tree 35636edac6ed01baf301f3aca96f090caae82c9d
parent b813e931b4c8235bb42e301096ea97dbdee3e8fe
author Jan Kara <jack@suse.cz> 1178488165 -0700
committer Linus Torvalds <torvalds@woody.linux-foundation.org> 1178565172 -0700

readahead: improve heuristic detecting sequential reads

Introduce ra.offset and store in it an offset where the previous read
ended.  This way we can detect whether reads are really sequential (and
thus we should not mark the page as accessed repeatedly) or whether they
are random and just happen to be in the same page (and the page should
really be marked accessed again).

Signed-off-by: Jan Kara <jack@suse.cz>
Acked-by: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: WU Fengguang <wfg@mail.ustc.edu.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>