On Tue, Nov 20, 2012 at 02:42:48PM -0500, Jeff Moyer wrote:

Dave Chinner [off-list ref] writes:

quoted

And requeuing work from one workqueue to the next is something that
we can avoid.  We know at IO submission time (i.e.
xfs_vm_direct_io)) whether an fsync completion is going to be needed
during Io completion.  The ioend->io_needs_fsync flag can be set
then, and the first pass through xfs_finish_ioend() can queue it to
the correct workqueue.  i.e. it only needs to be queued if it's not
already an unwritten or append ioend and it needs an fsync.

As it is, all the data completion workqueues run the same completion
function so all you need to do is handle the fsync case at the end
of the existing processing - it's not an else case. i.e the end of
xfs_end_io() becomes:

	if (ioend->io_needs_fsync) {
		error = xfs_ioend_fsync(ioend);
		if (error)
			ioend->io_error = -error;
		goto done;
	}
done:
	xfs_destroy_ioend(ioend);

Works for me, that makes things simpler.

quoted

As it is, this code is going to change before these changes go in -
there's a nasty regression in the DIO code that I found this
afternoon that requires reworking this IO completion logic to
avoid. The patch will appear on the list soon....

I'm not on the xfs list, so if you haven't already sent it, mind Cc-ing
me?

http://oss.sgi.com/archives/xfs/2012-11/msg00493.html

First cut is here, but it will change a bit as review goes on...

quoted

quoted

--- a/fs/xfs/xfs_mount.h
+++ b/fs/xfs/xfs_mount.h

@@ -209,6 +209,7 @@ typedef struct xfs_mount {
 	struct workqueue_struct	*m_data_workqueue;
 	struct workqueue_struct	*m_unwritten_workqueue;
 	struct workqueue_struct	*m_cil_workqueue;
+	struct workqueue_struct *m_aio_blkdev_flush_wq;

	struct workqueue_struct *m_aio_fsync_wq;

For the record, m_aio_blkdev_flush_wq is the name you chose previously.
;-)

<cue Led Zeppelin>

It's been a long time since I read that patch....

:)

Cheers,

Dave....
-- 
Dave Chinner
david@fromorbit.com

_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs