perf/hisi_uncore: Avoid placing cpumask on the stack

In general it's preferable to avoid placing cpumasks on the stack, as
for large values of NR_CPUS these can consume significant amounts of
stack space and make stack overflows more likely.

Use cpumask_any_and_but() to avoid the need for a temporary cpumask on
the stack.

Suggested-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Dawei Li <dawei.li@shingroup.cn>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20240403155950.2068109-9-dawei.li@shingroup.cn
Signed-off-by: Will Deacon <will@kernel.org>

diff --git a/drivers/perf/hisilicon/hisi_uncore_pmu.c b/drivers/perf/hisilicon/hisi_uncore_pmu.c
index 04031450d5fecae9c5740deb553f4ce0ea574673..ccc9191ad1b60ba29536e3238bdf2c995d223bb1 100644 (file)
--- a/drivers/perf/hisilicon/hisi_uncore_pmu.c
+++ b/drivers/perf/hisilicon/hisi_uncore_pmu.c
@@ -504,7 +504,6 @@ int hisi_uncore_pmu_offline_cpu(unsigned int cpu, struct hlist_node *node)
 {
        struct hisi_pmu *hisi_pmu = hlist_entry_safe(node, struct hisi_pmu,
                                                     node);
-       cpumask_t pmu_online_cpus;
        unsigned int target;
 
        if (!cpumask_test_and_clear_cpu(cpu, &hisi_pmu->associated_cpus))
@@ -518,9 +517,8 @@ int hisi_uncore_pmu_offline_cpu(unsigned int cpu, struct hlist_node *node)
        hisi_pmu->on_cpu = -1;
 
        /* Choose a new CPU to migrate ownership of the PMU to */
-       cpumask_and(&pmu_online_cpus, &hisi_pmu->associated_cpus,
-                   cpu_online_mask);
-       target = cpumask_any_but(&pmu_online_cpus, cpu);
+       target = cpumask_any_and_but(&hisi_pmu->associated_cpus,
+                                    cpu_online_mask, cpu);
        if (target >= nr_cpu_ids)
                return 0;