Commit 83037a47 authored by Yicong Yang's avatar Yicong Yang Committed by Will Deacon
Browse files

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: default avatarYicong Yang <yangyicong@hisilicon.com>
Link: https://lore.kernel.org/r/20241210141525.37788-4-yangyicong@huawei.com


Signed-off-by: default avatarWill Deacon <will@kernel.org>
parent f2368a20

drivers/perf/hisilicon/hisi_uncore_pmu.c

+8 −1
Original line number Diff line number Diff line
@@ -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;