[dpdk-dev] [PATCH 1/2] net/ixgbe: eliminate mbuf write on rearm
Konstantin Ananyev
konstantin.ananyev at intel.com
Tue Apr 4 12:29:48 CEST 2017
With the mbuf rework, we now have 8 contiguous bytes to be rearmed in the
mbuf just before the 8-bytes of olflags. If we don't do the rearm write
inside the descriptor ring replenishment function, and delay it to
receiving the packet, we can do a single 16B write inside the RX function
to set both the rearm data, and the flags together.
Signed-off-by: Konstantin Ananyev <konstantin.ananyev at intel.com>
---
drivers/net/ixgbe/ixgbe_rxtx_vec_sse.c | 57 ++++++++++++++++++++++------------
1 file changed, 37 insertions(+), 20 deletions(-)
diff --git a/drivers/net/ixgbe/ixgbe_rxtx_vec_sse.c b/drivers/net/ixgbe/ixgbe_rxtx_vec_sse.c
index 62afe31..49536c1 100644
--- a/drivers/net/ixgbe/ixgbe_rxtx_vec_sse.c
+++ b/drivers/net/ixgbe/ixgbe_rxtx_vec_sse.c
@@ -82,19 +82,23 @@ ixgbe_rxq_rearm(struct ixgbe_rx_queue *rxq)
/* Initialize the mbufs in vector, process 2 mbufs in one loop */
for (i = 0; i < RTE_IXGBE_RXQ_REARM_THRESH; i += 2, rxep += 2) {
__m128i vaddr0, vaddr1;
- uintptr_t p0, p1;
mb0 = rxep[0].mbuf;
mb1 = rxep[1].mbuf;
- /*
- * Flush mbuf with pkt template.
- * Data to be rearmed is 6 bytes long.
- */
- p0 = (uintptr_t)&mb0->rearm_data;
- *(uint64_t *)p0 = rxq->mbuf_initializer;
- p1 = (uintptr_t)&mb1->rearm_data;
- *(uint64_t *)p1 = rxq->mbuf_initializer;
+#ifndef RTE_IXGBE_RX_OLFLAGS_ENABLE
+ {
+ uintptr_t p0, p1;
+ /*
+ * Flush mbuf with pkt template.
+ * Data to be rearmed is 6 bytes long.
+ */
+ p0 = (uintptr_t)&mb0->rearm_data;
+ *(uint64_t *)p0 = rxq->mbuf_initializer;
+ p1 = (uintptr_t)&mb1->rearm_data;
+ *(uint64_t *)p1 = rxq->mbuf_initializer;
+ }
+#endif
/* load buf_addr(lo 64bit) and buf_physaddr(hi 64bit) */
vaddr0 = _mm_loadu_si128((__m128i *)&(mb0->buf_addr));
@@ -139,14 +143,11 @@ ixgbe_rxq_rearm(struct ixgbe_rx_queue *rxq)
#ifdef RTE_IXGBE_RX_OLFLAGS_ENABLE
static inline void
-desc_to_olflags_v(__m128i descs[4], uint8_t vlan_flags,
+desc_to_olflags_v(__m128i descs[4], __m128i mbuf_init, uint8_t vlan_flags,
struct rte_mbuf **rx_pkts)
{
__m128i ptype0, ptype1, vtag0, vtag1, csum;
- union {
- uint16_t e[4];
- uint64_t dword;
- } vol;
+ __m128i rearm0, rearm1, rearm2, rearm3;
/* mask everything except rss type */
const __m128i rsstype_msk = _mm_set_epi16(
@@ -225,12 +226,25 @@ desc_to_olflags_v(__m128i descs[4], uint8_t vlan_flags,
vtag1 = _mm_or_si128(vtag0, vtag1);
vtag1 = _mm_or_si128(ptype0, vtag1);
- vol.dword = _mm_cvtsi128_si64(vtag1);
- rx_pkts[0]->ol_flags = vol.e[0];
- rx_pkts[1]->ol_flags = vol.e[1];
- rx_pkts[2]->ol_flags = vol.e[2];
- rx_pkts[3]->ol_flags = vol.e[3];
+ /*
+ * At this point, we have the 4 sets of flags in the low 64-bits
+ * of vtag1 (4x16).
+ * We want to extract these, and merge them with the mbuf init data
+ * so we can do a single 16-byte write to the mbuf to set the flags
+ * and all the other initialization fields. Extracting the
+ * appropriate flags means that we have to do a shift and blend for
+ * each mbuf before we do the write.
+ */
+ rearm0 = _mm_blend_epi16(mbuf_init, _mm_slli_si128(vtag1, 8), 0x10);
+ rearm1 = _mm_blend_epi16(mbuf_init, _mm_slli_si128(vtag1, 6), 0x10);
+ rearm2 = _mm_blend_epi16(mbuf_init, _mm_slli_si128(vtag1, 4), 0x10);
+ rearm3 = _mm_blend_epi16(mbuf_init, _mm_slli_si128(vtag1, 2), 0x10);
+
+ _mm_store_si128((__m128i *)&rx_pkts[0]->rearm_data, rearm0);
+ _mm_store_si128((__m128i *)&rx_pkts[1]->rearm_data, rearm1);
+ _mm_store_si128((__m128i *)&rx_pkts[2]->rearm_data, rearm2);
+ _mm_store_si128((__m128i *)&rx_pkts[3]->rearm_data, rearm3);
}
#else
#define desc_to_olflags_v(desc, vlan_flags, rx_pkts) do { \
@@ -265,6 +279,7 @@ _recv_raw_pkts_vec(struct ixgbe_rx_queue *rxq, struct rte_mbuf **rx_pkts,
0, 0 /* ignore pkt_type field */
);
__m128i dd_check, eop_check;
+ __m128i mbuf_init;
uint8_t vlan_flags;
/* nb_pkts shall be less equal than RTE_IXGBE_MAX_RX_BURST */
@@ -310,6 +325,8 @@ _recv_raw_pkts_vec(struct ixgbe_rx_queue *rxq, struct rte_mbuf **rx_pkts,
0xFF, 0xFF
);
+ mbuf_init = _mm_set_epi64x(0, rxq->mbuf_initializer);
+
/* Cache is empty -> need to scan the buffer rings, but first move
* the next 'n' mbufs into the cache
*/
@@ -382,7 +399,7 @@ _recv_raw_pkts_vec(struct ixgbe_rx_queue *rxq, struct rte_mbuf **rx_pkts,
sterr_tmp1 = _mm_unpackhi_epi32(descs[1], descs[0]);
/* set ol_flags with vlan packet type */
- desc_to_olflags_v(descs, vlan_flags, &rx_pkts[pos]);
+ desc_to_olflags_v(descs, mbuf_init, vlan_flags, &rx_pkts[pos]);
/* D.2 pkt 3,4 set in_port/nb_seg and remove crc */
pkt_mb4 = _mm_add_epi16(pkt_mb4, crc_adjust);
--
2.5.0
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