From: "Mr. Berkley Shands" <berkley@cse.wustl.edu>
To: linux-kernel@vger.kernel.org
Subject: Fast patch for Severe I/O performance regression 2.6.6 to 2.6.7 or 2.6.8-rc3
Date: Fri, 06 Aug 2004 13:02:34 -0500 [thread overview]
Message-ID: <4113C7BA.6060608@cse.wustl.edu> (raw)
In-Reply-To: <20040805172531.GC17188@holomorphy.com>
in 2.6.8-rc3/mm/readahead.c line 475 (about label do_io:)
#if 0
ra->next_size = min(average , (unsigned long)max);
#endif
the comment for the above is here after an lseek. The lseek IS inside
the window, but the code will always
destroy the window and start again. The above patch corrects the
performance problem,
but it would be better to do nothing if the lseek is still within the
read ahead window.
berkley
next prev parent reply other threads:[~2004-08-06 18:10 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-08-05 17:02 Severe I/O performance regression 2.6.6 to 2.6.7 or 2.6.8-rc3 Mr. Berkley Shands
2004-08-05 17:25 ` William Lee Irwin III
2004-08-05 19:58 ` Mr. Berkley Shands
2004-08-05 20:46 ` William Lee Irwin III
2004-08-05 22:33 ` Marcelo Tosatti
2004-08-06 0:21 ` William Lee Irwin III
2004-08-06 2:09 ` Andy Isaacson
2004-08-06 2:27 ` William Lee Irwin III
2004-08-06 2:42 ` Andy Isaacson
2004-08-06 3:11 ` William Lee Irwin III
2004-08-06 8:33 ` Helge Hafting
2004-08-06 8:51 ` William Lee Irwin III
2004-08-06 18:02 ` Mr. Berkley Shands [this message]
2004-08-08 8:22 ` Fast patch for " Ram Pai
2004-08-16 20:30 ` [PATCH] " Ram Pai
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