[tip: perf/core] perf/x86/rapl: Move the pmu allocation out of CPU hotplug

[tip-bot2 for Kan Liang]

The following commit has been merged into the perf/core branch of tip:

Commit-ID:     351e6ba39e5c851b00d83716ffb4d19b807ecc3d
Gitweb:        https://git.kernel.org/tip/351e6ba39e5c851b00d83716ffb4d19b807ecc3d
Author:        Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
AuthorDate:    Fri, 02 Aug 2024 08:16:42 -07:00
Committer:     Peter Zijlstra <peterz@xxxxxxxxxxxxx>
CommitterDate: Tue, 10 Sep 2024 11:44:14 +02:00

perf/x86/rapl: Move the pmu allocation out of CPU hotplug

The rapl pmu just needs to be allocated once. It doesn't matter to be
allocated at each CPU hotplug, or the global init_rapl_pmus().

Move the pmu allocation to the init_rapl_pmus(). So the generic hotplug
supports can be applied.

Signed-off-by: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20240802151643.1691631-7-kan.liang@xxxxxxxxxxxxxxx
---
 arch/x86/events/rapl.c | 44 ++++++++++++++++++++++++++++-------------
 1 file changed, 31 insertions(+), 13 deletions(-)

diff --git a/arch/x86/events/rapl.c b/arch/x86/events/rapl.c
index b985ca7..d12f3a6 100644
--- a/arch/x86/events/rapl.c
+++ b/arch/x86/events/rapl.c
@@ -568,19 +568,8 @@ 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[topology_logical_die_id(cpu)] = pmu;
-	}
+	if (!pmu)
+		return -ENOMEM;
 
 	/*
 	 * Check if there is an online cpu in the package which collects rapl
@@ -673,6 +662,32 @@ static const struct attribute_group *rapl_attr_update[] = {
 	NULL,
 };
 
+static void __init init_rapl_pmu(void)
+{
+	struct rapl_pmu *pmu;
+	int cpu;
+
+	cpus_read_lock();
+
+	for_each_cpu(cpu, cpu_online_mask) {
+		pmu = cpu_to_rapl_pmu(cpu);
+		if (pmu)
+			continue;
+		pmu = kzalloc_node(sizeof(*pmu), GFP_KERNEL, cpu_to_node(cpu));
+		if (!pmu)
+			continue;
+		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[topology_logical_die_id(cpu)] = pmu;
+	}
+
+	cpus_read_unlock();
+}
+
 static int __init init_rapl_pmus(void)
 {
 	int nr_rapl_pmu = topology_max_packages() * topology_max_dies_per_package();
@@ -693,6 +708,9 @@ 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;
+
+	init_rapl_pmu();
+
 	return 0;
 }