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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 <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: 1a246b9f58 ("perf/x86/intel/uncore: Convert to hotplug state machine")
Link: http://lkml.kernel.org/r/20170131230141.298032324@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Thomas Gleixner 2017-01-31 23:58:39 +01:00 committed by Ingo Molnar
parent dd86e373e0
commit 1aa6cfd33d
1 changed files with 4 additions and 40 deletions
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44
arch/x86/events/intel/uncore.c
View File

@ -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;