Linux ARM-MSM sub-architecture
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From: Dawei Li <dawei.li@shingroup.cn>
To: will@kernel.org, mark.rutland@arm.com, yury.norov@gmail.com,
	linux@rasmusvillemoes.dk
Cc: xueshuai@linux.alibaba.com, renyu.zj@linux.alibaba.com,
	yangyicong@hisilicon.com, jonathan.cameron@huawei.com,
	andersson@kernel.org, konrad.dybcio@linaro.org,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org,
	Dawei Li <dawei.li@shingroup.cn>
Subject: [PATCH v3 08/10] perf/hisi_uncore: Avoid placing cpumask on the stack
Date: Wed,  3 Apr 2024 23:59:48 +0800	[thread overview]
Message-ID: <20240403155950.2068109-9-dawei.li@shingroup.cn> (raw)
In-Reply-To: <20240403155950.2068109-1-dawei.li@shingroup.cn>

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>
---
 drivers/perf/hisilicon/hisi_uncore_pmu.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/perf/hisilicon/hisi_uncore_pmu.c b/drivers/perf/hisilicon/hisi_uncore_pmu.c
index 04031450d5fe..ccc9191ad1b6 100644
--- 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;
 
-- 
2.27.0


  parent reply	other threads:[~2024-04-03 16:03 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-04-03 15:59 [PATCH v3 00/10] perf: Avoid placing cpumask on the stack Dawei Li
2024-04-03 15:59 ` [PATCH v3 01/10] cpumask: add cpumask_any_and_but() Dawei Li
2024-04-03 16:31   ` Yury Norov
2024-04-03 15:59 ` [PATCH v3 02/10] perf/alibaba_uncore_drw: Avoid placing cpumask on the stack Dawei Li
2024-04-08  0:28   ` Shuai Xue
2024-04-03 15:59 ` [PATCH v3 03/10] perf/arm-cmn: " Dawei Li
2024-04-03 15:59 ` [PATCH v3 04/10] perf/arm_cspmu: " Dawei Li
2024-04-03 15:59 ` [PATCH v3 05/10] perf/arm_dsu: " Dawei Li
2024-04-03 15:59 ` [PATCH v3 06/10] perf/dwc_pcie: " Dawei Li
2024-04-08  0:30   ` Shuai Xue
2024-04-03 15:59 ` [PATCH v3 07/10] perf/hisi_pcie: " Dawei Li
2024-04-05  9:54   ` Jonathan Cameron
2024-04-03 15:59 ` Dawei Li [this message]
2024-04-05  9:54   ` [PATCH v3 08/10] perf/hisi_uncore: " Jonathan Cameron
2024-04-03 15:59 ` [PATCH v3 09/10] perf/qcom_l2: " Dawei Li
2024-04-03 15:59 ` [PATCH v3 10/10] perf/thunderx2: " Dawei Li
2024-04-09 16:59 ` [PATCH v3 00/10] perf: " Will Deacon

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