From: Andrea Arcangeli <andrea@suse.de>
To: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Dan Kegel <dank@kegel.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: O_DIRECT please; Sybase 12.5
Date: Thu, 5 Jul 2001 15:59:42 +0200 [thread overview]
Message-ID: <20010705155942.P17051@athlon.random> (raw)
In-Reply-To: <3B3C4CB4.6B3D2B2F@kegel.com> <E15Fuul-0008SJ-00@the-village.bc.nu>
In-Reply-To: <E15Fuul-0008SJ-00@the-village.bc.nu>; from alan@lxorguk.ukuu.org.uk on Fri, Jun 29, 2001 at 10:50:15AM +0100
On Fri, Jun 29, 2001 at 10:50:15AM +0100, Alan Cox wrote:
> > the boss say "If Linux makes Sybase go through the page cache on
> > reads, maybe we'll just have to switch to Solaris. That's
> > a serious performance problem."
>
> Thats something you'd have to benchmark. It depends on a very large number
> of factors including whether the database uses mmap, the average I/O size
> and the like
correct, here the benchmarks:
http://boudicca.tux.org/hypermail/linux-kernel/2001week17/1175.html
http://boudicca.tux.org/hypermail/linux-kernel/2001week17/att-1175/01-directio.png
of course the huge improvement is also because of broken VM in the
buffered-io case.
Andrea
next prev parent reply other threads:[~2001-07-05 14:00 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2001-06-29 9:39 O_DIRECT please; Sybase 12.5 Dan Kegel
2001-06-29 9:50 ` Alan Cox
2001-06-29 10:16 ` Dan Kegel
2001-06-29 12:49 ` Mike Harrold
2001-07-05 13:59 ` Andrea Arcangeli [this message]
2001-06-29 15:23 ` Steve Lord
2001-07-03 9:42 ` Stephen C. Tweedie
2001-07-03 15:10 ` Daryll Strauss
2001-07-03 15:48 ` Stephen C. Tweedie
2001-07-05 13:53 ` Andrea Arcangeli
2001-07-05 14:28 ` Andrew Morton
2001-07-05 14:37 ` Andrea Arcangeli
2001-07-05 15:06 ` Andrew Morton
2001-07-06 0:25 ` Keith Owens
[not found] <3B3C4CB4.6B3D2B2F@kegel.com.suse.lists.linux.kernel>
2001-06-29 10:42 ` Andi Kleen
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