diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2025-08-12 12:39:12 +0200 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2025-08-15 13:13:02 +0200 |
| commit | 59741451b49ce9964a9758c19d6f7df2a1255c75 (patch) | |
| tree | 7eb01f580aa95efe9c4ddc7df5fcfedcd531ed50 /kernel | |
| parent | perf: Use scoped_guard() for mmap_mutex in perf_mmap() (diff) | |
| download | linux-59741451b49ce9964a9758c19d6f7df2a1255c75.tar.gz linux-59741451b49ce9964a9758c19d6f7df2a1255c75.zip | |
perf: Identify the 0->1 transition for event::mmap_count
Needed because refcount_inc() doesn't allow the 0->1 transition.
Specifically, this is the case where we've created the RB, this means
there was no RB, and as such there could not have been an mmap.
Additionally we hold mmap_mutex to serialize everything.
This must be the first.
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250812104019.956479989@infradead.org
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/events/core.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index 41941dfadfcb..f6211ab18503 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -7034,7 +7034,7 @@ static int perf_mmap_rb(struct vm_area_struct *vma, struct perf_event *event, perf_event_update_userpage(event); perf_mmap_account(vma, user_extra, extra); - atomic_inc(&event->mmap_count); + atomic_set(&event->mmap_count, 1); return 0; } |