On Wed, Jul 10, 2013 at 04:12:36PM -0700, Paul Taysom wrote: > The following commit introduced a 10x regression for > syncing inodes in ext4 with relatime enabled where just > the atime had been modified. > > commit 4ea425b63a3dfeb7707fc7cc7161c11a51e871ed > Author: Jan Kara <jack@xxxxxxx> > Date: Tue Jul 3 16:45:34 2012 +0200 > vfs: Avoid unnecessary WB_SYNC_NONE writeback during sys_sync and reorder sync passes > > See also: http://www.kernelhub.org/?msg=93100&p=2 > > Fixed by putting back in the call to writeback_inodes_sb. > > I'll attach the test in a reply to this e-mail. > > The test starts by creating 512 files, syncing, reading one byte > from each of those files, syncing, and then deleting each file > and syncing. The time to do each sync is printed. The process > is then repeated for 1024 files and then the next power of > two up to 262144 files. > > Note, when running the test, the slow down doesn't always happen > but most of the tests will show a slow down. Can you please check if the patch attached to this mail: http://marc.info/?l=linux-kernel&m=137276874025813&w=2 Fixes your problem? Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
