From: Phillip Susi <psusi@cfl.rr.com>
To: Jamie Lokier <jamie@shareable.org>
Cc: linux-fsdevel@vger.kernel.org,
Linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: readahead on directories
Date: Wed, 21 Apr 2010 10:57:00 -0400 [thread overview]
Message-ID: <4BCF123C.6010400@cfl.rr.com> (raw)
In-Reply-To: <20100421004434.GA27420@shareable.org>
On 4/20/2010 8:44 PM, Jamie Lokier wrote:
> readahead() doesn't make much sense on a directory - the offset and
> size aren't meaningful.
>
> But does plain opendir/readdir/closedir solve the problem?
No, since those are synchronous. I want to have readahead() queue up
reading the entire directory in the background to avoid blocking, and
get the queue filled with a bunch of requests that can be merged into
larger segments before being dispatched to the hardware.
I don't actually care to have the contents of the directories returned,
so readdir() does more than I need in that respect, and also it performs
a blocking read of one disk block at a time, which is horribly slow with
a cold cache.
next prev parent reply other threads:[~2010-04-21 14:57 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-04-19 15:51 readahead on directories Phillip Susi
2010-04-21 0:44 ` Jamie Lokier
2010-04-21 14:57 ` Phillip Susi [this message]
2010-04-21 16:12 ` Jamie Lokier
2010-04-21 18:10 ` Phillip Susi
2010-04-21 20:22 ` Jamie Lokier
2010-04-21 20:59 ` Phillip Susi
2010-04-21 22:06 ` Jamie Lokier
2010-04-22 7:01 ` Brad Boyer
2010-04-22 14:26 ` Phillip Susi
2010-04-22 17:53 ` Jamie Lokier
2010-04-22 19:23 ` Phillip Susi
2010-04-22 20:35 ` Jamie Lokier
2010-04-22 21:22 ` Phillip Susi
2010-04-22 22:43 ` Jamie Lokier
2010-04-23 4:13 ` Phillip Susi
2010-04-21 18:38 ` Evgeniy Polyakov
2010-04-21 18:51 ` Jamie Lokier
2010-04-21 18:56 ` Evgeniy Polyakov
2010-04-21 20:02 ` Jamie Lokier
2010-04-21 20:21 ` Evgeniy Polyakov
2010-04-21 20:39 ` Jamie Lokier
2010-04-21 19:23 ` Phillip Susi
2010-04-21 20:01 ` Jamie Lokier
2010-04-21 20:13 ` Phillip Susi
2010-04-21 20:37 ` Jamie Lokier
2010-05-07 13:38 ` unified page and buffer cache? (was: readahead on directories) Phillip Susi
2010-05-07 13:53 ` Matthew Wilcox
2010-05-07 15:45 ` unified page and buffer cache? Phillip Susi
2010-05-07 18:30 ` Matthew Wilcox
2010-05-08 0:50 ` Phillip Susi
2010-05-08 0:46 ` tytso
2010-05-08 0:54 ` Phillip Susi
2010-05-08 12:52 ` tytso
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