Messages in this thread | | | Date | Wed, 26 Mar 2014 23:01:07 +0100 | Subject | Re: [PATCH] x86: Fix boot on uniprocessor systems | From | Stephane Eranian <> |
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On Wed, Mar 26, 2014 at 9:31 PM, Andrew Morton <akpm@linux-foundation.org> wrote: > On Tue, 25 Mar 2014 01:59:10 +0300 Artem Fetishev <artem_fetishev@epam.com> wrote: > >> On x86 uniprocessor systems topology_physical_package_id() returns -1 which >> causes rapl_cpu_prepare() to leave rapl_pmu variable uninitialized which leads >> to GPF in rapl_pmu_init(). See arch/x86/kernel/cpu/perf_event_intel_rapl.c. >> >> It turns out that physical_package_id and core_id can actually be retreived for >> uniprocessor systems too. Enabling them also fixes rapl_pmu code. >> >> Signed-off-by: Artem Fetishev <artem_fetishev@epam.com> >> --- >> diff --git a/arch/x86/include/asm/topology.h b/arch/x86/include/asm/topology.h >> index d35f24e..1306d11 100644 >> --- a/arch/x86/include/asm/topology.h >> +++ b/arch/x86/include/asm/topology.h >> @@ -119,9 +119,10 @@ static inline void setup_node_to_cpumask_map(void) { } >> >> extern const struct cpumask *cpu_coregroup_mask(int cpu); >> >> -#ifdef ENABLE_TOPO_DEFINES >> #define topology_physical_package_id(cpu) (cpu_data(cpu).phys_proc_id) >> #define topology_core_id(cpu) (cpu_data(cpu).cpu_core_id) >> + >> +#ifdef ENABLE_TOPO_DEFINES >> #define topology_core_cpumask(cpu) (per_cpu(cpu_core_map, cpu)) >> #define topology_thread_cpumask(cpu) (per_cpu(cpu_sibling_map, cpu)) >> #endif > > The patch applies to 3.13 and perhaps earlier kernels. Is it needed in > those kernel versions?
Before 3.13 there was no RAPL support. But it seems the patch is still useful regardless
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