From 1aa6cfd33df492939b0be15ebdbcff1f8ae5ddb6 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Tue, 31 Jan 2017 23:58:39 +0100 Subject: [PATCH] perf/x86/intel/uncore: Clean up hotplug conversion fallout The recent conversion to the hotplug state machine kept two mechanisms from the original code: 1) The first_init logic which adds the number of online CPUs in a package to the refcount. That's wrong because the callbacks are executed for all online CPUs. Remove it so the refcounting is correct. 2) The on_each_cpu() call to undo box->init() in the error handling path. That's bogus because when the prepare callback fails no box has been initialized yet. Remove it. Signed-off-by: Thomas Gleixner Cc: Alexander Shishkin Cc: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Sebastian Siewior Cc: Stephane Eranian Cc: Vince Weaver Cc: Yasuaki Ishimatsu Fixes: 1a246b9f58c6 ("perf/x86/intel/uncore: Convert to hotplug state machine") Link: http://lkml.kernel.org/r/20170131230141.298032324@linutronix.de Signed-off-by: Ingo Molnar --- arch/x86/events/intel/uncore.c | 44 ++++------------------------------ 1 file changed, 4 insertions(+), 40 deletions(-) diff --git a/arch/x86/events/intel/uncore.c b/arch/x86/events/intel/uncore.c index 8c4ccdc3a3f3..56c5235dcc29 100644 --- a/arch/x86/events/intel/uncore.c +++ b/arch/x86/events/intel/uncore.c @@ -764,30 +764,6 @@ static void uncore_pmu_unregister(struct intel_uncore_pmu *pmu) pmu->registered = false; } -static void __uncore_exit_boxes(struct intel_uncore_type *type, int cpu) -{ - struct intel_uncore_pmu *pmu = type->pmus; - struct intel_uncore_box *box; - int i, pkg; - - if (pmu) { - pkg = topology_physical_package_id(cpu); - for (i = 0; i < type->num_boxes; i++, pmu++) { - box = pmu->boxes[pkg]; - if (box) - uncore_box_exit(box); - } - } -} - -static void uncore_exit_boxes(void *dummy) -{ - struct intel_uncore_type **types; - - for (types = uncore_msr_uncores; *types; types++) - __uncore_exit_boxes(*types++, smp_processor_id()); -} - static void uncore_free_boxes(struct intel_uncore_pmu *pmu) { int pkg; @@ -1078,22 +1054,12 @@ static int uncore_cpu_dying(unsigned int cpu) return 0; } -static int first_init; - static int uncore_cpu_starting(unsigned int cpu) { struct intel_uncore_type *type, **types = uncore_msr_uncores; struct intel_uncore_pmu *pmu; struct intel_uncore_box *box; - int i, pkg, ncpus = 1; - - if (first_init) { - /* - * On init we get the number of online cpus in the package - * and set refcount for all of them. - */ - ncpus = cpumask_weight(topology_core_cpumask(cpu)); - } + int i, pkg; pkg = topology_logical_package_id(cpu); for (; *types; types++) { @@ -1104,7 +1070,7 @@ static int uncore_cpu_starting(unsigned int cpu) if (!box) continue; /* The first cpu on a package activates the box */ - if (atomic_add_return(ncpus, &box->refcnt) == ncpus) + if (atomic_inc_return(&box->refcnt) == 1) uncore_box_init(box); } } @@ -1408,19 +1374,17 @@ static int __init intel_uncore_init(void) "perf/x86/intel/uncore:prepare", uncore_cpu_prepare, NULL); } - first_init = 1; + cpuhp_setup_state(CPUHP_AP_PERF_X86_UNCORE_STARTING, "perf/x86/uncore:starting", uncore_cpu_starting, uncore_cpu_dying); - first_init = 0; + cpuhp_setup_state(CPUHP_AP_PERF_X86_UNCORE_ONLINE, "perf/x86/uncore:online", uncore_event_cpu_online, uncore_event_cpu_offline); return 0; err: - /* Undo box->init_box() */ - on_each_cpu_mask(&uncore_cpu_mask, uncore_exit_boxes, NULL, 1); uncore_types_exit(uncore_msr_uncores); uncore_pci_exit(); return ret; -- 2.30.2