From: Hisashi Hifumi Date: Thu, 5 Mar 2009 08:22:21 +0000 (+0900) Subject: ocfs2: Pagecache usage optimization on ocfs2 X-Git-Tag: v2.6.30-rc1~224^2~1 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1fca3a05ef2823830925dfb66711d6d920265a8d;p=pandora-kernel.git ocfs2: Pagecache usage optimization on ocfs2 A page can have multiple buffers and even if a page is not uptodate, some buffers can be uptodate on pagesize != blocksize environment. This aops checks that all buffers which correspond to a part of a file that we want to read are uptodate. If so, we do not have to issue actual read IO to HDD even if a page is not uptodate because the portion we want to read are uptodate. "block_is_partially_uptodate" function is already used by ext2/3/4. With the following patch random read/write mixed workloads or random read after random write workloads can be optimized and we can get performance improvement. Signed-off-by: Hisashi Hifumi Signed-off-by: Mark Fasheh --- Reading git-diff-tree failed