perf/alibaba_uncore_drw: 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>
Reviewed-by: Shuai Xue <xueshuai@linux.alibaba.com>
Link: https://lore.kernel.org/r/20240403155950.2068109-3-dawei.li@shingroup.cn
Signed-off-by: Will Deacon <will@kernel.org>

diff --git a/drivers/perf/alibaba_uncore_drw_pmu.c b/drivers/perf/alibaba_uncore_drw_pmu.c
index a9277dcf90ce0c6bd6ee97edb25b1a5814fc1e48..d4d14b65c4a5337a248b9d7c482208d56870eed2 100644 (file)
--- a/drivers/perf/alibaba_uncore_drw_pmu.c
+++ b/drivers/perf/alibaba_uncore_drw_pmu.c
@@ -746,18 +746,14 @@ static int ali_drw_pmu_offline_cpu(unsigned int cpu, struct hlist_node *node)
        struct ali_drw_pmu_irq *irq;
        struct ali_drw_pmu *drw_pmu;
        unsigned int target;
-       int ret;
-       cpumask_t node_online_cpus;
 
        irq = hlist_entry_safe(node, struct ali_drw_pmu_irq, node);
        if (cpu != irq->cpu)
                return 0;
 
-       ret = cpumask_and(&node_online_cpus,
-                         cpumask_of_node(cpu_to_node(cpu)), cpu_online_mask);
-       if (ret)
-               target = cpumask_any_but(&node_online_cpus, cpu);
-       else
+       target = cpumask_any_and_but(cpumask_of_node(cpu_to_node(cpu)),
+                                    cpu_online_mask, cpu);
+       if (target >= nr_cpu_ids)
                target = cpumask_any_but(cpu_online_mask, cpu);
 
        if (target >= nr_cpu_ids)