On Fri, Jun 30, 2017 at 02:30:47PM +0200, Nélio Laranjeiro wrote:
> On Wed, Jun 28, 2017 at 04:04:00PM -0700, Yongseok Koh wrote:
> > When processing Tx completion, it is more efficient to free buffers in bulk
> > using rte_mempool_put_bulk() if buffers are from a same mempool.
> >
> > Signed-off-by: Yongseok Koh <ys...@mellanox.com>
> > ---
> > drivers/net/mlx5/mlx5_rxtx.c | 36 +++++++++++++++++++++++++++---------
> > 1 file changed, 27 insertions(+), 9 deletions(-)
> >
> > diff --git a/drivers/net/mlx5/mlx5_rxtx.c b/drivers/net/mlx5/mlx5_rxtx.c
> > index 43db06ad8..d81d630f7 100644
> > --- a/drivers/net/mlx5/mlx5_rxtx.c
> > +++ b/drivers/net/mlx5/mlx5_rxtx.c
> > @@ -264,6 +264,8 @@ txq_complete(struct txq *txq)
> > uint16_t cq_ci = txq->cq_ci;
> > volatile struct mlx5_cqe *cqe = NULL;
> > volatile struct mlx5_wqe_ctrl *ctrl;
> > + struct rte_mbuf *m, *free[elts_n];
> > + unsigned int blk_n = 0;
> >
> > do {
> > volatile struct mlx5_cqe *tmp;
> > @@ -296,21 +298,37 @@ txq_complete(struct txq *txq)
> > assert((elts_tail & elts_m) < (1 << txq->wqe_n));
> > /* Free buffers. */
> > while (elts_free != elts_tail) {
> > - struct rte_mbuf *elt = (*txq->elts)[elts_free & elts_m];
> > - struct rte_mbuf *elt_next =
> > - (*txq->elts)[(elts_free + 1) & elts_m];
> > -
> > + m = rte_pktmbuf_prefree_seg((*txq->elts)[elts_free++ & elts_m]);
> > + if (likely(m != NULL)) {
> > + if (blk_n) {
> > + if (likely(m->pool == free[0]->pool)) {
> > + free[blk_n++] = m;
> > + } else {
> > + rte_mempool_put_bulk(
> > + free[0]->pool,
> > + (void *)free,
> > + blk_n);
>
> The indentation is strange here, free[0] should be on the same line as
> rte_mempool_put_bulk.
>
> > + free[0] = m;
> > + blk_n = 1;
> > + }
> > + } else {
> > + free[0] = m;
> > + blk_n = 1;
> > + }
> > + }
>
> This loop could be smaller, blk_n can only be equal to 0 in the first
> iteration, otherwise is >= 1.
> The first if statement can be merged with the second one:
>
> if (likely(m != NULL)) {
> if (likely(blk_n && m->pool == free[0]->pool)) {
This condition is a wrong also, it should be !blk_n || (m->pool ...
Why don't you keep a pointer to the mpool (e.g. m->pool == pool)? It
seems to cost a little to deference two pointers to reach the pool's
one.
Thanks,
--
Nélio Laranjeiro
6WIND
