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>

diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c
index d55a50da2347f5c2177d3fd5cb0f7db28a7ff71b..8bf997d86bf4f4fc856f167d7e006ad9d7ebd36a 100644 (file)
--- 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);