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| author | Yan, Zheng <zheng.z.yan@intel.com> | 2013-04-16 19:51:05 +0800 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2013-04-21 10:59:01 +0200 |
| commit | 22cc4ccf63e10e361531bf61e6e6c96c53a2f665 (patch) | |
| tree | 0deeb72d431b7916cb0a42ca1983ec2a250fa3d2 /arch/x86 | |
| parent | 73e21ce28d8d2b75140b742b01373c3a085ecc52 (diff) | |
| download | op-kernel-dev-22cc4ccf63e10e361531bf61e6e6c96c53a2f665.zip op-kernel-dev-22cc4ccf63e10e361531bf61e6e6c96c53a2f665.tar.gz | |
perf/x86: Avoid kfree() in CPU_{STARTING,DYING}
On -rt kfree() can schedule, but CPU_{STARTING,DYING} should be
atomic. So use a list to defer kfree until CPU_{ONLINE,DEAD}.
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: peterz@infradead.org
Cc: eranian@google.com
Cc: ak@linux.intel.com
Link: http://lkml.kernel.org/r/1366113067-3262-2-git-send-email-zheng.z.yan@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/kernel/cpu/perf_event_intel_uncore.c | 28 |
1 files changed, 25 insertions, 3 deletions
diff --git a/arch/x86/kernel/cpu/perf_event_intel_uncore.c b/arch/x86/kernel/cpu/perf_event_intel_uncore.c index 75da9e1..50d4a1c 100644 --- a/arch/x86/kernel/cpu/perf_event_intel_uncore.c +++ b/arch/x86/kernel/cpu/perf_event_intel_uncore.c @@ -2622,6 +2622,21 @@ static void __init uncore_pci_exit(void) } } +/* CPU hot plug/unplug are serialized by cpu_add_remove_lock mutex */ +static LIST_HEAD(boxes_to_free); + +static void __cpuinit uncore_kfree_boxes(void) +{ + struct intel_uncore_box *box; + + while (!list_empty(&boxes_to_free)) { + box = list_entry(boxes_to_free.next, + struct intel_uncore_box, list); + list_del(&box->list); + kfree(box); + } +} + static void __cpuinit uncore_cpu_dying(int cpu) { struct intel_uncore_type *type; @@ -2636,7 +2651,7 @@ static void __cpuinit uncore_cpu_dying(int cpu) box = *per_cpu_ptr(pmu->box, cpu); *per_cpu_ptr(pmu->box, cpu) = NULL; if (box && atomic_dec_and_test(&box->refcnt)) - kfree(box); + list_add(&box->list, &boxes_to_free); } } } @@ -2666,8 +2681,11 @@ static int __cpuinit uncore_cpu_starting(int cpu) if (exist && exist->phys_id == phys_id) { atomic_inc(&exist->refcnt); *per_cpu_ptr(pmu->box, cpu) = exist; - kfree(box); - box = NULL; + if (box) { + list_add(&box->list, + &boxes_to_free); + box = NULL; + } break; } } @@ -2806,6 +2824,10 @@ static int case CPU_DYING: uncore_cpu_dying(cpu); break; + case CPU_ONLINE: + case CPU_DEAD: + uncore_kfree_boxes(); + break; default: break; } |
