[PATCH V2 1/2] perf/x86/rapl: Move the pmu allocation out of CPU hotplug

[kan . liang]

From: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>

There are extra codes in the CPU hotplug function to allocate rapl pmus.
The generic PMU hotplug support is hard to be applied.

As long as the rapl pmus can be allocated upfront for each die/socket,
the code doesn't need to be implemented in the CPU hotplug function.
Move the code to the init_rapl_pmus(), and allocate a PMU for each
possible die/socket.

Tested-by: Oliver Sang <oliver.sang@xxxxxxxxx>
Signed-off-by: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
Cc: Dhananjay Ugwekar <Dhananjay.Ugwekar@xxxxxxx>
---
 arch/x86/events/rapl.c | 44 ++++++++++++++++++++++++++++--------------
 1 file changed, 30 insertions(+), 14 deletions(-)

diff --git a/arch/x86/events/rapl.c b/arch/x86/events/rapl.c
index a481a939862e..7764f739fa0a 100644
--- a/arch/x86/events/rapl.c
+++ b/arch/x86/events/rapl.c
@@ -602,19 +602,8 @@ static int rapl_cpu_online(unsigned int cpu)
 	struct rapl_pmu *pmu = cpu_to_rapl_pmu(cpu);
 	int target;
 
-	if (!pmu) {
-		pmu = kzalloc_node(sizeof(*pmu), GFP_KERNEL, cpu_to_node(cpu));
-		if (!pmu)
-			return -ENOMEM;
-
-		raw_spin_lock_init(&pmu->lock);
-		INIT_LIST_HEAD(&pmu->active_list);
-		pmu->pmu = &rapl_pmus->pmu;
-		pmu->timer_interval = ms_to_ktime(rapl_timer_ms);
-		rapl_hrtimer_init(pmu);
-
-		rapl_pmus->pmus[rapl_pmu_idx] = pmu;
-	}
+	if (!pmu)
+		return -ENOMEM;
 
 	/*
 	 * Check if there is an online cpu in the package which collects rapl
@@ -707,6 +696,32 @@ static const struct attribute_group *rapl_attr_update[] = {
 	NULL,
 };
 
+static int __init init_rapl_pmu(void)
+{
+	struct rapl_pmu *pmu;
+	int idx;
+
+	for (idx = 0; idx < rapl_pmus->nr_rapl_pmu; idx++) {
+		pmu = kzalloc(sizeof(*pmu), GFP_KERNEL);
+		if (!pmu)
+			goto free;
+
+		raw_spin_lock_init(&pmu->lock);
+		INIT_LIST_HEAD(&pmu->active_list);
+		pmu->pmu = &rapl_pmus->pmu;
+		pmu->timer_interval = ms_to_ktime(rapl_timer_ms);
+		rapl_hrtimer_init(pmu);
+
+		rapl_pmus->pmus[idx] = pmu;
+	}
+
+	return 0;
+free:
+	for (; idx > 0; idx--)
+		kfree(rapl_pmus->pmus[idx - 1]);
+	return -ENOMEM;
+}
+
 static int __init init_rapl_pmus(void)
 {
 	int nr_rapl_pmu = topology_max_packages();
@@ -730,7 +745,8 @@ static int __init init_rapl_pmus(void)
 	rapl_pmus->pmu.read		= rapl_pmu_event_read;
 	rapl_pmus->pmu.module		= THIS_MODULE;
 	rapl_pmus->pmu.capabilities	= PERF_PMU_CAP_NO_EXCLUDE;
-	return 0;
+
+	return init_rapl_pmu();
 }
 
 static struct rapl_model model_snb = {
-- 
2.38.1