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perf/arm-cmn: Account for NUMA affinity

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On a system with multiple CMN meshes, ideally we'd want to access each
PMU from within its own mesh, rather than with a long CML round-trip,
wherever feasible. Since such a system is likely to be presented as
multiple NUMA nodes, let's also hope a proximity domain is specified
for each CMN programming interface, and use that to guide our choice
of IRQ affinity to favour a node-local CPU where possible.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/32438b0d016e0649d882d47d30ac2000484287b9.1638530442.git.robin.murphy@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
This commit is contained in:
Robin Murphy 2021-12-03 11:44:51 +00:00 committed by Will Deacon
parent 56c7c6eaf3
commit 6190741c29
1 changed files with 38 additions and 13 deletions
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51
drivers/perf/arm-cmn.c
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@ -1147,23 +1147,47 @@ static int arm_cmn_commit_txn(struct pmu *pmu)
return 0;
}
static int arm_cmn_pmu_offline_cpu(unsigned int cpu, struct hlist_node *node)
static void arm_cmn_migrate(struct arm_cmn *cmn, unsigned int cpu)
{
unsigned int i;
perf_pmu_migrate_context(&cmn->pmu, cmn->cpu, cpu);
for (i = 0; i < cmn->num_dtcs; i++)
irq_set_affinity(cmn->dtc[i].irq, cpumask_of(cpu));
cmn->cpu = cpu;
}
static int arm_cmn_pmu_online_cpu(unsigned int cpu, struct hlist_node *cpuhp_node)
{
struct arm_cmn *cmn;
unsigned int i, target;
int node;
cmn = hlist_entry_safe(node, struct arm_cmn, cpuhp_node);
cmn = hlist_entry_safe(cpuhp_node, struct arm_cmn, cpuhp_node);
node = dev_to_node(cmn->dev);
if (node != NUMA_NO_NODE && cpu_to_node(cmn->cpu) != node && cpu_to_node(cpu) == node)
arm_cmn_migrate(cmn, cpu);
return 0;
}
static int arm_cmn_pmu_offline_cpu(unsigned int cpu, struct hlist_node *cpuhp_node)
{
struct arm_cmn *cmn;
unsigned int target;
int node;
cpumask_t mask;
cmn = hlist_entry_safe(cpuhp_node, struct arm_cmn, cpuhp_node);
if (cpu != cmn->cpu)
return 0;
target = cpumask_any_but(cpu_online_mask, cpu);
if (target >= nr_cpu_ids)
return 0;
perf_pmu_migrate_context(&cmn->pmu, cpu, target);
for (i = 0; i < cmn->num_dtcs; i++)
irq_set_affinity(cmn->dtc[i].irq, cpumask_of(target));
cmn->cpu = target;
node = dev_to_node(cmn->dev);
if (cpumask_and(&mask, cpumask_of_node(node), cpu_online_mask) &&
cpumask_andnot(&mask, &mask, cpumask_of(cpu)))
target = cpumask_any(&mask);
else
target = cpumask_any_but(cpu_online_mask, cpu);
if (target < nr_cpu_ids)
arm_cmn_migrate(cmn, target);
return 0;
}
@ -1532,7 +1556,7 @@ static int arm_cmn_probe(struct platform_device *pdev)
if (err)
return err;
cmn->cpu = raw_smp_processor_id();
cmn->cpu = cpumask_local_spread(0, dev_to_node(cmn->dev));
cmn->pmu = (struct pmu) {
.module = THIS_MODULE,
.attr_groups = arm_cmn_attr_groups,
@ -1608,7 +1632,8 @@ static int __init arm_cmn_init(void)
int ret;
ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN,
"perf/arm/cmn:online", NULL,
"perf/arm/cmn:online",
arm_cmn_pmu_online_cpu,
arm_cmn_pmu_offline_cpu);
if (ret < 0)
return ret;