perf_counter: Stop open coding unclone_ctx

Instead of open coding the unclone context thingy, put it in
a common function.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 17 insertions, 19 deletions

diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c
index d55a50da2347..8bf997d86bf4 100644
--- a/kernel/perf_counter.c
+++ b/kernel/perf_counter.c
@@ -146,6 +146,14 @@ static void put_ctx(struct perf_counter_context *ctx)
         }
 }
 
+static void unclone_ctx(struct perf_counter_context *ctx)
+{
+        if (ctx->parent_ctx) {
+                put_ctx(ctx->parent_ctx);
+                ctx->parent_ctx = NULL;
+        }
+}
+
 /*
  * Get the perf_counter_context for a task and lock it.
  * This has to cope with with the fact that until it is locked,
@@ -1463,10 +1471,8 @@ static void perf_counter_enable_on_exec(struct task_struct *task)
         /*
          * Unclone this context if we enabled any counter.
          */
-        if (enabled && ctx->parent_ctx) {
-                put_ctx(ctx->parent_ctx);
-                ctx->parent_ctx = NULL;
-        }
+        if (enabled)
+                unclone_ctx(ctx);
 
         spin_unlock(&ctx->lock);
 
@@ -1526,7 +1532,6 @@ __perf_counter_init_context(struct perf_counter_context *ctx,
 
 static struct perf_counter_context *find_get_context(pid_t pid, int cpu)
 {
-        struct perf_counter_context *parent_ctx;
         struct perf_counter_context *ctx;
         struct perf_cpu_context *cpuctx;
         struct task_struct *task;
@@ -1586,11 +1591,7 @@ static struct perf_counter_context *find_get_context(pid_t pid, int cpu)
  retry:
         ctx = perf_lock_task_context(task, &flags);
         if (ctx) {
-                parent_ctx = ctx->parent_ctx;
-                if (parent_ctx) {
-                        put_ctx(parent_ctx);
-                        ctx->parent_ctx = NULL;         /* no longer a clone */
-                }
+                unclone_ctx(ctx);
                 spin_unlock_irqrestore(&ctx->lock, flags);
         }
 
@@ -4255,15 +4256,12 @@ void perf_counter_exit_task(struct task_struct *child)
          */
         spin_lock(&child_ctx->lock);
         child->perf_counter_ctxp = NULL;
-        if (child_ctx->parent_ctx) {
-                /*
-                 * This context is a clone; unclone it so it can't get
-                 * swapped to another process while we're removing all
-                 * the counters from it.
-                 */
-                put_ctx(child_ctx->parent_ctx);
-                child_ctx->parent_ctx = NULL;
-        }
+        /*
+         * If this context is a clone; unclone it so it can't get
+         * swapped to another process while we're removing all
+         * the counters from it.
+         */
+        unclone_ctx(child_ctx);
         spin_unlock(&child_ctx->lock);
         local_irq_restore(flags);