From 21dc08a9917336199b55d993b4829dffc9637cd1 Mon Sep 17 00:00:00 2001 From: Bruce Richardson Date: Thu, 11 Sep 2014 14:15:36 +0100 Subject: [PATCH] mbuf: reorder fields by time of use * Reorder the fields in the mbuf so that we have fields that are used together side-by-side in the structure. This means that we have a contiguous block of 8-bytes in the mbuf which are used to reset an mbuf of descriptor rearm, and a block of 16-bytes of data (excluding flags) which are set on RX from the received packet descriptor. * Use dummy fields as appropriate to ensure alignment or to reserve gaps for later field additions. * Place most items which are not used by fast-path RX separately at the end of the structure so they can later be moved to a separate cache line. [The l2/l3 length fields are not moved at this stage as doing so will cause overflow to the next cache line]. Signed-off-by: Bruce Richardson Acked-by: Olivier Matz --- .../eal/include/exec-env/rte_kni_common.h | 12 +++++---- lib/librte_mbuf/rte_mbuf.h | 25 +++++++++++-------- 2 files changed, 21 insertions(+), 16 deletions(-) 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 07908ac492..f2b502ce22 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 @@ -108,15 +108,17 @@ struct rte_kni_fifo { * Padding is necessary to assure the offsets of these fields */ struct rte_kni_mbuf { - void *pool; void *buf_addr; - char pad0[16]; - void *next; + char pad0[10]; uint16_t data_off; /**< Start address of data in segment buffer. */ + char pad1[4]; + uint16_t ol_flags; /**< Offload features. */ + char pad2[8]; uint16_t data_len; /**< Amount of data in segment buffer. */ uint32_t pkt_len; /**< Total pkt len: sum of all segment data_len. */ - char pad2[4]; - uint16_t ol_flags; /**< Offload features. */ + char pad3[8]; + void *pool; + void *next; } __attribute__((__aligned__(64))); /* diff --git a/lib/librte_mbuf/rte_mbuf.h b/lib/librte_mbuf/rte_mbuf.h index 71080e589a..413a5a13dc 100644 --- a/lib/librte_mbuf/rte_mbuf.h +++ b/lib/librte_mbuf/rte_mbuf.h @@ -115,16 +115,12 @@ extern "C" { * The generic rte_mbuf, containing a packet mbuf. */ struct rte_mbuf { - struct rte_mempool *pool; /**< Pool from which mbuf was allocated. */ 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. */ - /* valid for any segment */ - struct rte_mbuf *next; /**< Next segment of scattered packet. */ + /* next 8 bytes are initialised on RX descriptor rearm */ + uint16_t buf_len; /**< Length of segment buffer. */ uint16_t data_off; - uint16_t data_len; /**< Amount of data in segment buffer. */ - uint32_t pkt_len; /**< Total pkt len: sum of all segments. */ #ifdef RTE_MBUF_REFCNT /** @@ -142,14 +138,17 @@ struct rte_mbuf { #else uint16_t refcnt_reserved; /**< Do not use this field */ #endif - uint16_t reserved; /**< Unused field. Required for padding */ - uint16_t ol_flags; /**< Offload features. */ - - /* these fields are valid for first segment only */ uint8_t nb_segs; /**< Number of segments. */ uint8_t port; /**< Input port. */ - /* offload features, valid for first segment only */ + uint16_t ol_flags; /**< Offload features. */ + uint16_t reserved0; /**< Unused field. Required for padding */ + uint32_t reserved1; /**< Unused field. Required for padding */ + + /* remaining bytes are set on RX when pulling packet from descriptor */ + uint16_t reserved2; /**< Unused field. Required for padding */ + uint16_t data_len; /**< Amount of data in segment buffer. */ + uint32_t pkt_len; /**< Total pkt len: sum of all segments. */ union { uint16_t l2_l3_len; /**< combined l2/l3 lengths as single var */ struct { @@ -167,6 +166,10 @@ struct rte_mbuf { uint32_t sched; /**< Hierarchical scheduler */ } hash; /**< hash information */ + /* fields only used in slow path or on TX */ + struct rte_mempool *pool; /**< Pool from which mbuf was allocated. */ + struct rte_mbuf *next; /**< Next segment of scattered packet. */ + union { uint8_t metadata[0]; uint16_t metadata16[0]; -- 2.20.1