Commit 3821f258 authored by Peter Zijlstra's avatar Peter Zijlstra
Browse files

perf: Merge consecutive conditionals in perf_mmap() 



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

  if (cond) {
    C;
  } else {
    D;
  }

into:

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

Notably the conditions are not identical in form, but are equivalent.

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/20250812104018.900078502@infradead.org
parent 86a0a7c5

kernel/events/core.c

+19 −22
Original line number Diff line number Diff line
@@ -7064,6 +7064,25 @@ static int perf_mmap(struct file *file, struct vm_area_struct *vma) 
		if (vma->vm_flags & VM_WRITE)

			flags |= RING_BUFFER_WRITABLE;



		rb = rb_alloc(nr_pages,

			      event->attr.watermark ? event->attr.wakeup_watermark : 0,

			      event->cpu, flags);



		if (!rb) {

			ret = -ENOMEM;

			goto unlock;

		}



		atomic_set(&rb->mmap_count, 1);

		rb->mmap_user = get_current_user();

		rb->mmap_locked = extra;



		ring_buffer_attach(event, rb);



		perf_event_update_time(event);

		perf_event_init_userpage(event);

		perf_event_update_userpage(event);

		ret = 0;

	} else {

		/*

		 * AUX area mapping: if rb->aux_nr_pages != 0, it's already
@@ -7120,29 +7139,7 @@ static int perf_mmap(struct file *file, struct vm_area_struct *vma) 


		if (vma->vm_flags & VM_WRITE)

			flags |= RING_BUFFER_WRITABLE;

	}



	if (!rb) {

		rb = rb_alloc(nr_pages,

			      event->attr.watermark ? event->attr.wakeup_watermark : 0,

			      event->cpu, flags);



		if (!rb) {

			ret = -ENOMEM;

			goto unlock;

		}



		atomic_set(&rb->mmap_count, 1);

		rb->mmap_user = get_current_user();

		rb->mmap_locked = extra;



		ring_buffer_attach(event, rb);



		perf_event_update_time(event);

		perf_event_init_userpage(event);

		perf_event_update_userpage(event);

		ret = 0;

	} else {

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

				   event->attr.aux_watermark, flags);

		if (!ret) {