[PATCH v2 1/2] perf/core: add perf_ctx_resched() as global function

From: Stephane Eranian
Date: Mon Apr 08 2019 - 13:33:04 EST


This patch add perf_ctx_resched() a global function that can be called
to force rescheduling of events based on event types. The function locks
both cpuctx and task_ctx internally. This will be used by a subsequent patch.

Signed-off-by: Stephane Eranian <eranian@xxxxxxxxxx>
Change-Id: Icbc05e5f461fd6e091b46778fe62b23f308e2be7
---
include/linux/perf_event.h | 14 ++++++++++++++
kernel/events/core.c | 18 +++++++++---------
2 files changed, 23 insertions(+), 9 deletions(-)

diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 085a95e2582a..ee8a275df0ed 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -822,6 +822,15 @@ struct bpf_perf_event_data_kern {
struct perf_event *event;
};

+enum event_type_t {
+ EVENT_FLEXIBLE = 0x1,
+ EVENT_PINNED = 0x2,
+ EVENT_TIME = 0x4,
+ /* see ctx_resched() for details */
+ EVENT_CPU = 0x8,
+ EVENT_ALL = EVENT_FLEXIBLE | EVENT_PINNED,
+};
+
#ifdef CONFIG_CGROUP_PERF

/*
@@ -888,6 +897,11 @@ extern void perf_sched_cb_dec(struct pmu *pmu);
extern void perf_sched_cb_inc(struct pmu *pmu);
extern int perf_event_task_disable(void);
extern int perf_event_task_enable(void);
+
+extern void perf_ctx_resched(struct perf_cpu_context *cpuctx,
+ struct perf_event_context *task_ctx,
+ enum event_type_t event_type);
+
extern int perf_event_refresh(struct perf_event *event, int refresh);
extern void perf_event_update_userpage(struct perf_event *event);
extern int perf_event_release_kernel(struct perf_event *event);
diff --git a/kernel/events/core.c b/kernel/events/core.c
index dfc4bab0b02b..30474064ec22 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -354,15 +354,6 @@ static void event_function_local(struct perf_event *event, event_f func, void *d
(PERF_SAMPLE_BRANCH_KERNEL |\
PERF_SAMPLE_BRANCH_HV)

-enum event_type_t {
- EVENT_FLEXIBLE = 0x1,
- EVENT_PINNED = 0x2,
- EVENT_TIME = 0x4,
- /* see ctx_resched() for details */
- EVENT_CPU = 0x8,
- EVENT_ALL = EVENT_FLEXIBLE | EVENT_PINNED,
-};
-
/*
* perf_sched_events : >0 events exist
* perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu
@@ -2477,6 +2468,15 @@ static void ctx_resched(struct perf_cpu_context *cpuctx,
perf_pmu_enable(cpuctx->ctx.pmu);
}

+void perf_ctx_resched(struct perf_cpu_context *cpuctx,
+ struct perf_event_context *task_ctx,
+ enum event_type_t event_type)
+{
+ perf_ctx_lock(cpuctx, task_ctx);
+ ctx_resched(cpuctx, task_ctx, event_type);
+ perf_ctx_unlock(cpuctx, task_ctx);
+}
+
/*
* Cross CPU call to install and enable a performance event
*
--
2.21.0.392.gf8f6787159e-goog