From b31dc66a54ad986b6b73bdc49c8efc17cbad1833 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Tue, 13 Jun 2006 08:26:10 +0200 Subject: [PATCH] Kill PF_SYNCWRITE flag A process flag to indicate whether we are doing sync io is incredibly ugly. It also causes performance problems when one does a lot of async io and then proceeds to sync it. Part of the io will go out as async, and the other part as sync. This causes a disconnect between the previously submitted io and the synced io. For io schedulers such as CFQ, this will cause us lost merges and suboptimal behaviour in scheduling. Remove PF_SYNCWRITE completely from the fsync/msync paths, and let the O_DIRECT path just directly indicate that the writes are sync by using WRITE_SYNC instead. Signed-off-by: Jens Axboe --- fs/fs-writeback.c | 2 -- 1 file changed, 2 deletions(-) (limited to 'fs/fs-writeback.c') diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index 6db95cf3aaa..031b27a4bc9 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -623,7 +623,6 @@ int generic_osync_inode(struct inode *inode, struct address_space *mapping, int int need_write_inode_now = 0; int err2; - current->flags |= PF_SYNCWRITE; if (what & OSYNC_DATA) err = filemap_fdatawrite(mapping); if (what & (OSYNC_METADATA|OSYNC_DATA)) { @@ -636,7 +635,6 @@ int generic_osync_inode(struct inode *inode, struct address_space *mapping, int if (!err) err = err2; } - current->flags &= ~PF_SYNCWRITE; spin_lock(&inode_lock); if ((inode->i_state & I_DIRTY) && -- cgit v1.2.3