diff options
| author | Kan Liang <kan.liang@linux.intel.com> | 2024-08-02 08:16:38 -0700 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2024-09-10 11:44:13 +0200 |
| commit | a48a36b316ae5d3ab83f9b545dba15998e96d59c (patch) | |
| tree | c530a3553531bb4c067e39e1c4a0b4044aa85a65 /kernel | |
| parent | 4ba4f1afb6a9fed8ef896c2363076e36572f71da (diff) | |
perf: Add PERF_EV_CAP_READ_SCOPE
Usually, an event can be read from any CPU of the scope. It doesn't need
to be read from the advertised CPU.
Add a new event cap, PERF_EV_CAP_READ_SCOPE. An event of a PMU with
scope can be read from any active CPU in the scope.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240802151643.1691631-3-kan.liang@linux.intel.com
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/events/core.c | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index 5ff973513fac..2766090de84e 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -4556,16 +4556,24 @@ struct perf_read_data { int ret; }; +static inline const struct cpumask *perf_scope_cpu_topology_cpumask(unsigned int scope, int cpu); + static int __perf_event_read_cpu(struct perf_event *event, int event_cpu) { + int local_cpu = smp_processor_id(); u16 local_pkg, event_pkg; if ((unsigned)event_cpu >= nr_cpu_ids) return event_cpu; - if (event->group_caps & PERF_EV_CAP_READ_ACTIVE_PKG) { - int local_cpu = smp_processor_id(); + if (event->group_caps & PERF_EV_CAP_READ_SCOPE) { + const struct cpumask *cpumask = perf_scope_cpu_topology_cpumask(event->pmu->scope, event_cpu); + + if (cpumask && cpumask_test_cpu(local_cpu, cpumask)) + return local_cpu; + } + if (event->group_caps & PERF_EV_CAP_READ_ACTIVE_PKG) { event_pkg = topology_physical_package_id(event_cpu); local_pkg = topology_physical_package_id(local_cpu); @@ -11905,7 +11913,7 @@ static int perf_try_init_event(struct pmu *pmu, struct perf_event *event) if (cpu >= nr_cpu_ids) ret = -ENODEV; else - event->cpu = cpu; + event->event_caps |= PERF_EV_CAP_READ_SCOPE; } else { ret = -ENODEV; } |