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From: Michael Tokarev <mjt@tls.msk.ru>
To: Boaz Harrosh <bharrosh@panasas.com>
Cc: Andi Kleen <andi@firstfloor.org>, Michael Stiller <ms@2scale.net>,
	linux-kernel@vger.kernel.org
Subject: Re: howto boost write(2) performance?
Date: Tue, 09 Oct 2007 20:26:20 +0400	[thread overview]
Message-ID: <470BABAC.2030706@msgid.tls.msk.ru> (raw)
In-Reply-To: <470BA14C.90608@panasas.com>

Boaz Harrosh wrote:
[]
> 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.

What's the advantage of sg_io over O_DIRECT to the block device?
I think sg devices are being (slowly?) obsoleted since most stuff
which has been in sg now works over normal block device, no?
At least, I haven't seen any significant difference between
sg_dd and dd with oflag=direct.

Thanks.

/mjt

  reply	other threads:[~2007-10-09 16:26 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
2007-10-09 16:26     ` Michael Tokarev [this message]
2007-10-11 13:50   ` Michael Stiller
2007-10-17 22:19 ` Bill Davidsen

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