From: Dave Chinner <david@fromorbit.com>
To: "Trenton D. Adams" <trenton.d.adams@gmail.com>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: Flash IO slow 1.5 MB/s
Date: Wed, 5 May 2010 10:14:58 +1000 [thread overview]
Message-ID: <20100505001458.GE8120@dastard> (raw)
In-Reply-To: <n2i9b1675091005032052wd935041ew5d96f145309af801@mail.gmail.com>
On Mon, May 03, 2010 at 09:52:44PM -0600, Trenton D. Adams wrote:
> If I mount my usb key with "sync" option, I get 500kb or less transfer
> speeds. If I use the gnome defaults, I get 60M+ for awhile, and then
> it continually drops over time, down to the 500kb/s again. Gnome
> defaults are...
>
> /dev/sdc1 on /media/FLASH type vfat
> (rw,nosuid,nodev,noatime,uhelper=hal,shortname=lower,flush,uid=500)
>
> I have done similar tests on both Rally2 64G usb stick and sandisk
> ultra (15M/s) SDHC 8G cards. I get lousy performance on both, unless
> I set dirty bytes. These are both FAT 32. But, as you can see below,
> 14 minutes to transfer less than a couple gigs is a little nutty. The
> 3 minutes is a lot nicer. I am using 2.6.33 with a patch from
> https://bugzilla.kernel.org/show_bug.cgi?id=15374
Perhaps it might be worth taking the writeback tracing code
from this patch series:
http://marc.info/?l=linux-fsdevel&m=127173141007222&w=2
And seeing what that tells you about how writeback is acting
differently....
Cheers,
Dave.
--
Dave Chinner
david@fromorbit.com
prev parent reply other threads:[~2010-05-05 0:15 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-05-04 3:52 Flash IO slow 1.5 MB/s Trenton D. Adams
2010-05-04 11:20 ` Theodore Tso
2010-05-04 18:05 ` Trenton D. Adams
2010-05-04 17:34 ` Paul Hartman
2010-05-04 18:00 ` Trenton D. Adams
2010-05-10 15:16 ` Paul Hartman
2010-05-05 0:14 ` Dave Chinner [this message]
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