From mboxrd@z Thu Jan  1 00:00:00 1970
From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Subject: Re: Fwd: xentop reporting zero written sectors
Date: Mon, 10 Oct 2011 12:31:29 -0400
Message-ID: <20111010163129.GF28646@phenom.oracle.com>
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To: Andy Burns <xen.lists@burns.me.uk>
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On Mon, Oct 10, 2011 at 04:16:04PM +0100, Andy Burns wrote:
> No response in xen-users, asking developers ....
>=20
> ---------- Forwarded message ----------
>=20
> Just moving a chunk of files from one filesysstem on xvba to another
> on xvdb, and was monitoring with xentop as it was taking longer than
> expected.
>=20
> The VBD_RD =A0and VBD_WR counters were both clocking-up as expected, as
> was the VBD_RSECT counter, but the VBD_WSECT counter was stuck on
> zero, I toggled on the individual VBD device counters and these showed
> the same (with the RD and WR counters correctly split between my
> source and destination disks)

Huh. Imagine that!
>=20
> Is this a long standing "feature" that I've never noticed before or a
> problem that should be reported?

Must be a feature. We would never write code with bugs. Never :-)

I think this new "feature" below will fix it for you:


diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkb=
ack/blkback.c
index 0bd7143..3e2ca68 100644
--- a/drivers/block/xen-blkback/blkback.c
+++ b/drivers/block/xen-blkback/blkback.c
@@ -778,7 +778,7 @@ static int dispatch_rw_block_io(struct xen_blkif *blk=
if,
=20
 	if (operation =3D=3D READ)
 		blkif->st_rd_sect +=3D preq.nr_sects;
-	else if (operation =3D=3D WRITE || operation =3D=3D WRITE_FLUSH)
+	else if (operation =3D=3D WRITE_ODIRECT || operation =3D=3D WRITE_FLUSH=
)
 		blkif->st_wr_sect +=3D preq.nr_sects;
=20
 	return 0;


Thanks for reporting it!