[PATCH 13/21] perf/core: Factor out functions to allocate/free the task_ctx_data

kan.liang
2020-06-19T14:08:29Z

The method to allocate/free the task_ctx_data is going to be changed in
the following patch. Currently, the task_ctx_data is allocated/freed in
several different places. To avoid repeatedly modifying the same codes
in several different places, alloc_task_ctx_data() and
free_task_ctx_data() are factored out to allocate/free the
task_ctx_data. The modification only needs to be applied once.

Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
---
kernel/events/core.c | 21 +++++++++++++++------
1 file changed, 15 insertions(+), 6 deletions(-)

diff --git a/kernel/events/core.c b/kernel/events/core.c
index 633b4ae..a9bfe32 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -1234,12 +1234,22 @@ static void get_ctx(struct perf_event_context *ctx)
refcount_inc(&ctx->refcount);
}

+static void *alloc_task_ctx_data(struct pmu *pmu)
+{
+ return kzalloc(pmu->task_ctx_size, GFP_KERNEL);
+}
+
+static void free_task_ctx_data(struct pmu *pmu, void *task_ctx_data)
+{
+ kfree(task_ctx_data);
+}
+
static void free_ctx(struct rcu_head *head)
{
struct perf_event_context *ctx;

ctx = container_of(head, struct perf_event_context, rcu_head);
- kfree(ctx->task_ctx_data);
+ free_task_ctx_data(ctx->pmu, ctx->task_ctx_data);
kfree(ctx);
}

@@ -4467,7 +4477,7 @@ find_get_context(struct pmu *pmu, struct task_struct *task,
goto errout;

if (event->attach_state & PERF_ATTACH_TASK_DATA) {
- task_ctx_data = kzalloc(pmu->task_ctx_size, GFP_KERNEL);
+ task_ctx_data = alloc_task_ctx_data(pmu);
if (!task_ctx_data) {
err = -ENOMEM;
goto errout;
@@ -4525,11 +4535,11 @@ find_get_context(struct pmu *pmu, struct task_struct *task,
}
}

- kfree(task_ctx_data);
+ free_task_ctx_data(pmu, task_ctx_data);
return ctx;

errout:
- kfree(task_ctx_data);
+ free_task_ctx_data(pmu, task_ctx_data);
return ERR_PTR(err);
}

@@ -12406,8 +12416,7 @@ inherit_event(struct perf_event *parent_event,
!child_ctx->task_ctx_data) {
struct pmu *pmu = child_event->pmu;

- child_ctx->task_ctx_data = kzalloc(pmu->task_ctx_size,
- GFP_KERNEL);
+ child_ctx->task_ctx_data = alloc_task_ctx_data(pmu);
if (!child_ctx->task_ctx_data) {
free_event(child_event);
return ERR_PTR(-ENOMEM);
--
2.7.4