Commit 4118994b authored by Peter Zijlstra's avatar Peter Zijlstra
Browse files

perf: Move common code into both rb and aux branches 



  if (cond) {
    A;
  } else {
    B;
  }
  C;

into

  if (cond) {
    A;
    C;
  } else {
    B;
    C;
  }

Notably C has a success branch and both A and B have two places for
success. For A (rb case), duplicate the success case because later
patches will result in them no longer being identical. For B (aux
case), share using goto (cleaned up later).

Suggested-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: default avatarLorenzo Stoakes <lorenzo.stoakes@oracle.com>
Link: https://lore.kernel.org/r/20250812104019.016252852@infradead.org
parent 3821f258

kernel/events/core.c

+15 −10
Original line number Diff line number Diff line
@@ -7043,6 +7043,8 @@ static int perf_mmap(struct file *file, struct vm_area_struct *vma) 
				ret = 0;

				/* We need the rb to map pages. */

				rb = event->rb;

				perf_mmap_account(vma, user_extra, extra);

				atomic_inc(&event->mmap_count);

				goto unlock;

			}
@@ -7083,6 +7085,9 @@ static int perf_mmap(struct file *file, struct vm_area_struct *vma) 
		perf_event_init_userpage(event);

		perf_event_update_userpage(event);

		ret = 0;



		perf_mmap_account(vma, user_extra, extra);

		atomic_inc(&event->mmap_count);

	} else {

		/*

		 * AUX area mapping: if rb->aux_nr_pages != 0, it's already
@@ -7127,11 +7132,12 @@ static int perf_mmap(struct file *file, struct vm_area_struct *vma) 
		if (rb_has_aux(rb)) {

			atomic_inc(&rb->aux_mmap_count);

			ret = 0;

			goto unlock;

			goto aux_success;

		}



		if (!perf_mmap_calc_limits(vma, &user_extra, &extra)) {

			ret = -EPERM;

			atomic_dec(&rb->mmap_count);

			goto unlock;

		}
@@ -7142,20 +7148,19 @@ static int perf_mmap(struct file *file, struct vm_area_struct *vma) 


		ret = rb_alloc_aux(rb, event, vma->vm_pgoff, nr_pages,

				   event->attr.aux_watermark, flags);

		if (!ret) {

			atomic_set(&rb->aux_mmap_count, 1);

			rb->aux_mmap_locked = extra;

		}

		if (ret) {

			atomic_dec(&rb->mmap_count);

			goto unlock;

		}



unlock:

	if (!ret) {

		atomic_set(&rb->aux_mmap_count, 1);

		rb->aux_mmap_locked = extra;

aux_success:

		perf_mmap_account(vma, user_extra, extra);

		atomic_inc(&event->mmap_count);

	} else if (rb) {

		/* AUX allocation failed */

		atomic_dec(&rb->mmap_count);

	}



unlock:

aux_unlock:

	if (aux_mutex)

		mutex_unlock(aux_mutex);