Messages in this thread Patch in this message | | | Subject | Re: [PATCH 5/7] perf: Optimise topology iteration | From | Lin Ming <> | Date | Tue, 04 Jan 2011 14:18:37 +0800 |
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On Mon, 2011-01-03 at 19:02 +0800, Peter Zijlstra wrote: > On Mon, 2010-12-27 at 23:38 +0800, Lin Ming wrote: > > Currently we iterate the full machine looking for a matching core_id/nb > > for the percore and the amd northbridge stuff , using a smaller topology > > mask makes sense. > > Does topology_thread_cpumask() include offline cpus? I tried looking at > it, but I cannot find any code clearing bits in that mask on offline.
No, it does not include offline cpus. For x86 code, remove_siblinginfo() clears the bits.
take_cpu_down -> __cpu_disable -> native_cpu_disable -> cpu_disable_common -> remove_siblinginfo
static void remove_siblinginfo(int cpu) { int sibling; struct cpuinfo_x86 *c = &cpu_data(cpu);
for_each_cpu(sibling, cpu_core_mask(cpu)) { cpumask_clear_cpu(cpu, cpu_core_mask(sibling)); /*/ * last thread sibling in this cpu core going down */ if (cpumask_weight(cpu_sibling_mask(cpu)) == 1) cpu_data(sibling).booted_cores--; }
for_each_cpu(sibling, cpu_sibling_mask(cpu)) cpumask_clear_cpu(cpu, cpu_sibling_mask(sibling)); cpumask_clear(cpu_sibling_mask(cpu)); cpumask_clear(cpu_core_mask(cpu)); c->phys_proc_id = 0; c->cpu_core_id = 0; cpumask_clear_cpu(cpu, cpu_sibling_setup_mask); }
Lin Ming
> > > Signed-off-by: Lin Ming <ming.m.lin@intel.com> > > --- > > arch/x86/kernel/cpu/perf_event_amd.c | 2 +- > > arch/x86/kernel/cpu/perf_event_intel.c | 2 +- > > 2 files changed, 2 insertions(+), 2 deletions(-) > > > > diff --git a/arch/x86/kernel/cpu/perf_event_amd.c b/arch/x86/kernel/cpu/perf_event_amd.c > > index 67e2202..5a3b7b8 100644 > > --- a/arch/x86/kernel/cpu/perf_event_amd.c > > +++ b/arch/x86/kernel/cpu/perf_event_amd.c > > @@ -323,7 +323,7 @@ static void amd_pmu_cpu_starting(int cpu) > > nb_id = amd_get_nb_id(cpu); > > WARN_ON_ONCE(nb_id == BAD_APICID); > > > > - for_each_online_cpu(i) { > > + for_each_cpu(i, topology_core_cpumask(cpu)) { > > nb = per_cpu(cpu_hw_events, i).amd_nb; > > if (WARN_ON_ONCE(!nb)) > > continue; > > diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c > > index 354d1de..ad70c2c 100644 > > --- a/arch/x86/kernel/cpu/perf_event_intel.c > > +++ b/arch/x86/kernel/cpu/perf_event_intel.c > > @@ -1111,7 +1111,7 @@ static void intel_pmu_cpu_starting(int cpu) > > if (!ht_enabled(cpu)) > > return; > > > > - for_each_online_cpu(i) { > > + for_each_cpu(i, topology_thread_cpumask(cpu)) { > > struct intel_percore *pc = per_cpu(cpu_hw_events, i).per_core; > > > > if (pc && pc->core_id == core_id) { > >
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