From: "J. R. Okajima" <hooanon05@yahoo.co.jp>
To: Phillip Lougher <phillip@lougher.demon.co.uk>
Cc: linux-fsdevel@vger.kernel.org
Subject: Re: Q. cache in squashfs?
Date: Sun, 11 Jul 2010 14:55:14 +0900 [thread overview]
Message-ID: <6909.1278827714@jrobl> (raw)
In-Reply-To: <4C3930E9.8080905@lougher.demon.co.uk>
Phillip Lougher:
> In your first column (ext3 on squashfs), only a small amount of the
> overall cost is being accounted to the 'cat10' command, the bulk of
> the work is being accounted to the kernel 'loop1' thread and this isn't
> showing up. In the other cases (Squashfs only) the entire cost is being
> accounted to the 'cat10' command. The resulting results are therefore
> completely bogus, and incorrectly show higher CPU usage for Squashfs.
Ah, I forget about the kthread.
My question about CPU usage must be due to the kthread.
Also I could confirm that the sequential access pattern as you did shows
good performance.
While the very random access shows worse, it is a positive effect of
loopback caching as you wrote in your first reply.
Thank you very much.
J. R. Okajima
next prev parent reply other threads:[~2010-07-11 5:55 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-06-24 2:37 Q. cache in squashfs? J. R. Okajima
2010-07-08 3:57 ` Phillip Lougher
2010-07-08 6:08 ` J. R. Okajima
2010-07-09 7:53 ` J. R. Okajima
2010-07-09 10:32 ` Phillip Lougher
2010-07-09 10:55 ` Phillip Lougher
2010-07-10 5:07 ` J. R. Okajima
2010-07-10 5:08 ` J. R. Okajima
2010-07-11 2:48 ` Phillip Lougher
2010-07-11 5:55 ` J. R. Okajima [this message]
2010-07-11 9:38 ` [RFC 0/2] squashfs parallel decompression J. R. Okajima
2011-02-22 19:41 ` Phillip Susi
2011-02-23 3:23 ` Phillip Lougher
2010-07-11 9:38 ` [RFC 1/2] squashfs parallel decompression, early wait_on_buffer J. R. Okajima
2010-07-11 9:38 ` [RFC 2/2] squashfs parallel decompression, z_stream per cpu J. R. Okajima
2010-07-09 12:24 ` Q. cache in squashfs? J. R. Okajima
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