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Message-Id: <20220325035318.42168-2-zhouchengming@bytedance.com>
Date: Fri, 25 Mar 2022 11:53:14 +0800
From: Chengming Zhou <zhouchengming@...edance.com>
To: peterz@...radead.org, mingo@...hat.com, acme@...nel.org,
mark.rutland@....com, alexander.shishkin@...ux.intel.com,
jolsa@...nel.org, namhyung@...nel.org, eranian@...gle.com
Cc: linux-perf-users@...r.kernel.org, linux-kernel@...r.kernel.org,
duanxiongchun@...edance.com, songmuchun@...edance.com,
Chengming Zhou <zhouchengming@...edance.com>
Subject: [PATCH v3 1/5] perf/core: Don't pass task around when ctx sched in
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@...edance.com>
---
kernel/events/core.c | 58 ++++++++++++++++++++------------------------
1 file changed, 26 insertions(+), 32 deletions(-)
diff --git a/kernel/events/core.c b/kernel/events/core.c
index cfde994ce61c..d50f45012c05 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);
@@ -869,14 +868,14 @@ static void perf_cgroup_switch(struct task_struct *task, int mode)
WARN_ON_ONCE(cpuctx->cgrp);
/*
* set cgrp before ctxsw in to allow
- * event_filter_match() to not have to pass
- * task around
+ * perf_cgroup_set_timestamp() in ctx_sched_in()
+ * to not have to pass task around
* we pass the cpuctx->ctx to perf_cgroup_from_task()
* because cgorup events are only per-cpu
*/
cpuctx->cgrp = perf_cgroup_from_task(task,
&cpuctx->ctx);
- 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);
@@ -1118,8 +1117,7 @@ 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)
{
}
@@ -2713,8 +2711,7 @@ 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,
@@ -2730,15 +2727,14 @@ 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);
}
/*
@@ -2788,7 +2784,7 @@ 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);
}
@@ -3011,7 +3007,7 @@ 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;
}
@@ -3020,7 +3016,7 @@ 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;
}
@@ -3865,8 +3861,7 @@ 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;
@@ -3878,7 +3873,7 @@ 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()
@@ -3909,12 +3904,11 @@ 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,
@@ -3956,7 +3950,7 @@ 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);
@@ -4267,7 +4261,7 @@ 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);
@@ -4339,7 +4333,7 @@ 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
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