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authorPeter Zijlstra <a.p.zijlstra@chello.nl>2009-07-22 18:05:48 +0200
committerPeter Zijlstra <a.p.zijlstra@chello.nl>2009-07-22 18:05:48 +0200
commit1d2f37945d1b3a14086c5ea802486778b635cf97 (patch)
treeb40a1a596a29acc1511f661c27f284dd06b0bc9d /kernel/perf_counter.c
parent1483b19f8f5e8ad0c8816de368b099322dad4db5 (diff)
parentf1c6a58121f9846ac665b0fbd3cbab90ce8bcbac (diff)
downloadop-kernel-dev-1d2f37945d1b3a14086c5ea802486778b635cf97.zip
op-kernel-dev-1d2f37945d1b3a14086c5ea802486778b635cf97.tar.gz
Merge commit 'tip/perfcounters/core' into perf-counters-for-linus
Diffstat (limited to 'kernel/perf_counter.c')
-rw-r--r--kernel/perf_counter.c36
1 files changed, 17 insertions, 19 deletions
diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c
index f7a8ab9..5c6fae4 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);
}
@@ -4262,15 +4263,12 @@ 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);
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