diff options
Diffstat (limited to 'src/liburing.h')
| -rw-r--r-- | src/liburing.h | 15 |
1 files changed, 6 insertions, 9 deletions
diff --git a/src/liburing.h b/src/liburing.h index d3fcd15..a350a01 100644 --- a/src/liburing.h +++ b/src/liburing.h @@ -88,11 +88,10 @@ extern int io_uring_register_eventfd(struct io_uring *ring, int fd); extern int io_uring_unregister_eventfd(struct io_uring *ring); #define io_uring_for_each_cqe(ring, head, cqe) \ + /* smp_load_acquire() enforces the order of tail and CQE reads. */ \ for (head = *(ring)->cq.khead; \ - /* See read_barrier() explanation in __io_uring_get_cqe() */ \ - ({read_barrier(); \ - cqe = (head != *(ring)->cq.ktail ? \ - &(ring)->cq.cqes[head & (*(ring)->cq.kring_mask)] : NULL);}); \ + (cqe = (head != smp_load_acquire((ring)->cq.ktail) ? \ + &(ring)->cq.cqes[head & (*(ring)->cq.kring_mask)] : NULL)); \ head++) \ @@ -105,13 +104,11 @@ static inline void io_uring_cq_advance(struct io_uring *ring, if (nr) { struct io_uring_cq *cq = &ring->cq; - (*cq->khead) += nr; - /* - * Ensure that the kernel sees our new head, the kernel has - * the matching read barrier. + * Ensure that the kernel only sees the new value of the head + * index after the CQEs have been read. */ - write_barrier(); + smp_store_release(cq->khead, *cq->khead + nr); } } |