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

[kan . liang]

From: Kan Liang <kan.li...@linux.intel.com>

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.li...@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