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perf/arm_cspmu: Avoid placing cpumask on the stack

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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>
Link: https://lore.kernel.org/r/20240403155950.2068109-5-dawei.li@shingroup.cn
Signed-off-by: Will Deacon <will@kernel.org>
This commit is contained in:
Dawei Li
2024-04-03 23:59:44 +08:00
committed by Will Deacon
parent 60c73240f3
commit b5310fa1fe
1 changed files with 3 additions and 5 deletions
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8
drivers/perf/arm_cspmu/arm_cspmu.c
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@@ -1322,8 +1322,7 @@ static int arm_cspmu_cpu_online(unsigned int cpu, struct hlist_node *node)
static int arm_cspmu_cpu_teardown(unsigned int cpu, struct hlist_node *node) static int arm_cspmu_cpu_teardown(unsigned int cpu, struct hlist_node *node)
{ {
int dst; unsigned int dst;
struct cpumask online_supported;
struct arm_cspmu *cspmu = struct arm_cspmu *cspmu =
hlist_entry_safe(node, struct arm_cspmu, cpuhp_node); hlist_entry_safe(node, struct arm_cspmu, cpuhp_node);
@@ -1333,9 +1332,8 @@ static int arm_cspmu_cpu_teardown(unsigned int cpu, struct hlist_node *node)
return 0; return 0;
/* Choose a new CPU to migrate ownership of the PMU to */ /* Choose a new CPU to migrate ownership of the PMU to */
cpumask_and(&online_supported, &cspmu->associated_cpus, dst = cpumask_any_and_but(&cspmu->associated_cpus,
cpu_online_mask); cpu_online_mask, cpu);
dst = cpumask_any_but(&online_supported, cpu);
if (dst >= nr_cpu_ids) if (dst >= nr_cpu_ids)
return 0; return 0;