From: Jens Axboe <jens.axboe@oracle.com>
To: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org
Cc: chris.mason@oracle.com, hch@infradead.org, tytso@mit.edu,
akpm@linux-foundation.org, jack@suse.cz,
trond.myklebust@fys.uio.no, Nick Piggin <npiggin@suse.de>,
Jens Axboe <jens.axboe@oracle.com>
Subject: [PATCH 13/16] writeback: remove smp_mb(), it's not needed with list_add_tail_rcu()
Date: Wed, 16 Sep 2009 15:24:51 +0200 [thread overview]
Message-ID: <1253107494-20160-14-git-send-email-jens.axboe@oracle.com> (raw)
In-Reply-To: <1253107494-20160-1-git-send-email-jens.axboe@oracle.com>
From: Nick Piggin <npiggin@suse.de>
list_add_tail_rcu contains required barriers.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
---
fs/fs-writeback.c | 6 +++---
1 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index 3475775..59c99e7 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -151,10 +151,10 @@ static void bdi_queue_work(struct backing_dev_info *bdi, struct bdi_work *work)
BUG_ON(!bdi->wb_cnt);
/*
- * Make sure stores are seen before it appears on the list
+ * list_add_tail_rcu() contains the necessary barriers to
+ * make sure the above stores are seen before the item is
+ * noticed on the list
*/
- smp_mb();
-
spin_lock(&bdi->wb_lock);
list_add_tail_rcu(&work->list, &bdi->work_list);
spin_unlock(&bdi->wb_lock);
--
1.6.4.1.207.g68ea
next prev parent reply other threads:[~2009-09-16 13:24 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-09-16 13:24 [PATCH 0/16] Post merge per-bdi writeback patches v4 Jens Axboe
2009-09-16 13:24 ` [PATCH 01/16] fs: remove bdev->bd_inode_backing_dev_info Jens Axboe
2009-09-16 13:24 ` [PATCH 02/16] writeback: get rid of wbc->for_writepages Jens Axboe
2009-09-16 13:24 ` [PATCH 03/16] writeback: merely wakeup flusher thread if work allocation fails for WB_SYNC_NONE Jens Axboe
2009-09-16 13:24 ` [PATCH 04/16] writeback: make wb_writeback() take an argument structure Jens Axboe
2009-09-16 13:32 ` Jan Kara
2009-09-16 13:24 ` [PATCH 05/16] fs: Assign bdi in super_block Jens Axboe
2009-09-16 13:34 ` Jan Kara
2009-09-16 13:24 ` [PATCH 06/16] writeback: only use bdi_writeback_all() for WB_SYNC_NONE writeout Jens Axboe
2009-09-16 13:24 ` [PATCH 07/16] writeback: use RCU to protect bdi_list Jens Axboe
2009-09-16 13:24 ` [PATCH 08/16] writeback: inline allocation failure handling in bdi_alloc_queue_work() Jens Axboe
2009-09-16 13:24 ` [PATCH 09/16] writeback: separate starting of sync vs opportunistic writeback Jens Axboe
2009-09-16 13:36 ` Jan Kara
2009-09-16 13:24 ` [PATCH 10/16] writeback: splice dirty inode entries to default bdi on bdi_destroy() Jens Axboe
2009-09-16 13:43 ` Jan Kara
2009-09-16 18:29 ` Jens Axboe
2009-09-17 9:22 ` Jan Kara
2009-09-16 13:24 ` [PATCH 11/16] writeback: add comments to bdi_work structure Jens Axboe
2009-09-16 13:24 ` [PATCH 12/16] writeback: use schedule_timeout_interruptible() Jens Axboe
2009-09-16 13:24 ` Jens Axboe [this message]
2009-09-16 13:24 ` [PATCH 14/16] writeback: improve scalability of bdi writeback work queues Jens Axboe
2009-09-16 13:24 ` [PATCH 15/16] writeback: Fix bdi use after free in wb_work_complete() Jens Axboe
2009-09-16 13:24 ` [PATCH 16/16] writeback: fix possible bdi writeback refcounting problem Jens Axboe
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