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From: Jens Axboe <axboe@kernel.dk>
To: Matthew Eaton <m.eaton82@gmail.com>
Cc: fio@vger.kernel.org
Subject: Re: Weird trim test results
Date: Thu, 25 Jul 2013 08:36:04 -0600	[thread overview]
Message-ID: <51F137D4.7000609@kernel.dk> (raw)
In-Reply-To: <CAF+0mvm8_89BhXRcs46d-AzyGunuVy3E32dcYi=kGThQkhAgfg@mail.gmail.com>

On 07/24/2013 02:22 PM, Matthew Eaton wrote:
> Hi guys,
> 
> I'm using this simple trim test on a raw SSD but getting very low
> performance.  Bandwidth seems to be tied to the block size.  Am I
> doing something wrong?

What kernel are you on? This looks like a missing unplug issue. If you
run a blktrace for a few seconds while the test is ongoing, the output
of blkparse should reveal if you are seeing timer unplugs.

-- 
Jens Axboe


  reply	other threads:[~2013-07-25 14:36 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-07-24 20:22 Weird trim test results Matthew Eaton
2013-07-25 14:36 ` Jens Axboe [this message]
2013-07-25 17:27   ` Matthew Eaton
2013-07-25 18:17     ` Jens Axboe
2013-07-25 19:19       ` Matthew Eaton
2013-07-25 19:19         ` Jens Axboe

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