[dpdk-dev] [PATCH v2 5/8] mbuf: make rearm data address naturally aligned
Olivier Matz
olivier.matz at 6wind.com
Tue Apr 4 18:28:04 CEST 2017
From: Jerin Jacob <jerin.jacob at caviumnetworks.com>
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 <jerin.jacob at caviumnetworks.com>
Signed-off-by: Olivier Matz <olivier.matz at 6wind.com>
---
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 825e3c125..61a65e9bf 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 2f861fde8..e17235abf 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 2c0416179..bc8924fbb 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 65c5da3c7..62afe3100 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 09713b0c2..f24f79fa2 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 1efebec7c..4ef27f92a 100644
--- a/lib/librte_mbuf/rte_mbuf.h
+++ b/lib/librte_mbuf/rte_mbuf.h
@@ -400,10 +400,8 @@ 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;
/**
@@ -421,6 +419,7 @@ 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. */
@@ -481,6 +480,7 @@ 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;
--
2.11.0
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