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 <hifumi.hisashi@oss.ntt.co.jp>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
This commit is contained in:
Hisashi Hifumi
2009-03-05 17:22:21 +09:00
committed by Mark Fasheh
parent 6ca497a83e
commit 1fca3a05ef

View File

@@ -1967,4 +1967,5 @@ const struct address_space_operations ocfs2_aops = {
.invalidatepage = ocfs2_invalidatepage,
.releasepage = ocfs2_releasepage,
.migratepage = buffer_migrate_page,
.is_partially_uptodate = block_is_partially_uptodate,
};