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From: Pierre Ossman <drzeus-list@drzeus.cx>
To: LKML <linux-kernel@vger.kernel.org>,
	Russell King <rmk+lkml@arm.linux.org.uk>
Subject: MMC performance
Date: Mon, 11 Oct 2004 13:05:09 +0200	[thread overview]
Message-ID: <416A68E5.6080608@drzeus.cx> (raw)

I've added SGIO support to my driver now hoping that it would resolve 
the piss-poor performance I've been getting. Didn't do much difference 
though.

Read operations are fairly fast. It queues 8kB at a time. A bit small 
perhaps, but still decent.

Writing, however, only sends a single sector at a time. The queue 
process eats up half of the CPU time on my machine during a write. And 
since MMC cards have to clear a whole bunch of sectors before a write 
shouldn't you send as many sectors as possible to them?

Since I don't have another controller to compare with I don't really 
know if the problem is in my code, the MMC layer, the block layer or the 
filesystem.

I'm going to dig around a bit more but some pointers are welcome. At 
least which layer I should be looking at.

Rgds
Pierre

             reply	other threads:[~2004-10-11 11:05 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2004-10-11 11:05 Pierre Ossman [this message]
2004-10-11 12:19 ` MMC performance Russell King
2004-10-11 13:18   ` Alan Cox
2004-10-11 15:27     ` Pierre Ossman
2004-10-11 18:01       ` Pierre Ossman
2004-10-18 19:26         ` Pierre Ossman
2004-10-11 13:49   ` Pierre Ossman

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