[PATCH v2 3/6] perf/core: Don't pass task around when ctx sched in
From: Chengming Zhou
Date: Tue Mar 22 2022 - 08:10:24 EST
The current code pass task around for ctx_sched_in(), only
to get perf_cgroup of the task, then update the timestamp
of it and its ancestors and set them to active.
But we can use cpuctx->cgrp to get active perf_cgroup and
its ancestors since cpuctx->cgrp has been set before
ctx_sched_in().
This patch remove the task argument in ctx_sched_in()
and cleanup related code.
Signed-off-by: Chengming Zhou <zhouchengming@xxxxxxxxxxxxx>
---
kernel/events/core.c | 54 ++++++++++++++++++++------------------------
1 file changed, 24 insertions(+), 30 deletions(-)
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 848a3bfa9513..e27c06628bad 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -574,8 +574,7 @@ static void cpu_ctx_sched_out(struct perf_cpu_context *cpuctx,
enum event_type_t event_type);
static void cpu_ctx_sched_in(struct perf_cpu_context *cpuctx,
- enum event_type_t event_type,
- struct task_struct *task);
+ enum event_type_t event_type);
static void update_context_time(struct perf_event_context *ctx);
static u64 perf_event_time(struct perf_event *event);
@@ -801,10 +800,10 @@ static inline void update_cgrp_time_from_event(struct perf_event *event)
}
static inline void
-perf_cgroup_set_timestamp(struct task_struct *task,
- struct perf_event_context *ctx)
+perf_cgroup_set_timestamp(struct perf_cpu_context *cpuctx)
{
- struct perf_cgroup *cgrp;
+ struct perf_event_context *ctx = &cpuctx->ctx;
+ struct perf_cgroup *cgrp = cpuctx->cgrp;
struct perf_cgroup_info *info;
struct cgroup_subsys_state *css;
@@ -813,10 +812,10 @@ perf_cgroup_set_timestamp(struct task_struct *task,
* ensure we do not access cgroup data
* unless we have the cgroup pinned (css_get)
*/
- if (!task || !ctx->nr_cgroups)
+ if (!cgrp)
return;
- cgrp = perf_cgroup_from_task(task, ctx);
+ WARN_ON_ONCE(!ctx->nr_cgroups);
for (css = &cgrp->css; css; css = css->parent) {
cgrp = container_of(css, struct perf_cgroup, css);
@@ -873,7 +872,7 @@ static void perf_cgroup_switch(struct task_struct *task)
* event_filter_match() to not have to pass
* task around
*/
- cpu_ctx_sched_in(cpuctx, EVENT_ALL, task);
+ cpu_ctx_sched_in(cpuctx, EVENT_ALL);
perf_pmu_enable(cpuctx->ctx.pmu);
perf_ctx_unlock(cpuctx, cpuctx->task_ctx);
@@ -1057,8 +1056,7 @@ static inline int perf_cgroup_connect(pid_t pid, struct perf_event *event,
}
static inline void
-perf_cgroup_set_timestamp(struct task_struct *task,
- struct perf_event_context *ctx)
+perf_cgroup_set_timestamp(struct perf_cpu_context *cpuctx)
{
}
@@ -2651,8 +2649,7 @@ static void ctx_sched_out(struct perf_event_context *ctx,
static void
ctx_sched_in(struct perf_event_context *ctx,
struct perf_cpu_context *cpuctx,
- enum event_type_t event_type,
- struct task_struct *task);
+ enum event_type_t event_type);
static void task_ctx_sched_out(struct perf_cpu_context *cpuctx,
struct perf_event_context *ctx,
@@ -2668,15 +2665,14 @@ static void task_ctx_sched_out(struct perf_cpu_context *cpuctx,
}
static void perf_event_sched_in(struct perf_cpu_context *cpuctx,
- struct perf_event_context *ctx,
- struct task_struct *task)
+ struct perf_event_context *ctx)
{
- cpu_ctx_sched_in(cpuctx, EVENT_PINNED, task);
+ cpu_ctx_sched_in(cpuctx, EVENT_PINNED);
if (ctx)
- ctx_sched_in(ctx, cpuctx, EVENT_PINNED, task);
- cpu_ctx_sched_in(cpuctx, EVENT_FLEXIBLE, task);
+ ctx_sched_in(ctx, cpuctx, EVENT_PINNED);
+ cpu_ctx_sched_in(cpuctx, EVENT_FLEXIBLE);
if (ctx)
- ctx_sched_in(ctx, cpuctx, EVENT_FLEXIBLE, task);
+ ctx_sched_in(ctx, cpuctx, EVENT_FLEXIBLE);
}
/*
@@ -2726,7 +2722,7 @@ static void ctx_resched(struct perf_cpu_context *cpuctx,
else if (ctx_event_type & EVENT_PINNED)
cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE);
- perf_event_sched_in(cpuctx, task_ctx, current);
+ perf_event_sched_in(cpuctx, task_ctx);
perf_pmu_enable(cpuctx->ctx.pmu);
}
@@ -2949,7 +2945,7 @@ static void __perf_event_enable(struct perf_event *event,
return;
if (!event_filter_match(event)) {
- ctx_sched_in(ctx, cpuctx, EVENT_TIME, current);
+ ctx_sched_in(ctx, cpuctx, EVENT_TIME);
return;
}
@@ -2958,7 +2954,7 @@ static void __perf_event_enable(struct perf_event *event,
* then don't put it on unless the group is on.
