From mboxrd@z Thu Jan 1 00:00:00 1970 From: George Dunlap Subject: Re: [PATCH v4] xen/pygrub: grub2/grub.cfg from RHEL 7 has new commands in menuentry Date: Wed, 5 Feb 2014 11:49:15 +0000 Message-ID: <52F2253B.9000000@eu.citrix.com> References: <20140204181023.GA5293@citrix.com> <1391592179.6497.73.camel@kazak.uk.xensource.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1391592179.6497.73.camel@kazak.uk.xensource.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Ian Campbell , Joby Poriyath Cc: Andrew Cooper , xen-devel@lists.xen.org List-Id: xen-devel@lists.xenproject.org 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'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. >> >> 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). 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. -George