From 83037a47d3aa5f3e35b0c02433a87806e9c34438 Mon Sep 17 00:00:00 2001 From: Yicong Yang Date: Tue, 10 Dec 2024 22:15:18 +0800 Subject: [PATCH] drivers/perf: hisi: Migrate to one online CPU if no associated one online If the selected CPU hisi_pmu::on_cpu goes offline, driver will select a new online CPU from hisi_pmu::associated_cpus, or if no online CPU found the PMU context won't be migrated. However for uncore PMUs the associated CPUs are just a peference and it also works to schedule the events on any online CPUs. So add a fallback to choose an online CPU if no associated CPUs found. Signed-off-by: Yicong Yang Link: https://lore.kernel.org/r/20241210141525.37788-4-yangyicong@huawei.com Signed-off-by: Will Deacon --- drivers/perf/hisilicon/hisi_uncore_pmu.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/perf/hisilicon/hisi_uncore_pmu.c b/drivers/perf/hisilicon/hisi_uncore_pmu.c index 8c404f8b3f39d..c775e4722dac4 100644 --- a/drivers/perf/hisilicon/hisi_uncore_pmu.c +++ b/drivers/perf/hisilicon/hisi_uncore_pmu.c @@ -499,9 +499,16 @@ int hisi_uncore_pmu_offline_cpu(unsigned int cpu, struct hlist_node *node) /* Give up ownership of the PMU */ hisi_pmu->on_cpu = -1; - /* Choose a new CPU to migrate ownership of the PMU to */ + /* + * Migrate ownership of the PMU to a new CPU chosen from PMU's online + * associated CPUs if possible, if no associated CPU online then + * migrate to one online CPU. + */ target = cpumask_any_and_but(&hisi_pmu->associated_cpus, cpu_online_mask, cpu); + if (target >= nr_cpu_ids) + target = cpumask_any_but(cpu_online_mask, cpu); + if (target >= nr_cpu_ids) return 0; -- 2.39.5