From: Boaz Harrosh <bharrosh@panasas.com>
To: Andi Kleen <andi@firstfloor.org>
Cc: Michael Stiller <ms@2scale.net>, linux-kernel@vger.kernel.org
Subject: Re: howto boost write(2) performance?
Date: Tue, 09 Oct 2007 17:42:04 +0200 [thread overview]
Message-ID: <470BA14C.90608@panasas.com> (raw)
In-Reply-To: <p73odf849rq.fsf@bingen.suse.de>
On Tue, Oct 09 2007 at 16:56 +0200, Andi Kleen <andi@firstfloor.org> wrote:
> Michael Stiller <ms@2scale.net> writes:
>> The write(2) performance is not good enough, the writer threads take to
>> much time, and i ask you for ideas, howto to boost the write
>> performance.
>
> You could use an O_DIRECT write if the data is suitably aligned
> and your IO sizes are big enough (O_DIRECT is usually a loss
> on small IOs). It will also be synchronous, but if you do it
> from a separate thread anyways that should be fine.
>
> -Andi
If your target is a SCSI target you can gain up to 15% by using
sg. Search on the net for the "sg utils" package. The source code
of sg_dd and others are a grate example of how to do it.
Other wise O_DIRECT is your friend. Also look for asynchronous
I/O so you have a few pending IO buffers to keep the pipes full.
Boaz
next prev parent reply other threads:[~2007-10-09 15:42 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-10-09 13:50 howto boost write(2) performance? Michael Stiller
2007-10-09 10:25 ` Nick Piggin
2007-10-10 6:26 ` Michael Stiller
2007-10-09 14:19 ` Gustavo Chain
2007-10-09 14:56 ` Andi Kleen
2007-10-09 15:42 ` Boaz Harrosh [this message]
2007-10-09 16:26 ` Michael Tokarev
2007-10-11 13:50 ` Michael Stiller
2007-10-17 22:19 ` Bill Davidsen
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