Hi, Looking at a bug where dom0 is crashing coming up with more than 32 vcpus, the problem happens trying to initialize 32nd vcpu. I see the shared info is limited to 32vcpus, implying we''d have a hard limit of 32 vcpus in dom0, correct? For now, I can just fix our dom0 to not go above 32, and look at ways of fixing it if there''s a strong case for more than 32 vcpus in dom0. thanks, Mukesh _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
>>> Mukesh Rathor 04/27/10 4:20 AM >>> >Looking at a bug where dom0 is crashing coming up with more than 32 >vcpus, the problem happens trying to initialize 32nd vcpu. I see >the shared info is limited to 32vcpus, implying we''d have a hard limit >of 32 vcpus in dom0, correct?That''s the legacy limit, yes. Any attempt to go beyond 32 CPUs requires the kernel to use the per-vCPU-info-placement hypercall prior to bringing up those vCPU-s. Jan _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
On Mon, Apr 26, 2010 at 07:17:33PM -0700, Mukesh Rathor wrote:> Hi, > > Looking at a bug where dom0 is crashing coming up with more than 32 > vcpus, the problem happens trying to initialize 32nd vcpu. I see > the shared info is limited to 32vcpus, implying we''d have a hard limit > of 32 vcpus in dom0, correct? >''shared info'' in Xen hypervisor or in the dom0 kernel?> For now, I can just fix our dom0 to not go above 32, and look at ways > of fixing it if there''s a strong case for more than 32 vcpus in dom0. >Which dom0 kernel did you test with? -- Pasi _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
On 04/27/2010 01:59 AM, Pasi Kärkkäinen wrote:>> Looking at a bug where dom0 is crashing coming up with more than 32 >> vcpus, the problem happens trying to initialize 32nd vcpu. I see >> the shared info is limited to 32vcpus, implying we''d have a hard limit >> of 32 vcpus in dom0, correct? >> >> > ''shared info'' in Xen hypervisor or in the dom0 kernel? >Both ;) It''s shared. J _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
On Tue, Apr 27, 2010 at 11:38:30AM -0700, Jeremy Fitzhardinge wrote:> On 04/27/2010 01:59 AM, Pasi Kärkkäinen wrote: > >> Looking at a bug where dom0 is crashing coming up with more than 32 > >> vcpus, the problem happens trying to initialize 32nd vcpu. I see > >> the shared info is limited to 32vcpus, implying we''d have a hard limit > >> of 32 vcpus in dom0, correct? > >> > >> > > ''shared info'' in Xen hypervisor or in the dom0 kernel? > > > > Both ;) It''s shared. >Oh, shared like *that* :) Thanks. -- Pasi _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
On Tue, 27 Apr 2010 09:23:19 +0100 "Jan Beulich" <jbeulich@novell.com> wrote:> >>> Mukesh Rathor 04/27/10 4:20 AM >>> > >Looking at a bug where dom0 is crashing coming up with more than 32 > >vcpus, the problem happens trying to initialize 32nd vcpu. I see > >the shared info is limited to 32vcpus, implying we''d have a hard > >limit of 32 vcpus in dom0, correct? > > That''s the legacy limit, yes. Any attempt to go beyond 32 CPUs > requires the kernel to use the per-vCPU-info-placement hypercall > prior to bringing up those vCPU-s. > > JanHi Jan, Yes, I found your patch searching xen-devel implementing VCPUOP_register_vcpu_info after I posted my msg. However, I don''t find any kernel using this other than pv-ops kernel. So I assume this is work in progress. If you already have a patch for 2.6.18-xxx, please let me know, if not, I''ll work on it. thanks, Mukesh _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
>>> Mukesh Rathor 04/28/10 4:35 AM >>> >Yes, I found your patch searching xen-devel implementing >VCPUOP_register_vcpu_info after I posted my msg. However, I don''t find >any kernel using this other than pv-ops kernel. So I assume this is >work in progress. If you already have a patch for 2.6.18-xxx, please let >me know, if not, I''ll work on it.While we use it in our newer forward ported trees (2.6.32 onwards), the patch isn''t easily backported to 2.6.18, and hence I refrained from submitting anything to xen-devel. Jan _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
On 04/27/2010 07:34 PM, Mukesh Rathor wrote:> Yes, I found your patch searching xen-devel implementing > VCPUOP_register_vcpu_info after I posted my msg. However, I don''t find > any kernel using this other than pv-ops kernel. So I assume this is > work in progress. If you already have a patch for 2.6.18-xxx, please let > me know, if not, I''ll work on it. >What''s the use-case for a dom0 with a large number of vcpus? J _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel