From mboxrd@z Thu Jan 1 00:00:00 1970 From: Martin Mailand Subject: Re: virtio-blk performance regression and qemu-kvm Date: Tue, 28 Feb 2012 18:15:27 +0100 Message-ID: <4F4D0BAF.2020508@tuxadero.com> References: <20120210143639.GA17883@gmail.com> <20120221155725.GA950@gmail.com> <20120222164840.GA8517@gmail.com> <4F4D035A.60107@tuxadero.com> Reply-To: martin@tuxadero.com Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Dongsu Park , qemu-devel@nongnu.org, kvm@vger.kernel.org To: Stefan Hajnoczi Return-path: Received: from einhorn.in-berlin.de ([192.109.42.8]:45679 "EHLO einhorn.in-berlin.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755082Ab2B1RPb (ORCPT ); Tue, 28 Feb 2012 12:15:31 -0500 In-Reply-To: Sender: kvm-owner@vger.kernel.org List-ID: Hi Stefan, I was bisecting qemu-kvm.git. git remote show origin * remote origin Fetch URL: git://git.kernel.org/pub/scm/virt/kvm/qemu-kvm.git Push URL: git://git.kernel.org/pub/scm/virt/kvm/qemu-kvm.git The bisect log is: git bisect start # good: [b8095f24f24e50a7d4be33d8a79474aff3324295] Bump version to reflect v0.15.0-rc0 git bisect good b8095f24f24e50a7d4be33d8a79474aff3324295 # bad: [e072ea2fd8fdceef64159b9596d3c15ce01bea91] Bump version to 1.0-rc0 git bisect bad e072ea2fd8fdceef64159b9596d3c15ce01bea91 # bad: [7d4b4ba5c2bae99d44f265884b567ae63947bb4a] block: New change_media_cb() parameter load git bisect bad 7d4b4ba5c2bae99d44f265884b567ae63947bb4a # good: [baaa86d9f5d516d423d34af92e0c15b56e06ac4b] hw/9pfs: Update v9fs_create to use coroutines git bisect good baaa86d9f5d516d423d34af92e0c15b56e06ac4b # bad: [9aed1e036dc0de49d08d713f9e5c4655e94acb56] Rename qemu -> qemu-system-i386 git bisect bad 9aed1e036dc0de49d08d713f9e5c4655e94acb56 # good: [8ef9ea85a2cc1007eaefa53e6871f1f83bcef22d] Merge remote-tracking branch 'qemu-kvm/memory/batch' into staging git bisect good 8ef9ea85a2cc1007eaefa53e6871f1f83bcef22d # good: [9f4bd6baf64b8139cf2d7f8f53a98b27531da13c] Merge remote-tracking branch 'kwolf/for-anthony' into staging git bisect good 9f4bd6baf64b8139cf2d7f8f53a98b27531da13c # good: [09001ee7b27b9b5f049362efc427d03e2186a431] trace: [make] replace 'ifeq' with values in CONFIG_TRACE_* git bisect good 09001ee7b27b9b5f049362efc427d03e2186a431 # good: [d8e8ef4ee05bfee0df84e2665d9196c4a954c095] simpletrace: fix process() argument count git bisect good d8e8ef4ee05bfee0df84e2665d9196c4a954c095 # good: [a952c570c865d5eae6c148716f2cb585a0d3a2ee] Merge remote-tracking branch 'qemu-kvm-tmp/memory/core' into staging git bisect good a952c570c865d5eae6c148716f2cb585a0d3a2ee # good: [625f9e1f54cd78ee98ac22030da527c9a1cc9d2b] Merge remote-tracking branch 'stefanha/trivial-patches' into staging git bisect good 625f9e1f54cd78ee98ac22030da527c9a1cc9d2b # good: [d9cd446b4f6ff464f9520898116534de988d9bc1] trace: fix out-of-tree builds git bisect good d9cd446b4f6ff464f9520898116534de988d9bc1 # bad: [12d4536f7d911b6d87a766ad7300482ea663cea2] main: force enabling of I/O thread git bisect bad 12d4536f7d911b6d87a766ad7300482ea663cea2 -martin On 28.02.2012 18:05, Stefan Hajnoczi wrote: > On Tue, Feb 28, 2012 at 4:39 PM, Martin Mailand wrote: >> I could reproduce it and I bisected it down to this commit. >> >> 12d4536f7d911b6d87a766ad7300482ea663cea2 is the first bad commit >> commit 12d4536f7d911b6d87a766ad7300482ea663cea2 >> Author: Anthony Liguori >> Date: Mon Aug 22 08:24:58 2011 -0500 > This seems strange to me. > > What commit 12d4536f7 did was to switch to a threading model in > *qemu.git* that is similar to what *qemu-kvm.git* has been doing all > along. > > That means the qemu-kvm binaries already use the iothread model. The > only explanation I have is that your bisect went down a qemu.git path > and you therefore tripped over this - but in practice it should not > account for a difference between qemu-kvm 0.14.1 and 1.0. > > Can you please confirm that you are bisecting qemu-kvm.git and not qemu.git? > > Stefan