@@ -471,9 +471,9 @@ static __poll_t xsk_poll(struct file *file, struct socket *sock,
__xsk_sendmsg(sk);
}
- if (xs->rx && !xskq_empty_desc(xs->rx))
+ if (xs->rx && !xskq_prod_is_empty(xs->rx))
mask |= EPOLLIN | EPOLLRDNORM;
- if (xs->tx && !xskq_full_desc(xs->tx))
+ if (xs->tx && !xskq_cons_is_full(xs->tx))
mask |= EPOLLOUT | EPOLLWRNORM;
return mask;
@@ -351,14 +351,16 @@ static inline int xskq_prod_reserve_desc(struct xsk_queue *q,
return 0;
}
-static inline bool xskq_full_desc(struct xsk_queue *q)
+static inline bool xskq_cons_is_full(struct xsk_queue *q)
{
- return xskq_nb_avail(q, q->nentries) == q->nentries;
+ /* No barriers needed since data is not accessed */
+ return READ_ONCE(q->ring->producer) - q->cons_tail == q->nentries;
}
-static inline bool xskq_empty_desc(struct xsk_queue *q)
+static inline bool xskq_prod_is_empty(struct xsk_queue *q)
{
- return xskq_nb_free(q, q->nentries) == q->nentries;
+ /* No barriers needed since data is not accessed */
+ return READ_ONCE(q->ring->consumer) == q->cached_prod;
}
void xskq_set_umem(struct xsk_queue *q, u64 size, u64 chunk_mask);
In order to set the correct return flags for poll, the xsk code has to check if the Rx queue is empty and if the Tx queue is full. This code was unnecessarily large and complex as it used the functions that are used to update the local state from the global state (xskq_nb_free and xskq_nb_avail). Since we are not doing this nor updating any data dependent on this state, we can simplify the functions. Another benefit from this is that we can also simplify the xskq_nb_free and xskq_nb_avail functions in a later commit. Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> --- net/xdp/xsk.c | 4 ++-- net/xdp/xsk_queue.h | 10 ++++++---- 2 files changed, 8 insertions(+), 6 deletions(-)