From 6909262429b70a162e9e7053672cfd8024c9275d Mon Sep 17 00:00:00 2001 From: Lin Ming Date: Thu, 3 Mar 2011 10:34:50 +0800 Subject: [PATCH] perf: Avoid the percore allocations if the CPU is not HT capable Signed-off-by: Lin Ming Signed-off-by: Peter Zijlstra LKML-Reference: <1299119690-13991-5-git-send-email-ming.m.lin@intel.com> Signed-off-by: Ingo Molnar --- arch/x86/include/asm/smp.h | 10 ++++++++++ arch/x86/kernel/cpu/perf_event.c | 1 + arch/x86/kernel/cpu/perf_event_intel.c | 18 ++++++++++++------ 3 files changed, 23 insertions(+), 6 deletions(-) diff --git a/arch/x86/include/asm/smp.h b/arch/x86/include/asm/smp.h index 1f46951..c1bbfa8 100644 --- a/arch/x86/include/asm/smp.h +++ b/arch/x86/include/asm/smp.h @@ -17,10 +17,20 @@ #endif #include #include +#include extern int smp_num_siblings; extern unsigned int num_processors; +static inline bool cpu_has_ht_siblings(void) +{ + bool has_siblings = false; +#ifdef CONFIG_SMP + has_siblings = cpu_has_ht && smp_num_siblings > 1; +#endif + return has_siblings; +} + DECLARE_PER_CPU(cpumask_var_t, cpu_sibling_map); DECLARE_PER_CPU(cpumask_var_t, cpu_core_map); DECLARE_PER_CPU(u16, cpu_llc_id); diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c index 4d6ce5d..2660418 100644 --- a/arch/x86/kernel/cpu/perf_event.c +++ b/arch/x86/kernel/cpu/perf_event.c @@ -30,6 +30,7 @@ #include #include #include +#include #if 0 #undef wrmsrl diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c index 6e9b676..8fc2b2c 100644 --- a/arch/x86/kernel/cpu/perf_event_intel.c +++ b/arch/x86/kernel/cpu/perf_event_intel.c @@ -1205,6 +1205,9 @@ static int intel_pmu_cpu_prepare(int cpu) { struct cpu_hw_events *cpuc = &per_cpu(cpu_hw_events, cpu); + if (!cpu_has_ht_siblings()) + return NOTIFY_OK; + cpuc->per_core = kzalloc_node(sizeof(struct intel_percore), GFP_KERNEL, cpu_to_node(cpu)); if (!cpuc->per_core) @@ -1221,6 +1224,15 @@ static void intel_pmu_cpu_starting(int cpu) int core_id = topology_core_id(cpu); int i; + init_debug_store_on_cpu(cpu); + /* + * Deal with CPUs that don't clear their LBRs on power-up. + */ + intel_pmu_lbr_reset(); + + if (!cpu_has_ht_siblings()) + return; + for_each_cpu(i, topology_thread_cpumask(cpu)) { struct intel_percore *pc = per_cpu(cpu_hw_events, i).per_core; @@ -1233,12 +1245,6 @@ static void intel_pmu_cpu_starting(int cpu) cpuc->per_core->core_id = core_id; cpuc->per_core->refcnt++; - - init_debug_store_on_cpu(cpu); - /* - * Deal with CPUs that don't clear their LBRs on power-up. - */ - intel_pmu_lbr_reset(); } static void intel_pmu_cpu_dying(int cpu) -- 2.7.4