[PATCH 06/15] kernel: convert perf_event_context.refcount from atomic_t to refcount_t

@@ -54,6 +54,7 @@ struct perf_guest_info_callbacks {
 #include <linux/perf_regs.h>
 #include <linux/workqueue.h>
 #include <linux/cgroup.h>
+#include <linux/refcount.h>
 #include <asm/local.h>
 
 struct perf_callchain_entry {

@@ -750,7 +751,7 @@ struct perf_event_context {
 	int				nr_stat;
 	int				nr_freq;
 	int				rotate_disable;
-	atomic_t			refcount;
+	refcount_t			refcount;
 	struct task_struct		*task;
 
 	/*

@@ -1109,7 +1109,7 @@ static void perf_event_ctx_deactivate(struct perf_event_context *ctx)
 
 static void get_ctx(struct perf_event_context *ctx)
 {
-	WARN_ON(!atomic_inc_not_zero(&ctx->refcount));
+	refcount_inc(&ctx->refcount);
 }
 
 static void free_ctx(struct rcu_head *head)

@@ -1123,7 +1123,7 @@ static void free_ctx(struct rcu_head *head)
 
 static void put_ctx(struct perf_event_context *ctx)
 {
-	if (atomic_dec_and_test(&ctx->refcount)) {
+	if (refcount_dec_and_test(&ctx->refcount)) {
 		if (ctx->parent_ctx)
 			put_ctx(ctx->parent_ctx);
 		if (ctx->task && ctx->task != TASK_TOMBSTONE)

@@ -1201,7 +1201,7 @@ perf_event_ctx_lock_nested(struct perf_event *event, int nesting)
 again:
 	rcu_read_lock();
 	ctx = ACCESS_ONCE(event->ctx);
-	if (!atomic_inc_not_zero(&ctx->refcount)) {
+	if (!refcount_inc_not_zero(&ctx->refcount)) {
 		rcu_read_unlock();
 		goto again;
 	}

@@ -1329,7 +1329,7 @@ perf_lock_task_context(struct task_struct *task, int ctxn, unsigned long *flags)
 		}
 
 		if (ctx->task == TASK_TOMBSTONE ||
-		    !atomic_inc_not_zero(&ctx->refcount)) {
+		    !refcount_inc_not_zero(&ctx->refcount)) {
 			raw_spin_unlock(&ctx->lock);
 			ctx = NULL;
 		} else {

@@ -3760,7 +3760,7 @@ static void __perf_event_init_context(struct perf_event_context *ctx)
 	INIT_LIST_HEAD(&ctx->pinned_groups);
 	INIT_LIST_HEAD(&ctx->flexible_groups);
 	INIT_LIST_HEAD(&ctx->event_list);
-	atomic_set(&ctx->refcount, 1);
+	refcount_set(&ctx->refcount, 1);
 }
 
 static struct perf_event_context *

@@ -9791,7 +9791,7 @@ __perf_event_ctx_lock_double(struct perf_event *group_leader,
 again:
 	rcu_read_lock();
 	gctx = READ_ONCE(group_leader->ctx);
-	if (!atomic_inc_not_zero(&gctx->refcount)) {
+	if (!refcount_inc_not_zero(&gctx->refcount)) {
 		rcu_read_unlock();
 		goto again;
 	}