*/
if (leader != event && leader->state != PERF_EVENT_STATE_ACTIVE) {
- ctx_sched_in(ctx, cpuctx, EVENT_TIME, current);
+ ctx_sched_in(ctx, cpuctx, EVENT_TIME);
return;
}
@@ -3803,8 +3799,7 @@ ctx_flexible_sched_in(struct perf_event_context *ctx,
static void
ctx_sched_in(struct perf_event_context *ctx,
struct perf_cpu_context *cpuctx,
- enum event_type_t event_type,
- struct task_struct *task)
+ enum event_type_t event_type)
{
int is_active = ctx->is_active;
@@ -3816,7 +3811,7 @@ ctx_sched_in(struct perf_event_context *ctx,
if (is_active ^ EVENT_TIME) {
/* start ctx time */
__update_context_time(ctx, false);
- perf_cgroup_set_timestamp(task, ctx);
+ perf_cgroup_set_timestamp(cpuctx);
/*
* CPU-release for the below ->is_active store,
* see __load_acquire() in perf_event_time_now()
@@ -3847,12 +3842,11 @@ ctx_sched_in(struct perf_event_context *ctx,
}
static void cpu_ctx_sched_in(struct perf_cpu_context *cpuctx,
- enum event_type_t event_type,
- struct task_struct *task)
+ enum event_type_t event_type)
{
struct perf_event_context *ctx = &cpuctx->ctx;
- ctx_sched_in(ctx, cpuctx, event_type, task);
+ ctx_sched_in(ctx, cpuctx, event_type);
}
static void perf_event_context_sched_in(struct perf_event_context *ctx,
@@ -3894,7 +3888,7 @@ static void perf_event_context_sched_in(struct perf_event_context *ctx,
*/
if (!RB_EMPTY_ROOT(&ctx->pinned_groups.tree))
cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE);
- perf_event_sched_in(cpuctx, ctx, task);
+ perf_event_sched_in(cpuctx, ctx);
if (cpuctx->sched_cb_usage && pmu->sched_task)
pmu->sched_task(cpuctx->task_ctx, true);
@@ -4195,7 +4189,7 @@ static bool perf_rotate_context(struct perf_cpu_context *cpuctx)
if (cpu_event)
rotate_ctx(&cpuctx->ctx, cpu_event);
- perf_event_sched_in(cpuctx, task_ctx, current);
+ perf_event_sched_in(cpuctx, task_ctx);
perf_pmu_enable(cpuctx->ctx.pmu);
perf_ctx_unlock(cpuctx, cpuctx->task_ctx);
@@ -4267,7 +4261,7 @@ static void perf_event_enable_on_exec(int ctxn)
clone_ctx = unclone_ctx(ctx);
ctx_resched(cpuctx, ctx, event_type);
} else {
- ctx_sched_in(ctx, cpuctx, EVENT_TIME, current);
+ ctx_sched_in(ctx, cpuctx, EVENT_TIME);
}
perf_ctx_unlock(cpuctx, ctx);
--
2.20.1