Commit-ID: 827db839cd051cfde5a618fb4427e86dc91bc9aa Gitweb: http://git.kernel.org/tip/827db839cd051cfde5a618fb4427e86dc91bc9aa Author: Thomas Gleixner <[email protected]> AuthorDate: Mon, 22 Feb 2016 22:19:20 +0000 Committer: Ingo Molnar <[email protected]> CommitDate: Mon, 29 Feb 2016 09:35:21 +0100
perf/x86/intel/cqm: Get rid of the silly for_each_cpu() lookups CQM is a strict per package facility. Use the proper cpumasks to lookup the readers. Signed-off-by: Thomas Gleixner <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Andi Kleen <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Harish Chegondi <[email protected]> Cc: Jacob Pan <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Kan Liang <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Stephane Eranian <[email protected]> Cc: Vince Weaver <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> --- arch/x86/events/intel/cqm.c | 32 +++++++++++--------------------- 1 file changed, 11 insertions(+), 21 deletions(-) diff --git a/arch/x86/events/intel/cqm.c b/arch/x86/events/intel/cqm.c index 1b064c4..93cb412 100644 --- a/arch/x86/events/intel/cqm.c +++ b/arch/x86/events/intel/cqm.c @@ -1244,15 +1244,12 @@ static struct pmu intel_cqm_pmu = { static inline void cqm_pick_event_reader(int cpu) { - int phys_id = topology_physical_package_id(cpu); - int i; + int reader; - for_each_cpu(i, &cqm_cpumask) { - if (phys_id == topology_physical_package_id(i)) - return; /* already got reader for this socket */ - } - - cpumask_set_cpu(cpu, &cqm_cpumask); + /* First online cpu in package becomes the reader */ + reader = cpumask_any_and(&cqm_cpumask, topology_core_cpumask(cpu)); + if (reader >= nr_cpu_ids) + cpumask_set_cpu(cpu, &cqm_cpumask); } static void intel_cqm_cpu_starting(unsigned int cpu) @@ -1270,24 +1267,17 @@ static void intel_cqm_cpu_starting(unsigned int cpu) static void intel_cqm_cpu_exit(unsigned int cpu) { - int phys_id = topology_physical_package_id(cpu); - int i; + int target; - /* - * Is @cpu a designated cqm reader? - */ + /* Is @cpu the current cqm reader for this package ? */ if (!cpumask_test_and_clear_cpu(cpu, &cqm_cpumask)) return; - for_each_online_cpu(i) { - if (i == cpu) - continue; + /* Find another online reader in this package */ + target = cpumask_any_but(topology_core_cpumask(cpu), cpu); - if (phys_id == topology_physical_package_id(i)) { - cpumask_set_cpu(i, &cqm_cpumask); - break; - } - } + if (target < nr_cpu_ids) + cpumask_set_cpu(target, &cqm_cpumask); } static int intel_cqm_cpu_notifier(struct notifier_block *nb,
