From 1fca3a05ef2823830925dfb66711d6d920265a8d Mon Sep 17 00:00:00 2001 From: Hisashi Hifumi Date: Thu, 5 Mar 2009 17:22:21 +0900 Subject: [PATCH] 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 --- fs/ocfs2/aops.c | 23 ++++++++++++----------- 1 file changed, 12 insertions(+), 11 deletions(-) diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c index 8e1709a679b..b2c52b3a148 100644 --- a/fs/ocfs2/aops.c +++ b/fs/ocfs2/aops.c @@ -1956,15 +1956,16 @@ static int ocfs2_write_end(struct file *file, struct address_space *mapping, } const struct address_space_operations ocfs2_aops = { - .readpage = ocfs2_readpage, - .readpages = ocfs2_readpages, - .writepage = ocfs2_writepage, - .write_begin = ocfs2_write_begin, - .write_end = ocfs2_write_end, - .bmap = ocfs2_bmap, - .sync_page = block_sync_page, - .direct_IO = ocfs2_direct_IO, - .invalidatepage = ocfs2_invalidatepage, - .releasepage = ocfs2_releasepage, - .migratepage = buffer_migrate_page, + .readpage = ocfs2_readpage, + .readpages = ocfs2_readpages, + .writepage = ocfs2_writepage, + .write_begin = ocfs2_write_begin, + .write_end = ocfs2_write_end, + .bmap = ocfs2_bmap, + .sync_page = block_sync_page, + .direct_IO = ocfs2_direct_IO, + .invalidatepage = ocfs2_invalidatepage, + .releasepage = ocfs2_releasepage, + .migratepage = buffer_migrate_page, + .is_partially_uptodate = block_is_partially_uptodate, };