From mboxrd@z Thu Jan 1 00:00:00 1970 From: Konrad Rzeszutek Wilk Subject: Re: [PATCH RFC v2 2/2] linux/vnuma: Enables NUMA for domu PV guest Date: Fri, 27 Sep 2013 13:03:58 -0400 Message-ID: <20130927170358.GA11397@phenom.dumpdata.com> References: <1379406841-7441-1-git-send-email-ufimtseva@gmail.com> <1379406841-7441-3-git-send-email-ufimtseva@gmail.com> <1379517289.18543.154.camel@Abyss> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <1379517289.18543.154.camel@Abyss> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Dario Faggioli Cc: Elena Ufimtseva , lccycc123@gmail.com, george.dunlap@eu.citrix.com, xen-devel@lists.xen.org, david.vrabel@citrix.com, msw@amazon.com, boris.ostrovsky@oracle.com List-Id: xen-devel@lists.xenproject.org On Wed, Sep 18, 2013 at 05:14:49PM +0200, Dario Faggioli wrote: > On mar, 2013-09-17 at 04:34 -0400, Elena Ufimtseva wrote: > > diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c > > index 8f3eea6..2f2d28e 100644 > > --- a/arch/x86/xen/setup.c > > +++ b/arch/x86/xen/setup.c > > > > #include > > #include > > @@ -583,6 +584,9 @@ void __init xen_arch_setup(void) > > WARN_ON(xen_set_default_idle()); > > fiddle_vdso(); > > #ifdef CONFIG_NUMA > > - numa_off = 1; > > + if (!xen_initial_domain() && xen_vnuma_support()) > > + numa_off = 0; > > + else > > + numa_off = 1; > > #endif > > } > I can't be positive about this, but I think that, if we go for David's > suggestions of: > - testing for the hypercall being actually supported, > - calling dummy_numa_init() directly from within xen_numa_init (in > case something go wrong), instead of going through all the > alternatives from x86_numa_init() > > then we can even get rid of this numa_off=0|1 all together (which is > also something David was already suggesting, AFAICR). You could do: if (xen_initial_domain()) && !xen_vnuma_support()) numa_off = 1; And just do that. The PV guest (the plain one) can then go on and just do the dummy one. > > It would be nice to know what the issue was at the time they had to > introduce this, and whether we can get to do some testing on any of the > boxes where it was exploding. konrad@phenom:~/linux$ git annotate arch/x86/xen/setup.c|grep numa_off 8d54db795 (Konrad Rzeszutek Wilk 2012-08-17 10:22:37 -0400 601) numa_off = 1; konrad@phenom:~/linux$ git show 8d54db795 commit 8d54db795dfb1049d45dc34f0dddbc5347ec5642 Author: Konrad Rzeszutek Wilk Date: Fri Aug 17 10:22:37 2012 -0400 xen/boot: Disable NUMA for PV guests. .... this scanning is still enabled (K8 and Fam10h, not Bulldozer class) .. Pid: 0, comm: swapper Not tainted 3.3.6 #1 AMD Dinar/Dinar > > I'll investigate more, in the meanwhile, does anyone had any clue? > > Dario > > -- > <> (Raistlin Majere) > ----------------------------------------------------------------- > Dario Faggioli, Ph.D, http://about.me/dario.faggioli > Senior Software Engineer, Citrix Systems R&D Ltd., Cambridge (UK) > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xen.org > http://lists.xen.org/xen-devel