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-rw-r--r--arch/powerpc/perf/imc-pmu.c39
1 files changed, 34 insertions, 5 deletions
diff --git a/arch/powerpc/perf/imc-pmu.c b/arch/powerpc/perf/imc-pmu.c
index 9ccac86f3463..88126245881b 100644
--- a/arch/powerpc/perf/imc-pmu.c
+++ b/arch/powerpc/perf/imc-pmu.c
@@ -399,6 +399,20 @@ static void nest_imc_counters_release(struct perf_event *event)
/* Take the mutex lock for this node and then decrement the reference count */
mutex_lock(&ref->lock);
+ if (ref->refc == 0) {
+ /*
+ * The scenario where this is true is, when perf session is
+ * started, followed by offlining of all cpus in a given node.
+ *
+ * In the cpuhotplug offline path, ppc_nest_imc_cpu_offline()
+ * function set the ref->count to zero, if the cpu which is
+ * about to offline is the last cpu in a given node and make
+ * an OPAL call to disable the engine in that node.
+ *
+ */
+ mutex_unlock(&ref->lock);
+ return;
+ }
ref->refc--;
if (ref->refc == 0) {
rc = opal_imc_counters_stop(OPAL_IMC_COUNTERS_NEST,
@@ -523,8 +537,8 @@ static int core_imc_mem_init(int cpu, int size)
/* We need only vbase for core counters */
mem_info->vbase = page_address(alloc_pages_node(phys_id,
- GFP_KERNEL | __GFP_ZERO | __GFP_THISNODE,
- get_order(size)));
+ GFP_KERNEL | __GFP_ZERO | __GFP_THISNODE |
+ __GFP_NOWARN, get_order(size)));
if (!mem_info->vbase)
return -ENOMEM;
@@ -646,6 +660,20 @@ static void core_imc_counters_release(struct perf_event *event)
return;
mutex_lock(&ref->lock);
+ if (ref->refc == 0) {
+ /*
+ * The scenario where this is true is, when perf session is
+ * started, followed by offlining of all cpus in a given core.
+ *
+ * In the cpuhotplug offline path, ppc_core_imc_cpu_offline()
+ * function set the ref->count to zero, if the cpu which is
+ * about to offline is the last cpu in a given core and make
+ * an OPAL call to disable the engine in that core.
+ *
+ */
+ mutex_unlock(&ref->lock);
+ return;
+ }
ref->refc--;
if (ref->refc == 0) {
rc = opal_imc_counters_stop(OPAL_IMC_COUNTERS_CORE,
@@ -763,8 +791,8 @@ static int thread_imc_mem_alloc(int cpu_id, int size)
* free the memory in cpu offline path.
*/
local_mem = page_address(alloc_pages_node(phys_id,
- GFP_KERNEL | __GFP_ZERO | __GFP_THISNODE,
- get_order(size)));
+ GFP_KERNEL | __GFP_ZERO | __GFP_THISNODE |
+ __GFP_NOWARN, get_order(size)));
if (!local_mem)
return -ENOMEM;
@@ -1148,7 +1176,8 @@ static void imc_common_cpuhp_mem_free(struct imc_pmu *pmu_ptr)
}
/* Only free the attr_groups which are dynamically allocated */
- kfree(pmu_ptr->attr_groups[IMC_EVENT_ATTR]->attrs);
+ if (pmu_ptr->attr_groups[IMC_EVENT_ATTR])
+ kfree(pmu_ptr->attr_groups[IMC_EVENT_ATTR]->attrs);
kfree(pmu_ptr->attr_groups[IMC_EVENT_ATTR]);
kfree(pmu_ptr);
return;