From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33482) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XEFTe-0003gj-P6 for qemu-devel@nongnu.org; Mon, 04 Aug 2014 06:26:55 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XEFTZ-0004mL-RM for qemu-devel@nongnu.org; Mon, 04 Aug 2014 06:26:50 -0400 Received: from mx1.redhat.com ([209.132.183.28]:6272) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XEFTZ-0004mA-In for qemu-devel@nongnu.org; Mon, 04 Aug 2014 06:26:45 -0400 Date: Mon, 4 Aug 2014 11:26:39 +0100 From: Stefan Hajnoczi Message-ID: <20140804102639.GD5784@stefanha-thinkpad.redhat.com> References: <1406720388-18671-1-git-send-email-ming.lei@canonical.com> <1406720388-18671-11-git-send-email-ming.lei@canonical.com> <53D8FA63.60701@redhat.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="uxuisgdDHaNETlh8" Content-Disposition: inline In-Reply-To: Subject: Re: [Qemu-devel] [PATCH 10/15] linux-aio: increase max event to 256 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Ming Lei Cc: Kevin Wolf , Peter Maydell , Fam Zheng , "Michael S. Tsirkin" , qemu-devel , Paolo Bonzini --uxuisgdDHaNETlh8 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Jul 31, 2014 at 01:20:22AM +0800, Ming Lei wrote: > On Wed, Jul 30, 2014 at 10:00 PM, Paolo Bonzini wro= te: > > Il 30/07/2014 13:39, Ming Lei ha scritto: > >> This patch increases max event to 256 for the comming > >> virtio-blk multi virtqueue support. > >> > >> Signed-off-by: Ming Lei > >> --- > >> block/linux-aio.c | 2 +- > >> 1 file changed, 1 insertion(+), 1 deletion(-) > > > > What makes the new magic number less magic than the old one? >=20 > Just for supporting the coming multi virtqueue, otherwise it is > easy to trigger EAGAIN. >=20 > Or do you have better idea to figure out a non-magic number? The virtio-blk device knows how many requests can be in-flight at a time. laio_init() could take a size parameter. The messy thing is that the block layer is between the virtio-blk device and Linux AIO, so we'd need to pass that information down. Stefan --uxuisgdDHaNETlh8 Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQEcBAEBAgAGBQJT31/fAAoJEJykq7OBq3PI/G4H/R41vDx8dOm/Q15tk1mUkG/l 3VV5F0bY9KuaD7LW0feHH5FLvnd28nuYEQYTUditKEZVMDEdoGJgwq2mZ+FVWjBj doDKFRVn3+/467LZZz+zoGswn5D4dWxLcxZLHEFSMS/QFyU/AWExAjnOMxAi6c8b Z+hGKeejgC0F36V723/jbOXH6I1MOsi1HXZhW+Qvz3SL9ihd5tcYpTIIdMpEmHxD WS7LD2mNyQbC3WUYd7C4iEcKTNzMjYbbXAU2yyXMauLnaFdQ0D/4Bwq/ePic3AZp NnfJHj4xcM/zBZCMy1O7MpzVL8m9jt4ZJZgXwpJo4PtjHadZZW4ZdQRZwhFRpRw= =d7h6 -----END PGP SIGNATURE----- --uxuisgdDHaNETlh8--