When calculating the mbuf data_room_size (i.e. the size of actual packet data that an mbuf can accomodate), it is possible to simply use the value calculated by dpdk_buf_size() as a parameter to rte_pktmbuf_pool_create(). This simplifies mbuf sizing considerably. This patch removes the related size conversions and macros, which are no longer needed.
The benefits of this approach are threefold: - the mbuf sizing code is much simpler, and more readable. - mbuf size will always be cache-aligned [1], satisfying that requirement of specific PMDs (vNIC thunderx, for example). - the maximum amount of data that each mbuf contains may now be calculated as mbuf->buf_len - mbuf->data_off. This is important in the case of multi-segment jumbo frames. [1] (this is true since mbuf size is now always a multiple of 1024, + 128B RTE_PKTMBUF_HEADROOM + 704B dp_packet). Fixes: 4be4d22 ("netdev-dpdk: clean up mbuf initialization") Fixes: 31b88c9 ("netdev-dpdk: round up mbuf_size to cache_line_size") Signed-off-by: Mark Kavanagh <mark.b.kavan...@intel.com> --- lib/netdev-dpdk.c | 22 ++++++++-------------- 1 file changed, 8 insertions(+), 14 deletions(-) diff --git a/lib/netdev-dpdk.c b/lib/netdev-dpdk.c index 8906423..c5eb851 100644 --- a/lib/netdev-dpdk.c +++ b/lib/netdev-dpdk.c @@ -81,12 +81,6 @@ static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 20); + (2 * VLAN_HEADER_LEN)) #define MTU_TO_FRAME_LEN(mtu) ((mtu) + ETHER_HDR_LEN + ETHER_CRC_LEN) #define MTU_TO_MAX_FRAME_LEN(mtu) ((mtu) + ETHER_HDR_MAX_LEN) -#define FRAME_LEN_TO_MTU(frame_len) ((frame_len) \ - - ETHER_HDR_LEN - ETHER_CRC_LEN) -#define MBUF_SIZE(mtu) ROUND_UP((MTU_TO_MAX_FRAME_LEN(mtu) \ - + sizeof(struct dp_packet) \ - + RTE_PKTMBUF_HEADROOM), \ - RTE_CACHE_LINE_SIZE) #define NETDEV_DPDK_MBUF_ALIGN 1024 #define NETDEV_DPDK_MAX_PKT_LEN 9728 @@ -447,7 +441,7 @@ is_dpdk_class(const struct netdev_class *class) * behaviour, which reduces performance. To prevent this, use a buffer size * that is closest to 'mtu', but which satisfies the aforementioned criteria. */ -static uint32_t +static uint16_t dpdk_buf_size(int mtu) { return ROUND_UP((MTU_TO_MAX_FRAME_LEN(mtu) + RTE_PKTMBUF_HEADROOM), @@ -486,7 +480,7 @@ ovs_rte_pktmbuf_init(struct rte_mempool *mp OVS_UNUSED, * - a new mempool was just created; * - a matching mempool already exists. */ static struct rte_mempool * -dpdk_mp_create(struct netdev_dpdk *dev, int mtu) +dpdk_mp_create(struct netdev_dpdk *dev, uint16_t frame_len) { char mp_name[RTE_MEMPOOL_NAMESIZE]; const char *netdev_name = netdev_get_name(&dev->up); @@ -513,12 +507,12 @@ dpdk_mp_create(struct netdev_dpdk *dev, int mtu) * longer than RTE_MEMPOOL_NAMESIZE. */ int ret = snprintf(mp_name, RTE_MEMPOOL_NAMESIZE, "ovs%08x%02d%05d%07u", - hash, socket_id, mtu, n_mbufs); + hash, socket_id, frame_len, n_mbufs); if (ret < 0 || ret >= RTE_MEMPOOL_NAMESIZE) { VLOG_DBG("snprintf returned %d. " "Failed to generate a mempool name for \"%s\". " - "Hash:0x%x, socket_id: %d, mtu:%d, mbufs:%u.", - ret, netdev_name, hash, socket_id, mtu, n_mbufs); + "Hash:0x%x, socket_id: %d, frame length:%d, mbufs:%u.", + ret, netdev_name, hash, socket_id, frame_len, n_mbufs); break; } @@ -529,7 +523,7 @@ dpdk_mp_create(struct netdev_dpdk *dev, int mtu) mp = rte_pktmbuf_pool_create(mp_name, n_mbufs, MP_CACHE_SZ, sizeof (struct dp_packet) - sizeof (struct rte_mbuf), - MBUF_SIZE(mtu) - sizeof(struct dp_packet), socket_id); + frame_len + RTE_PKTMBUF_HEADROOM, socket_id); if (mp) { VLOG_DBG("Allocated \"%s\" mempool with %u mbufs", @@ -582,11 +576,11 @@ static int netdev_dpdk_mempool_configure(struct netdev_dpdk *dev) OVS_REQUIRES(dev->mutex) { - uint32_t buf_size = dpdk_buf_size(dev->requested_mtu); + uint16_t buf_size = dpdk_buf_size(dev->requested_mtu); struct rte_mempool *mp; int ret = 0; - mp = dpdk_mp_create(dev, FRAME_LEN_TO_MTU(buf_size)); + mp = dpdk_mp_create(dev, buf_size); if (!mp) { VLOG_ERR("Failed to create memory pool for netdev " "%s, with MTU %d on socket %d: %s\n", -- 1.9.3 _______________________________________________ dev mailing list d...@openvswitch.org https://mail.openvswitch.org/mailman/listinfo/ovs-dev