Messages in this thread | | | Date | Sat, 3 Dec 2005 00:02:06 +0100 | From | Andi Kleen <> | Subject | Re: [discuss] Re: [patch 1/3] x86_64: Node local PDA -- early cpu_to_node |
| |
On Fri, Dec 02, 2005 at 02:51:56PM -0800, Ravikiran G Thirumalai wrote: > On Fri, Dec 02, 2005 at 12:43:49PM +0100, Andi Kleen wrote: > > > +#ifdef CONFIG_ACPI_NUMA > > > + /* > > > + * Setup cpu_to_node using the SRAT lapcis & ACPI MADT table > > > + * info. > > > + */ > > > + for (i = 0; i < NR_CPUS; i++) > > > + cpu_to_node[i] = apicid_to_node[x86_cpu_to_apicid[i]]; > > > +#endif > > > > This should be in a separate function in srat.c. > > OK, > > > > > And are you sure it will work with k8topology.c. Doesn't look like > > that to me. > > I don't have a K8 box yet :(, so I cannot confirm either ways. > But I thought newer opterons need to use ACPI_NUMA instead...
k8topology still needs to work - e.g. for LinuxBios and users which use acpi=off and as a fallback for broken SRAT tables. You can't break it right now.
> > <Kconfig quote> > config K8_NUMA > bool "Old style AMD Opteron NUMA detection" > depends on NUMA > default y > help > Enable K8 NUMA node topology detection. You should say Y here if > you have a multi processor AMD K8 system. This uses an old > method to read the NUMA configurtion directly from the builtin > Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA > instead, which also takes priority if both are compiled in. > </quote> > > Even if K8 detection is used, cpu_pda will have memory allocated from node0 > which is not different from the current state. So this patch helps Opterons > and EM64t boxes which use ACPI_NUMA, right? Also the newer opteron boxes > and em64t NUMA boxes can now get node local memory for static per-cpu areas.
Hmm good point. However i would prefer if there was no performance regression between the two options. However i guess it can be kept like this now. Just make sure to comment it well.
-Andi
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |