On Wed, Sep 06, 2017 at 04:38:06PM +0200, David Sterba wrote: > On Thu, Aug 24, 2017 at 06:19:48PM -0600, Liu Bo wrote: > > This updates btrfs to use the helper wbc_to_write_flags which has been > > applied in ext4/xfs/f2fs/block. > > Added in commit 7637241e651ec36e4094 in 11/2016, I wonder why btrfs > wasn't been changed as well as it uses the same code patterns as the > other filesystems. >
/me is curious, too. > > Please note that, with this, btrfs's dirty pages written by a > > writeback job will carry the flag REQ_BACKGROUND, which is currently > > used by writeback-throttle to determine whether it should go to get a > > request or wait. > > Which in my understanding of the WBT behaviour is what we want, right? > Yes, it gives a hint to WBT whether it should wait or not. > > Signed-off-by: Liu Bo <bo.li....@oracle.com> > > Reviewed-by: David Sterba <dste...@suse.com> > > I'm still expecting some surprises (== performance drop) from the recent > WBT changes, as we still may miss some request flags, but more subtle > than eg. the superblock REQ_ tags. Looks like this is the only missing flag I could find, the missing REQ_META (in another patch) doesn't have an impact on WBT. thanks, -liubo -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
