From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Cooper Subject: Re: kexec: Clear notes during setup Date: Fri, 4 May 2012 16:19:00 +0100 Message-ID: <4FA3F364.5050105@citrix.com> References: <4FA3C0A5.7030309@citrix.com> <4FA3ECF90200007800081A71@nat28.tlf.novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4FA3ECF90200007800081A71@nat28.tlf.novell.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: Jan Beulich Cc: "Keir (Xen.org)" , "xen-devel@lists.xen.org" List-Id: xen-devel@lists.xenproject.org On 04/05/12 13:51, Jan Beulich wrote: >>>> On 04.05.12 at 13:42, Andrew Cooper wrote: >> I know that xen-unstable is on a feature freeze, and this is not >> strictly a bugfix (yet; see below), but as it is safe and designed to >> help clarity in the case of a crash, so I request that it be considered >> for inclusion. >> >> I have constructed an artificial case where the information reported in >> 1 per-cpu crash note was stale by using low_crashinfo mode, crashing >> Xen, allowing it to reboot, offlining a CPU then re-crashing Xen. This >> leaves stale register state written into the offlined CPU crash >> information. In this case, the information was stale but correct, due >> to the predictable nature of the Xen crash path from the 'C' debug key, >> but there is no guarantee that in the case of a real crash, the same >> will still be true. > Apart from the missing blanks in the for() statement (which could as > well be a simple memset() afaict), > Acked-by: Jan Beulich > > I personally would think that this can go in as a bug fix. > > Jan How would you format the for loop differently? (Not that I mind - just so I know for next time) As for clear_page vs memset - clear_page is faster, and liable to be conditionally tuned more in the future. -- Andrew Cooper - Dom0 Kernel Engineer, Citrix XenServer T: +44 (0)1223 225 900, http://www.citrix.com