linux-kernel - [PATCH v3 40/57] perf: Simplify perf_mmap_close()/perf_aux_sample

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Message-ID: <20230612093540.407316252@infradead.org>
Date:   Mon, 12 Jun 2023 11:07:53 +0200
From:   Peter Zijlstra <peterz@...radead.org>
To:     torvalds@...ux-foundation.org, keescook@...omium.org,
        gregkh@...uxfoundation.org, pbonzini@...hat.com
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Subject: [PATCH v3 40/57] perf: Simplify perf_mmap_close()/perf_aux_sample_output()


Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
---
 kernel/events/core.c |   20 ++++++++------------
 1 file changed, 8 insertions(+), 12 deletions(-)

--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -6179,6 +6179,9 @@ void ring_buffer_put(struct perf_buffer
 	call_rcu(&rb->rcu_head, rb_free_rcu);
 }
 
+DEFINE_CLASS(ring_buffer_get, struct perf_buffer *, ring_buffer_put(_T),
+	     ring_buffer_get(event), struct perf_event *event)
+
 static void perf_mmap_open(struct vm_area_struct *vma)
 {
 	struct perf_event *event = vma->vm_file->private_data;
@@ -6206,7 +6209,7 @@ static void perf_pmu_output_stop(struct
 static void perf_mmap_close(struct vm_area_struct *vma)
 {
 	struct perf_event *event = vma->vm_file->private_data;
-	struct perf_buffer *rb = ring_buffer_get(event);
+	CLASS(ring_buffer_get, rb)(event);
 	struct user_struct *mmap_user = rb->mmap_user;
 	int mmap_locked = rb->mmap_locked;
 	unsigned long size = perf_data_size(rb);
@@ -6245,14 +6248,14 @@ static void perf_mmap_close(struct vm_ar
 		detach_rest = true;
 
 	if (!atomic_dec_and_mutex_lock(&event->mmap_count, &event->mmap_mutex))
-		goto out_put;
+		return;
 
 	ring_buffer_attach(event, NULL);
 	mutex_unlock(&event->mmap_mutex);
 
 	/* If there's still other mmap()s of this buffer, we're done. */
 	if (!detach_rest)
-		goto out_put;
+		return;
 
 	/*
 	 * No other mmap()s, detach from all other events that might redirect
@@ -6309,9 +6312,6 @@ static void perf_mmap_close(struct vm_ar
 			&mmap_user->locked_vm);
 	atomic64_sub(mmap_locked, &vma->vm_mm->pinned_vm);
 	free_uid(mmap_user);
-
-out_put:
-	ring_buffer_put(rb); /* could be last */
 }
 
 static const struct vm_operations_struct perf_mmap_vmops = {
@@ -6962,14 +6962,13 @@ static void perf_aux_sample_output(struc
 				   struct perf_sample_data *data)
 {
 	struct perf_event *sampler = event->aux_event;
-	struct perf_buffer *rb;
 	unsigned long pad;
 	long size;
 
 	if (WARN_ON_ONCE(!sampler || !data->aux_size))
 		return;
 
-	rb = ring_buffer_get(sampler);
+	CLASS(ring_buffer_get, rb)(sampler);
 	if (!rb)
 		return;
 
@@ -6982,7 +6981,7 @@ static void perf_aux_sample_output(struc
 	 * like to know.
 	 */
 	if (WARN_ON_ONCE(size < 0))
-		goto out_put;
+		return;
 
 	/*
 	 * The pad comes from ALIGN()ing data->aux_size up to u64 in
@@ -6996,9 +6995,6 @@ static void perf_aux_sample_output(struc
 		u64 zero = 0;
 		perf_output_copy(handle, &zero, pad);
 	}
-
-out_put:
-	ring_buffer_put(rb);
 }
 
 /*