From xen-devel-bounces@lists.xen.org Wed Feb 05 12:12:40 2014 Received: (at maildrop) by bugs.xenproject.org; 5 Feb 2014 12:12:40 +0000 Received: from lists.xen.org ([50.57.142.19]) by bugs.xenproject.org with esmtp (Exim 4.80) (envelope-from ) id 1WB1LM-0007LR-AA for xen-devel-maildrop-Eithu9ie@bugs.xenproject.org; Wed, 05 Feb 2014 12:12:40 +0000 Received: from localhost ([127.0.0.1] helo=lists.xen.org) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1WB1GB-0003u0-Rz; Wed, 05 Feb 2014 12:07:19 +0000 Received: from mail6.bemta14.messagelabs.com ([193.109.254.103]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1WB1GA-0003tv-Sq for xen-devel@lists.xen.org; Wed, 05 Feb 2014 12:07:19 +0000 Received: from [193.109.254.147:59001] by server-5.bemta-14.messagelabs.com id FC/51-16688-67922F25; Wed, 05 Feb 2014 12:07:18 +0000 X-Env-Sender: Ian.Campbell@citrix.com X-Msg-Ref: server-6.tower-27.messagelabs.com!1391602036!2172526!1 X-Originating-IP: [66.165.176.89] X-SpamReason: No, hits=0.0 required=7.0 tests=sa_preprocessor: VHJ1c3RlZCBJUDogNjYuMTY1LjE3Ni44OSA9PiAyMDMwMDc=\n X-StarScan-Received: X-StarScan-Version: 6.9.16; banners=-,-,- X-VirusChecked: Checked Received: (qmail 9901 invoked from network); 5 Feb 2014 12:07:17 -0000 Received: from smtp.citrix.com (HELO SMTP.CITRIX.COM) (66.165.176.89) by server-6.tower-27.messagelabs.com with RC4-SHA encrypted SMTP; 5 Feb 2014 12:07:17 -0000 X-IronPort-AV: E=Sophos;i="4.95,786,1384300800"; d="scan'208";a="100058930" Received: from accessns.citrite.net (HELO FTLPEX01CL01.citrite.net) ([10.9.154.239]) by FTLPIPO01.CITRIX.COM with ESMTP; 05 Feb 2014 12:07:16 +0000 Received: from [10.80.2.80] (10.80.2.80) by FTLPEX01CL01.citrite.net (10.13.107.78) with Microsoft SMTP Server id 14.2.342.4; Wed, 5 Feb 2014 07:07:15 -0500 Message-ID: <1391602034.6497.128.camel@kazak.uk.xensource.com> From: Ian Campbell To: George Dunlap Date: Wed, 5 Feb 2014 12:07:14 +0000 In-Reply-To: <52F2253B.9000000@eu.citrix.com> References: <20140204181023.GA5293@citrix.com> <1391592179.6497.73.camel@kazak.uk.xensource.com> <52F2253B.9000000@eu.citrix.com> Organization: Citrix Systems, Inc. X-Mailer: Evolution 3.4.4-3 MIME-Version: 1.0 X-Originating-IP: [10.80.2.80] X-DLP: MIA1 Cc: Andrew Cooper , Joby Poriyath , xen-devel@lists.xen.org Subject: Re: [Xen-devel] [PATCH v4] xen/pygrub: grub2/grub.cfg from RHEL 7 has new commands in menuentry X-BeenThere: xen-devel@lists.xen.org X-Mailman-Version: 2.1.13 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org On Wed, 2014-02-05 at 11:49 +0000, George Dunlap wrote: > On 02/05/2014 09:22 AM, Ian Campbell wrote: > > On Tue, 2014-02-04 at 18:10 +0000, Joby Poriyath wrote: > >> menuentry in grub2/grub.cfg uses linux16 and initrd16 commands > >> instead of linux and initrd. Due to this RHEL 7 (beta) guest failed to > >> boot after the installation. > >> > >> In addition to this, RHEL 7 menu entries have two different single-quote > >> delimited strings on the same line, and the greedy grouping for menuentry > >> parsing gets both strings, and the options inbetween. > > So you're saying that adding the '?' just happens to change the match > because of a quirk in the algorithms in the python library? That seems > more like a hack than a proper fix; there may be other versions of > python (future versions, for instance) where the new regexp will have > the same effect as the old one, and we'll have another regression. > > Even if the behavior described is part of the defined interface, I believe it is. Joby posted a link earlier. It also seems to be part of the Perl re syntax -- and lots of things use Perl's regex syntax so I think it is pretty "standard" (although I was not previously aware of it either). Wikipedia's regex page talks about it too. > I'd be > wary of using this because future developers may not realize what it's > for, or how to modify it properly to retain the properties it has now. Hypothetical developer ignorance might call for a comment, but I think avoiding language features which provide the semantics we need just because they are a bit obscure would be a mistake. > >> Signed-off-by: Joby Poriyath > >> Reviewed-by: Andrew Cooper > >> Cc: george.dunlap@citrix.com > > Acked-by: Ian Campbell > > > > IMHO this can go into 4.4, unless George objects today I shall commit. > > I'm a bit on the fence about this one. If this had been sent a month > ago, it would be a no-brainer. It certainly looks like it should work > just fine. On the other hand, pygrub is an important bit of > functionality, and I'm not sure how much testing it gets. But of course > the XenServer XenRT tests probably exercise it fairly well (or else they > wouldn't be submitting this patch). FWIW I intended to run it over the (admittedly small) set of test cases in the tree as part of the commit process. I believe Joby has already done so anyway. > The Register seems to think that RHEL will be released "in the first > half of 2014", which would certainly be before 4.5. But we should have > another point release before then, with enough time to do better testing > and (possibly) come up with a better solution to the regexp problem > above (assuming my interpretation is correct). > > I'm wondering though whether it would make more sense to save this for > 4.4.1. _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel