From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43724) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Xj8bY-00063x-03 for qemu-devel@nongnu.org; Tue, 28 Oct 2014 11:22:44 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Xj8bT-0006bl-II for qemu-devel@nongnu.org; Tue, 28 Oct 2014 11:22:39 -0400 Received: from mx1.redhat.com ([209.132.183.28]:35716) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Xj8bT-0006bf-B3 for qemu-devel@nongnu.org; Tue, 28 Oct 2014 11:22:35 -0400 Message-ID: <544FB4B1.6060404@redhat.com> Date: Tue, 28 Oct 2014 09:22:25 -0600 From: Eric Blake MIME-Version: 1.0 References: <1414256153-10148-1-git-send-email-pl@kamp.de> <1414256153-10148-4-git-send-email-pl@kamp.de> In-Reply-To: <1414256153-10148-4-git-send-email-pl@kamp.de> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="PVIp3X27cOAi02an7XHPgq7247bkPEIgW" Subject: Re: [Qemu-devel] [PATCHv3 3/6] block: add a knob to disable multiwrite_merge List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Lieven , qemu-devel@nongnu.org Cc: kwolf@redhat.com, famz@redhat.com, benoit@irqsave.net, armbru@redhat.com, mreitz@redhat.com, stefanha@redhat.com This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --PVIp3X27cOAi02an7XHPgq7247bkPEIgW Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On 10/25/2014 10:55 AM, Peter Lieven wrote: > The block layer silently merges write requests since > commit 40b4f539. This patch adds a knob to disable > this feature as there has been some discussion lately > if multiwrite is a good idea at all and as it falsifies > benchmarks. >=20 > Signed-off-by: Peter Lieven > Reviewed-by: Max Reitz > --- > +# @write-merging: #optional enable the merging of write requests > +# also known as multiwrite_merge (Since 2.2) > +# (default: true, but this might change in the future > +# depending on format/protocol/features used) > # > # Since: 1.7 > ## > @@ -1198,7 +1205,8 @@ > '*rerror': 'BlockdevOnError', > '*werror': 'BlockdevOnError', > '*read-only': 'bool', > - '*detect-zeroes': 'BlockdevDetectZeroesOptions' } } > + '*detect-zeroes': 'BlockdevDetectZeroesOptions', > + '*write-merging': 'bool' } } This says it is boolean... > +++ b/qmp-commands.hx > @@ -2104,6 +2104,7 @@ Each json-object contain the following: > - "iops_size": I/O size when limiting by iops (json-int) > - "detect_zeroes": detect and optimize zero writing (json-str= ing) > - Possible values: "off", "on", "unmap" > + - "write_merging": enable merging of write requests (json-boo= l) > - "image": the detail of the image, it is a json-object conta= ining > the following: > - "filename": image file name (json-string) > @@ -2181,6 +2182,7 @@ Example: > "iops_wr_max": 0, > "iops_size": 0, > "detect_zeroes": "on", > + "write_merging": "true", =2E..but this is not a JSON bool. s/"true"/true/ --=20 Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org --PVIp3X27cOAi02an7XHPgq7247bkPEIgW Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 Comment: Public key at http://people.redhat.com/eblake/eblake.gpg iQEcBAEBCAAGBQJUT7SxAAoJEKeha0olJ0Nq6rMH/1+xRjYYIvH1Vt0Wod7LG5eL j3hxUGUTRoUJVbh26XrkfRtZgsCK4zE6m94fdf/GOz0alPfnEMxjzg7BC8Br6sOn axUauVnEJYRFsFITtUsPLZSz0I84Yb3V58aBMqnXX7oeRaubXUcfeynLznjL+fOw /OkMQIwKwyArhrccIWFOY3zZXaEpEEk6NcksUztCySo8o1J53qzMkt8Y2995GME6 Dm4PuMHgA9/Ypu7tYdtB7M9djsePYw9yVwvYDlBoqScKbBmTe0fnBIxcGpDL5USK YVq2hdcWdp9xrpr4bUNT0sHCsj7nNgW95lTYcLUU15GbYX0POXIO0MYlKoxpoWI= =sGen -----END PGP SIGNATURE----- --PVIp3X27cOAi02an7XHPgq7247bkPEIgW--