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/buffer.c | 2 -- 1 file changed, 2 deletions(-) (limited to 'fs/buffer.c') diff --git a/fs/buffer.c b/fs/buffer.c index 23f1f3a68077..373bb6292bdc 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -331,7 +331,6 @@ long do_fsync(struct file *file, int datasync) goto out; } - current->flags |= PF_SYNCWRITE; ret = filemap_fdatawrite(mapping); /* @@ -346,7 +345,6 @@ long do_fsync(struct file *file, int datasync) err = filemap_fdatawait(mapping); if (!ret) ret = err; - current->flags &= ~PF_SYNCWRITE; out: return ret; } -- cgit v1.2.3-59-g8ed1b