[PATCH V6 5/6] perf/x86: Remove swap_task_ctx()

From: kan . liang
Date: Tue Jul 20 2021 - 09:48:35 EST


From: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>

The pmu specific data is saved in task_struct now. It doesn't need to
swap between context.

Remove swap_task_ctx() support.

Reviewed-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Signed-off-by: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
---

No changes since V4

Changes since V3:
- Rebase on top of the 5.13-rc2

arch/x86/events/core.c | 9 ---------
arch/x86/events/intel/core.c | 7 -------
arch/x86/events/intel/lbr.c | 23 -----------------------
arch/x86/events/perf_event.h | 11 -----------
4 files changed, 50 deletions(-)

diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
index 0d4dd78..d59ce9c 100644
--- a/arch/x86/events/core.c
+++ b/arch/x86/events/core.c
@@ -79,7 +79,6 @@ DEFINE_STATIC_CALL_NULL(x86_pmu_commit_scheduling, *x86_pmu.commit_scheduling);
DEFINE_STATIC_CALL_NULL(x86_pmu_stop_scheduling, *x86_pmu.stop_scheduling);

DEFINE_STATIC_CALL_NULL(x86_pmu_sched_task, *x86_pmu.sched_task);
-DEFINE_STATIC_CALL_NULL(x86_pmu_swap_task_ctx, *x86_pmu.swap_task_ctx);

DEFINE_STATIC_CALL_NULL(x86_pmu_drain_pebs, *x86_pmu.drain_pebs);
DEFINE_STATIC_CALL_NULL(x86_pmu_pebs_aliases, *x86_pmu.pebs_aliases);
@@ -2018,7 +2017,6 @@ static void x86_pmu_static_call_update(void)
static_call_update(x86_pmu_stop_scheduling, x86_pmu.stop_scheduling);

static_call_update(x86_pmu_sched_task, x86_pmu.sched_task);
- static_call_update(x86_pmu_swap_task_ctx, x86_pmu.swap_task_ctx);

static_call_update(x86_pmu_drain_pebs, x86_pmu.drain_pebs);
static_call_update(x86_pmu_pebs_aliases, x86_pmu.pebs_aliases);
@@ -2633,12 +2631,6 @@ static void x86_pmu_sched_task(struct perf_event_context *ctx,
static_call_cond(x86_pmu_sched_task)(ctx, task, sched_in);
}

-static void x86_pmu_swap_task_ctx(struct perf_event_context *prev,
- struct perf_event_context *next)
-{
- static_call_cond(x86_pmu_swap_task_ctx)(prev, next);
-}
-
void perf_check_microcode(void)
{
if (x86_pmu.check_microcode)
@@ -2700,7 +2692,6 @@ static struct pmu pmu = {

.event_idx = x86_pmu_event_idx,
.sched_task = x86_pmu_sched_task,
- .swap_task_ctx = x86_pmu_swap_task_ctx,
.check_period = x86_pmu_check_period,

.aux_output_match = x86_pmu_aux_output_match,
diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
index 42b0c6c..a0dfa82 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -4477,12 +4477,6 @@ static void intel_pmu_sched_task(struct perf_event_context *ctx,
intel_pmu_lbr_sched_task(ctx, task, sched_in);
}

-static void intel_pmu_swap_task_ctx(struct perf_event_context *prev,
- struct perf_event_context *next)
-{
- intel_pmu_lbr_swap_task_ctx(prev, next);
-}
-
static int intel_pmu_check_period(struct perf_event *event, u64 value)
{
return intel_pmu_has_bts_period(event, value) ? -EINVAL : 0;
@@ -4631,7 +4625,6 @@ static __initconst const struct x86_pmu intel_pmu = {

.guest_get_msrs = intel_guest_get_msrs,
.sched_task = intel_pmu_sched_task,
- .swap_task_ctx = intel_pmu_swap_task_ctx,

.check_period = intel_pmu_check_period,

diff --git a/arch/x86/events/intel/lbr.c b/arch/x86/events/intel/lbr.c
index 8248ae1..a56068c 100644
--- a/arch/x86/events/intel/lbr.c
+++ b/arch/x86/events/intel/lbr.c
@@ -602,29 +602,6 @@ static void __intel_pmu_lbr_save(void *ctx)
cpuc->last_log_id = ++task_context_opt(ctx)->log_id;
}

-void intel_pmu_lbr_swap_task_ctx(struct perf_event_context *prev,
- struct perf_event_context *next)
-{
- void *prev_ctx_data, *next_ctx_data;
-
- swap(prev->task_ctx_data, next->task_ctx_data);
-
- /*
- * Architecture specific synchronization makes sense in
- * case both prev->task_ctx_data and next->task_ctx_data
- * pointers are allocated.
- */
-
- prev_ctx_data = next->task_ctx_data;
- next_ctx_data = prev->task_ctx_data;
-
- if (!prev_ctx_data || !next_ctx_data)
- return;
-
- swap(task_context_opt(prev_ctx_data)->lbr_callstack_users,
- task_context_opt(next_ctx_data)->lbr_callstack_users);
-}
-
void intel_pmu_lbr_sched_task(struct perf_event_context *ctx,
struct task_struct *task, bool sched_in)
{
diff --git a/arch/x86/events/perf_event.h b/arch/x86/events/perf_event.h
index 583c08d38..bc8836b 100644
--- a/arch/x86/events/perf_event.h
+++ b/arch/x86/events/perf_event.h
@@ -855,14 +855,6 @@ struct x86_pmu {
int (*set_topdown_event_period)(struct perf_event *event);

/*
- * perf task context (i.e. struct perf_event_context::task_ctx_data)
- * switch helper to bridge calls from perf/core to perf/x86.
- * See struct pmu::swap_task_ctx() usage for examples;
- */
- void (*swap_task_ctx)(struct perf_event_context *prev,
- struct perf_event_context *next);
-
- /*
* AMD bits
*/
unsigned int amd_nb_constraints : 1;
@@ -1307,9 +1299,6 @@ void intel_pmu_store_pebs_lbrs(struct lbr_entry *lbr);

void intel_ds_init(void);

-void intel_pmu_lbr_swap_task_ctx(struct perf_event_context *prev,
- struct perf_event_context *next);
-
void intel_pmu_lbr_sched_task(struct perf_event_context *ctx,
struct task_struct *task, bool sched_in);

--
2.7.4