ` Arjan van de Ven
2001-11-15 17:24 ` Stephen C. Tweedie
2001-11-12 16:59 ` [patch] arbitrary size memory allocator, memarea-2.4.15-D6 Ingo Molnar
2001-11-12 18:19 ` Jeff Garzik
2001-11-12 23:26 ` Ingo Molnar
2001-11-13 15:59 ` Riley Williams
2001-11-14 20:49 ` Tom Gall
2001-11-15 1:11 ` Anton Blanchard
2001-11-17 18:00 ` Eric W. Biederman
2001-11-17 18:00 ` Eric W. Biederman
2001-11-09 3:12 ` speed difference between using hard-linked and modular drives? Rusty Russell
2001-11-09 5:59 ` Andi Kleen
2001-11-09 11:16 ` Helge Hafting
2001-11-12 9:59 ` Rusty Russell
2001-11-12 23:23 ` David S. Miller
2001-11-12 23:14 ` Rusty Russell
2001-11-13 1:30 ` Mike Fedyk
2001-11-13 1:15 ` David Lang
2001-11-08 16:01 Roy Sigurd Karlsbakk
2001-11-08 17:02 ` Ingo Molnar
2001-11-08 17:37 ` Ingo Molnar
2001-11-08 23:59 ` Anton Blanchard
2001-11-09 5:11 ` Keith Owens
2001-11-10 3:35 ` Anton Blanchard
2001-11-10 7:26 ` Keith Owens
2001-11-08 17:53 ` Robert Love
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