mm: write_cache_pages optimise page cleaning
In write_cache_pages, if we get stuck behind another process that is cleaning pages, we will be forced to wait for them to finish, then perform our own writeout (if it was redirtied during the long wait), then wait for that. If a page under writeout is still clean, we can skip waiting for it (if we're part of a data integrity sync, we'll be waiting for all writeout pages afterwards, so we'll still be waiting for the other guy's write that's cleaned the page). Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Chris Mason <chris.mason@oracle.com> Cc: Dave Chinner <david@fromorbit.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
parent
5a3d5c9813
commit
515f4a037f
|
@ -945,11 +945,20 @@ continue_unlock:
|
|||
goto continue_unlock;
|
||||
}
|
||||
|
||||
if (wbc->sync_mode != WB_SYNC_NONE)
|
||||
wait_on_page_writeback(page);
|
||||
if (!PageDirty(page)) {
|
||||
/* someone wrote it for us */
|
||||
goto continue_unlock;
|
||||
}
|
||||
|
||||
if (PageWriteback(page) ||
|
||||
!clear_page_dirty_for_io(page))
|
||||
if (PageWriteback(page)) {
|
||||
if (wbc->sync_mode != WB_SYNC_NONE)
|
||||
wait_on_page_writeback(page);
|
||||
else
|
||||
goto continue_unlock;
|
||||
}
|
||||
|
||||
BUG_ON(PageWriteback(page));
|
||||
if (!clear_page_dirty_for_io(page))
|
||||
goto continue_unlock;
|
||||
|
||||
ret = (*writepage)(page, wbc, data);
|
||||
|
|
Loading…
Reference in New Issue