From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52398) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1drldY-0001Ln-ME for qemu-devel@nongnu.org; Tue, 12 Sep 2017 09:54:02 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1drldV-0006EK-Gf for qemu-devel@nongnu.org; Tue, 12 Sep 2017 09:54:00 -0400 Received: from mx1.redhat.com ([209.132.183.28]:32910) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1drldV-0006DV-7X for qemu-devel@nongnu.org; Tue, 12 Sep 2017 09:53:57 -0400 References: <59B7C252.1070004@huawei.com> <20170912113722.GH29136@localhost.localdomain> From: Eric Blake Message-ID: <96af9703-a35e-0baf-55b8-01f052a019b1@redhat.com> Date: Tue, 12 Sep 2017 08:53:47 -0500 MIME-Version: 1.0 In-Reply-To: <20170912113722.GH29136@localhost.localdomain> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="EWFO6huWgFixlNnkLHQD7BQ26s6jpxeq3" Subject: Re: [Qemu-devel] =?utf-8?q?question=EF=BC=9A_I_found_a_bug_which_wil?= =?utf-8?q?l_lead_to_qemu_crash?= List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Kevin Wolf , "WangJie (Captain)" Cc: famz@redhat.com, berto@igalia.com, qemu-devel@nongnu.org, stefanha@redhat.com, pbonzini@redhat.com This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --EWFO6huWgFixlNnkLHQD7BQ26s6jpxeq3 From: Eric Blake To: Kevin Wolf , "WangJie (Captain)" Cc: famz@redhat.com, berto@igalia.com, qemu-devel@nongnu.org, stefanha@redhat.com, pbonzini@redhat.com Message-ID: <96af9703-a35e-0baf-55b8-01f052a019b1@redhat.com> Subject: =?UTF-8?Q?Re:_[Qemu-devel]_question=ef=bc=9a_I_found_a_bug_which_wi?= =?UTF-8?Q?ll_lead_to_qemu_crash?= References: <59B7C252.1070004@huawei.com> <20170912113722.GH29136@localhost.localdomain> In-Reply-To: <20170912113722.GH29136@localhost.localdomain> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On 09/12/2017 06:37 AM, Kevin Wolf wrote: > Am 12.09.2017 um 13:17 hat WangJie (Captain) geschrieben: >> Hi, Kevin. >> >> I found a bug about qemu-kvm(version 2.7.0-rc0 adn 2.8.1). but qemu 2.= 6.0 and current master is OK. >> So I git-bisect the master branch=EF=BC=8Cand I found the patch you co= mmited (block: Decouple throttling from BlockDriverState) lead the bug in= to qemu. >> >> The patch which lead the bug into qemu: (https://github.com/qemu/qemu/= commit/7ca7f0f6db1fedd28d490795d778cf23979a2aa7#diff-ea36ba0f79150cc29973= 2696a069caba) >> >> Because the current master is OK. So I think you had fixed it , can yo= u tell me which patch fixed the bug? Thank you :> >=20 > I can't tell offhand which fix this was, but you can use 'git bisect' > not only to find which commit introduced the bug, but also to find the > fix. You just bisect between a broken commit and master, and then use > the reversed meaning of 'good' and 'bad' (i.e. 'good' means that the bu= g > is still there, 'bad' means it is already fixed). That can be mentally confusing; with new-enough git, you can also use: git bisect start --term-old=3Dbuggy --term-new=3Dfixed at which point, you can then say 'git bisect buggy' or 'git bisect fixed' according to whether the bug is still present on a given compilation, without having to remember which direction good/bad means. There's also 'git bisect terms' to remind you what you chose. --=20 Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3266 Virtualization: qemu.org | libvirt.org --EWFO6huWgFixlNnkLHQD7BQ26s6jpxeq3 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Comment: Public key at http://people.redhat.com/eblake/eblake.gpg Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQEzBAEBCAAdFiEEccLMIrHEYCkn0vOqp6FrSiUnQ2oFAlm35usACgkQp6FrSiUn Q2oy3AgAoJH7BXSxVkeXbKojHp7S2BCzt/+J1kNjt4r8v8mhM0xC7YdsZ797T6uW M64fQA4jzAuL73aKK9a5LhXDi3AuXLzSfZMcSLBtPIiHTMWlij6v9Y+ZIlSDP+/E fPKuwH10yyGgpoFHrW9Jdl5Ki4GVTgZXYlqUgNvdI9rmR2fYdw0CbpWyIHJaCUiR BcPojVfTzsmOhFDDCHvG1kq6S/ItVsYWamjGYlQgiCmBQi/TFzHpJ3WGdtXmPWKN +FE+JGqHkfBOwmK8hETvs5rzln1xmBGeVDY/o8ZmAhtCe6+Oof3VrXv1x9Gu2sFs lFN1nVhhH9mi8ABNB1d3i/wiw7S4SQ== =+c2Z -----END PGP SIGNATURE----- --EWFO6huWgFixlNnkLHQD7BQ26s6jpxeq3--