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Commit 1aa6cfd3 authored by Thomas Gleixner's avatar Thomas Gleixner Committed by Ingo Molnar
Browse files

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: default avatarThomas Gleixner <tglx@linutronix.de>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Stephane Eranian <eranian@google.com>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: Yasuaki Ishimatsu <yasu.isimatu@gmail.com>
Fixes: 1a246b9f ("perf/x86/intel/uncore: Convert to hotplug state machine")
Link: http://lkml.kernel.org/r/20170131230141.298032324@linutronix.de


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent dd86e373

arch/x86/events/intel/uncore.c

+4 −40
Original line number Diff line number Diff line
@@ -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;