From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:34298) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aarvm-0001LP-Vr for qemu-devel@nongnu.org; Tue, 01 Mar 2016 16:34:11 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aarvi-0007aY-TE for qemu-devel@nongnu.org; Tue, 01 Mar 2016 16:34:10 -0500 Received: from mx5-phx2.redhat.com ([209.132.183.37]:50598) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aarvi-0007aU-M5 for qemu-devel@nongnu.org; Tue, 01 Mar 2016 16:34:06 -0500 Date: Tue, 1 Mar 2016 16:34:04 -0500 (EST) From: Stefan Hajnoczi Message-ID: <1079134073.2531350.1456868044024.JavaMail.zimbra@redhat.com> In-Reply-To: References: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] qemu AIO worker threads change causes Guest OS hangup List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Huaicheng Li Cc: qemu-devel@nongnu.org ----- Original Message ----- > From: "Huaicheng Li" > I=E2=80=99m trying to add some latency conditionally to I/O requests (qem= u_paiocb, > from **IDE** disk emulation, **raw** image file). Paolo already covered the technical issue with what you're doing. Have you seen Linux Documentation/device-mapper/delay.txt? You could set up a loopback block device and put the device-mapper delay ta= rget on top to simulate latency. Stefan