[PATCH 06/13] perf; Simplify event_sched_in()

Peter Zijlstra
2023-11-02T15:33:00Z

Use guards to reduce gotos and simplify control flow.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
kernel/events/core.c | 13 +++++--------
1 file changed, 5 insertions(+), 8 deletions(-)

--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -1153,6 +1153,8 @@ void perf_pmu_enable(struct pmu *pmu)
pmu->pmu_enable(pmu);
}

+DEFINE_GUARD(perf_pmu_disable, struct pmu *, perf_pmu_disable(_T), perf_pmu_enable(_T))
+
static void perf_assert_pmu_disabled(struct pmu *pmu)
{
WARN_ON_ONCE(*this_cpu_ptr(pmu->pmu_disable_count) == 0);
@@ -2489,7 +2491,6 @@ event_sched_in(struct perf_event *event,
{
struct perf_event_pmu_context *epc = event->pmu_ctx;
struct perf_cpu_pmu_context *cpc = this_cpu_ptr(epc->pmu->cpu_pmu_context);
- int ret = 0;

WARN_ON_ONCE(event->ctx != ctx);

@@ -2517,15 +2518,14 @@ event_sched_in(struct perf_event *event,
event->hw.interrupts = 0;
}

- perf_pmu_disable(event->pmu);
+ guard(perf_pmu_disable)(event->pmu);

perf_log_itrace_start(event);

if (event->pmu->add(event, PERF_EF_START)) {
perf_event_set_state(event, PERF_EVENT_STATE_INACTIVE);
event->oncpu = -1;
- ret = -EAGAIN;
- goto out;
+ return -EAGAIN;
}

if (!is_software_event(event))
@@ -2536,10 +2536,7 @@ event_sched_in(struct perf_event *event,
if (event->attr.exclusive)
cpc->exclusive = 1;

-out:
- perf_pmu_enable(event->pmu);
-
- return ret;
+ return 0;
}

static int