net/sfc: free mbufs in bulks on EF10 native Tx reap

Signed-off-by: Ivan Malov <ivan.malov@oktetlabs.ru>
Signed-off-by: Andrew Rybchenko <arybchenko@solarflare.com>

diff --git a/drivers/net/sfc/Makefile b/drivers/net/sfc/Makefile
index 57aa963..0adb786 100644 (file)
--- a/drivers/net/sfc/Makefile
+++ b/drivers/net/sfc/Makefile
@@ -65,6 +65,9 @@ CFLAGS += -Wbad-function-cast
 CFLAGS_BASE_DRIVER += -Wno-empty-body
 else ifeq ($(CONFIG_RTE_TOOLCHAIN_ICC),y)
 CFLAGS_BASE_DRIVER += -Wno-unused-but-set-variable
+# Suppress ICC false positive warning on 'bulk' may be used before its
+# value is set
+CFLAGS_sfc_ef10_tx.o += -wd3656
 endif
 
 #

diff --git a/drivers/net/sfc/sfc_ef10_tx.c b/drivers/net/sfc/sfc_ef10_tx.c
index 182fc23..5127a7a 100644 (file)
--- a/drivers/net/sfc/sfc_ef10_tx.c
+++ b/drivers/net/sfc/sfc_ef10_tx.c
@@ -158,17 +158,35 @@ sfc_ef10_tx_reap(struct sfc_ef10_txq *txq)
        pending += sfc_ef10_tx_process_events(txq);
 
        if (pending != completed) {
+               struct rte_mbuf *bulk[SFC_TX_REAP_BULK_SIZE];
+               unsigned int nb = 0;
+
                do {
                        struct sfc_ef10_tx_sw_desc *txd;
+                       struct rte_mbuf *m;
 
                        txd = &txq->sw_ring[completed & ptr_mask];
+                       if (txd->mbuf == NULL)
+                               continue;
 
-                       if (txd->mbuf != NULL) {
-                               rte_pktmbuf_free(txd->mbuf);
-                               txd->mbuf = NULL;
+                       m = rte_pktmbuf_prefree_seg(txd->mbuf);
+                       txd->mbuf = NULL;
+                       if (m == NULL)
+                               continue;
+
+                       if ((nb == RTE_DIM(bulk)) ||
+                           ((nb != 0) && (m->pool != bulk[0]->pool))) {
+                               rte_mempool_put_bulk(bulk[0]->pool,
+                                                    (void *)bulk, nb);
+                               nb = 0;
                        }
+
+                       bulk[nb++] = m;
                } while (++completed != pending);
 
+               if (nb != 0)
+                       rte_mempool_put_bulk(bulk[0]->pool, (void *)bulk, nb);
+
                txq->completed = completed;
        }
 
@@ -325,6 +343,7 @@ sfc_ef10_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts, uint16_t nb_pkts)
                do {
                        phys_addr_t seg_addr = rte_mbuf_data_dma_addr(m_seg);
                        unsigned int seg_len = rte_pktmbuf_data_len(m_seg);
+                       unsigned int id = added & ptr_mask;
 
                        SFC_ASSERT(seg_len <= SFC_EF10_TX_DMA_DESC_LEN_MAX);
 
@@ -332,15 +351,30 @@ sfc_ef10_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts, uint16_t nb_pkts)
 
                        sfc_ef10_tx_qdesc_dma_create(seg_addr,
                                seg_len, (pkt_len == 0),
-                               &txq->txq_hw_ring[added & ptr_mask]);
+                               &txq->txq_hw_ring[id]);
+
+                       /*
+                        * rte_pktmbuf_free() is commonly used in DPDK for
+                        * recycling packets - the function checks every
+                        * segment's reference counter and returns the
+                        * buffer to its pool whenever possible;
+                        * nevertheless, freeing mbuf segments one by one
+                        * may entail some performance decline;
+                        * from this point, sfc_efx_tx_reap() does the same job
+                        * on its own and frees buffers in bulks (all mbufs
+                        * within a bulk belong to the same pool);
+                        * from this perspective, individual segment pointers
+                        * must be associated with the corresponding SW
+                        * descriptors independently so that only one loop
+                        * is sufficient on reap to inspect all the buffers
+                        */
+                       txq->sw_ring[id].mbuf = m_seg;
+
                        ++added;
 
                } while ((m_seg = m_seg->next) != 0);
 
                dma_desc_space -= (added - pkt_start);
-
-               /* Assign mbuf to the last used desc */
-               txq->sw_ring[(added - 1) & ptr_mask].mbuf = *pktp;
        }
 
        if (likely(added != txq->added)) {

diff --git a/drivers/net/sfc/sfc_tweak.h b/drivers/net/sfc/sfc_tweak.h
index 4ef7fc8..fd2f75c 100644 (file)
--- a/drivers/net/sfc/sfc_tweak.h
+++ b/drivers/net/sfc/sfc_tweak.h
@@ -53,4 +53,7 @@
 /** Default free threshold follows recommendations from DPDK documentation */
 #define SFC_TX_DEFAULT_FREE_THRESH     32
 
+/** Number of mbufs to be freed in bulk in a single call */
+#define SFC_TX_REAP_BULK_SIZE          32
+
 #endif /* _SFC_TWEAK_H_ */