[PATCH v3 40/57] perf: Simplify perf_mmap_close()/perf_aux_sample_output()

From: Peter Zijlstra
Date: Mon Jun 12 2023 - 06:01:02 EST



Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
---
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);
}

/*