[PATCH 5/9] mbuf: make rearm data address naturally aligned
From: Olivier Matz <hidden>
Date: 2017-03-08 09:42:23
Subsystem:
library code, networking drivers, the rest · Maintainers:
Andrew Morton, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
From: Jerin Jacob <redacted> To avoid multiple stores on fast path, Ethernet drivers aggregate the writes to data_off, refcnt, nb_segs and port to an uint64_t data and write the data in one shot with uint64_t* at &mbuf->rearm_data address. Some of the non-IA platforms have store operation overhead if the store address is not naturally aligned.This patch fixes the performance issue on those targets. Signed-off-by: Jerin Jacob <redacted> Signed-off-by: Olivier Matz <redacted> --- drivers/net/fm10k/fm10k_rxtx_vec.c | 3 --- drivers/net/i40e/i40e_rxtx_vec_sse.c | 5 +---- drivers/net/ixgbe/ixgbe_rxtx_vec_neon.c | 3 --- drivers/net/ixgbe/ixgbe_rxtx_vec_sse.c | 3 --- lib/librte_eal/linuxapp/eal/include/exec-env/rte_kni_common.h | 3 +-- lib/librte_mbuf/rte_mbuf.h | 6 +++--- 6 files changed, 5 insertions(+), 18 deletions(-)
diff --git a/drivers/net/fm10k/fm10k_rxtx_vec.c b/drivers/net/fm10k/fm10k_rxtx_vec.c
index 825e3c1..61a65e9 100644
--- a/drivers/net/fm10k/fm10k_rxtx_vec.c
+++ b/drivers/net/fm10k/fm10k_rxtx_vec.c@@ -324,9 +324,6 @@ fm10k_rxq_rearm(struct fm10k_rx_queue *rxq) /* Flush mbuf with pkt template. * Data to be rearmed is 6 bytes long. - * Though, RX will overwrite ol_flags that are coming next - * anyway. So overwrite whole 8 bytes with one load: - * 6 bytes of rearm_data plus first 2 bytes of ol_flags. */ p0 = (uintptr_t)&mb0->rearm_data; *(uint64_t *)p0 = rxq->mbuf_initializer;
diff --git a/drivers/net/i40e/i40e_rxtx_vec_sse.c b/drivers/net/i40e/i40e_rxtx_vec_sse.c
index 2f861fd..e17235a 100644
--- a/drivers/net/i40e/i40e_rxtx_vec_sse.c
+++ b/drivers/net/i40e/i40e_rxtx_vec_sse.c@@ -87,11 +87,8 @@ i40e_rxq_rearm(struct i40e_rx_queue *rxq) mb0 = rxep[0].mbuf; mb1 = rxep[1].mbuf; - /* Flush mbuf with pkt template. + /* Flush mbuf with pkt template. * Data to be rearmed is 6 bytes long. - * Though, RX will overwrite ol_flags that are coming next - * anyway. So overwrite whole 8 bytes with one load: - * 6 bytes of rearm_data plus first 2 bytes of ol_flags. */ p0 = (uintptr_t)&mb0->rearm_data; *(uint64_t *)p0 = rxq->mbuf_initializer;
diff --git a/drivers/net/ixgbe/ixgbe_rxtx_vec_neon.c b/drivers/net/ixgbe/ixgbe_rxtx_vec_neon.c
index 2c04161..bc8924f 100644
--- a/drivers/net/ixgbe/ixgbe_rxtx_vec_neon.c
+++ b/drivers/net/ixgbe/ixgbe_rxtx_vec_neon.c@@ -85,9 +85,6 @@ ixgbe_rxq_rearm(struct ixgbe_rx_queue *rxq) /* * Flush mbuf with pkt template. * Data to be rearmed is 6 bytes long. - * Though, RX will overwrite ol_flags that are coming next - * anyway. So overwrite whole 8 bytes with one load: - * 6 bytes of rearm_data plus first 2 bytes of ol_flags. */ vst1_u8((uint8_t *)&mb0->rearm_data, p); paddr = mb0->buf_physaddr + RTE_PKTMBUF_HEADROOM;
diff --git a/drivers/net/ixgbe/ixgbe_rxtx_vec_sse.c b/drivers/net/ixgbe/ixgbe_rxtx_vec_sse.c
index 65c5da3..62afe31 100644
--- a/drivers/net/ixgbe/ixgbe_rxtx_vec_sse.c
+++ b/drivers/net/ixgbe/ixgbe_rxtx_vec_sse.c@@ -90,9 +90,6 @@ ixgbe_rxq_rearm(struct ixgbe_rx_queue *rxq) /* * Flush mbuf with pkt template. * Data to be rearmed is 6 bytes long. - * Though, RX will overwrite ol_flags that are coming next - * anyway. So overwrite whole 8 bytes with one load: - * 6 bytes of rearm_data plus first 2 bytes of ol_flags. */ p0 = (uintptr_t)&mb0->rearm_data; *(uint64_t *)p0 = rxq->mbuf_initializer;
diff --git a/lib/librte_eal/linuxapp/eal/include/exec-env/rte_kni_common.h b/lib/librte_eal/linuxapp/eal/include/exec-env/rte_kni_common.h
index 09713b0..f24f79f 100644
--- a/lib/librte_eal/linuxapp/eal/include/exec-env/rte_kni_common.h
+++ b/lib/librte_eal/linuxapp/eal/include/exec-env/rte_kni_common.h@@ -116,11 +116,10 @@ struct rte_kni_fifo { struct rte_kni_mbuf { void *buf_addr __attribute__((__aligned__(RTE_CACHE_LINE_SIZE))); uint64_t buf_physaddr; - char pad0[2]; uint16_t data_off; /**< Start address of data in segment buffer. */ char pad1[2]; uint8_t nb_segs; /**< Number of segments. */ - char pad4[1]; + char pad4[3]; uint64_t ol_flags; /**< Offload features. */ char pad2[4]; uint32_t pkt_len; /**< Total pkt len: sum of all segment data_len. */
diff --git a/lib/librte_mbuf/rte_mbuf.h b/lib/librte_mbuf/rte_mbuf.h
index b4fe786..4dc9a20 100644
--- a/lib/librte_mbuf/rte_mbuf.h
+++ b/lib/librte_mbuf/rte_mbuf.h@@ -393,10 +393,8 @@ struct rte_mbuf { void *buf_addr; /**< Virtual address of segment buffer. */ phys_addr_t buf_physaddr; /**< Physical address of segment buffer. */ - uint16_t buf_len; /**< Length of segment buffer. */ - /* next 6 bytes are initialised on RX descriptor rearm */ - MARKER8 rearm_data; + MARKER64 rearm_data; uint16_t data_off; /**
@@ -414,6 +412,7 @@ struct rte_mbuf { }; uint8_t nb_segs; /**< Number of segments. */ uint8_t port; /**< Input port. */ + uint16_t pad; /**< 2B pad for naturally aligned ol_flags */ uint64_t ol_flags; /**< Offload features. */
@@ -474,6 +473,7 @@ struct rte_mbuf { /** Outer VLAN TCI (CPU order), valid if PKT_RX_QINQ_STRIPPED is set. */ uint16_t vlan_tci_outer; + uint16_t buf_len; /**< Length of segment buffer. */ /* second cache line - fields only used in slow path or on TX */ MARKER cacheline1 __rte_cache_min_aligned;
--
2.8.1