From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Jan Beulich" Subject: Re: [PATCH v2 16/30] x86/cpu: Move set_cpumask() calls into c_early_init() Date: Wed, 17 Feb 2016 03:58:37 -0700 Message-ID: <56C4606D02000078000D30F4@prv-mh.provo.novell.com> References: <1454679743-18133-1-git-send-email-andrew.cooper3@citrix.com> <1454679743-18133-17-git-send-email-andrew.cooper3@citrix.com> <56C33BFA02000078000D2AAC@prv-mh.provo.novell.com> <56C44F44.9070703@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <56C44F44.9070703@citrix.com> Content-Disposition: inline List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Andrew Cooper Cc: Xen-devel List-Id: xen-devel@lists.xenproject.org >>> On 17.02.16 at 11:45, wrote: > On 16/02/16 14:10, Jan Beulich wrote: >>>>> On 05.02.16 at 14:42, wrote: >>> Before c/s 44e24f8567 "x86: don't call generic_identify() redundantly", the >>> commandline-provided masks would take effect in Xen's view of the features. >>> >>> As the masks got applied after the query for features, the redundant call to >>> generic_identify() would clobber the pre-masking feature information with the >>> post-masking information. >>> >>> Move the set_cpumask() calls into c_early_init() so their effects take place >>> before the main query for features in generic_identify(). >>> >>> The cpuid_mask_* command line parameters now limit the entire system, a >>> feature XenServer was relying on for testing purposes. >> And I continue to view this as a step backwards, and hence can't >> really approve of this change. > > It is not a step backwards. Being able to disable features in Xen is > critical for testing. You accidentally broke that with a patch which > was supposed to be no functional change. Views differ: I would say I unknowingly fixed this with that patch (as to me it was always clear that this masking should not apply to Xen itself). If that behavior is critical for testing, add a command line option to enable it. > This series means that these command line options are not required for > levelling. By the end of the series, agreed. Jan