From: Wu Fengguang Date: Sat, 23 Apr 2011 17:26:07 +0000 (-0600) Subject: writeback: avoid extra sync work at enqueue time X-Git-Tag: next-20110726~3^2~18 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=e185dda89d69cde142b48059413a03561f41f78a;p=karo-tx-linux.git writeback: avoid extra sync work at enqueue time This removes writeback_control.wb_start and does more straightforward sync livelock prevention by setting .older_than_this to prevent extra inodes from being enqueued in the first place. Acked-by: Jan Kara Signed-off-by: Wu Fengguang --- diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index 565b1fd15be6..d0553f33fb50 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -544,15 +544,6 @@ static int writeback_sb_inodes(struct super_block *sb, struct bdi_writeback *wb, continue; } - /* - * Was this inode dirtied after sync_sb_inodes was called? - * This keeps sync from extra jobs and livelock. - */ - if (inode_dirtied_after(inode, wbc->wb_start)) { - spin_unlock(&inode->i_lock); - return 1; - } - __iget(inode); pages_skipped = wbc->pages_skipped; @@ -585,9 +576,6 @@ static void __writeback_inodes_wb(struct bdi_writeback *wb, { int ret = 0; - if (!wbc->wb_start) - wbc->wb_start = jiffies; /* livelock avoidance */ - while (!list_empty(&wb->b_io)) { struct inode *inode = wb_inode(wb->b_io.prev); struct super_block *sb = inode->i_sb; @@ -686,7 +674,9 @@ static long wb_writeback(struct bdi_writeback *wb, if (wbc.sync_mode == WB_SYNC_ALL || wbc.tagged_writepages) write_chunk = LONG_MAX; - wbc.wb_start = jiffies; /* livelock avoidance */ + oldest_jif = jiffies; + wbc.older_than_this = &oldest_jif; + spin_lock(&wb->list_lock); for (;;) { /* diff --git a/include/linux/writeback.h b/include/linux/writeback.h index c2d957fb38d3..d8e96a480850 100644 --- a/include/linux/writeback.h +++ b/include/linux/writeback.h @@ -26,9 +26,6 @@ struct writeback_control { enum writeback_sync_modes sync_mode; unsigned long *older_than_this; /* If !NULL, only write back inodes older than this */ - unsigned long wb_start; /* Time writeback_inodes_wb was - called. This is needed to avoid - extra jobs and livelock */ long nr_to_write; /* Write this many pages, and decrement this for each page written */ long pages_skipped; /* Pages which were not written */