Performance: Relax atomicity constraints for crash handling

[lttng-ust.git] / libringbuffer / frontend_internal.h

diff --git a/libringbuffer/frontend_internal.h b/libringbuffer/frontend_internal.h
index 43a2d0a2639b29d319ddb7b9d1d417855f9c96bc..c973e6b25f88c1cc905bedfb28463f7cc5499316 100644 (file)
--- a/libringbuffer/frontend_internal.h
+++ b/libringbuffer/frontend_internal.h
@@ -314,9 +314,9 @@ void lib_ring_buffer_write_commit_counter(const struct lttng_ust_lib_ring_buffer
                return;
 
        commit_seq_old = v_read(config, &shmp_index(handle, buf->commit_hot, idx)->seq);
-       while ((long) (commit_seq_old - commit_count) < 0)
-               commit_seq_old = v_cmpxchg(config, &shmp_index(handle, buf->commit_hot, idx)->seq,
-                                          commit_seq_old, commit_count);
+       if (caa_likely((long) (commit_seq_old - commit_count) < 0))
+               v_set(config, &shmp_index(handle, buf->commit_hot, idx)->seq,
+                       commit_count);
 }
 
 extern int lib_ring_buffer_create(struct lttng_ust_lib_ring_buffer *buf,