Messages in this thread | | | Date | Mon, 25 Feb 2008 21:27:42 -0800 | From | "Yinghai Lu" <> | Subject | Re: [PATCH] x86_64: make amd quad core 8 socket system not be clustered_box v2 |
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On Mon, Feb 25, 2008 at 8:05 PM, Ravikiran Thirumalai <kiran@scalemp.com> wrote: > On Tue, Feb 26, 2008 at 04:46:25AM +0100, Andi Kleen wrote: > >> I don't quite understand the purpose of the patch to begin with. Looking at > >> the current x86 git tree, apic_is_clustered_box is used only to determine if > >> tsc is synchronized on the platform. The AMD docs imply that TSC's are not > >> guaranteed to be synced across cores between nodes -- Opteron BKDG for > >> family 10h, Section 2.9.4: > > > >After long discussions with AMD they determined the CPUID flag > >for sync RDTSC will imply synchronization between nodes. > > Ah! > > > > > >If you can't support that in your hardware you're supposed > >to clear it. > > Hmm! How would a hardware vendor do that? That doesn't seem to be clear in > the BKDG. (Well, this is the problem with undocumented features :() > any good sign for APIC_clustered box? there is apicid between cpus even all cpu are quadcore and fully populated?
YH
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