Using memset to initialize struct odp_packet_hdr_t contents
to 0 has a significant overhead. Instead, initialize only
the required members of the struct.

Signed-off-by: Matias Elo <[email protected]>
---
 platform/linux-generic/include/odp_packet_internal.h | 13 +++++++++----
 platform/linux-generic/odp_packet.c                  | 18 ++++++------------
 2 files changed, 15 insertions(+), 16 deletions(-)

diff --git a/platform/linux-generic/include/odp_packet_internal.h 
b/platform/linux-generic/include/odp_packet_internal.h
index 1306b05..c87bc9f 100644
--- a/platform/linux-generic/include/odp_packet_internal.h
+++ b/platform/linux-generic/include/odp_packet_internal.h
@@ -4,7 +4,6 @@
  * SPDX-License-Identifier:     BSD-3-Clause
  */
 
-
 /**
  * @file
  *
@@ -129,11 +128,16 @@ ODP_STATIC_ASSERT(sizeof(output_flags_t) == 
sizeof(uint32_t),
 
 /**
  * Internal Packet header
+ *
+ * To optimize fast path performance this struct is not initialized to zero in
+ * packet_init(). Because of this any new fields added must be reviewed for
+ * initialization requirements.
  */
 typedef struct {
        /* common buffer header */
        odp_buffer_hdr_t buf_hdr;
 
+       /* Following members are initialized by packet_init() */
        input_flags_t  input_flags;
        error_flags_t  error_flags;
        output_flags_t output_flags;
@@ -142,15 +146,16 @@ typedef struct {
        uint32_t l3_offset; /**< offset to L3 hdr, e.g. IPv4, IPv6 */
        uint32_t l4_offset; /**< offset to L4 hdr (TCP, UDP, SCTP, also ICMP) */
 
-       uint32_t l3_len;         /**< Layer 3 length */
-       uint32_t l4_len;         /**< Layer 4 length */
-
        uint32_t frame_len;
        uint32_t headroom;
        uint32_t tailroom;
 
        odp_pktio_t input;
 
+       /* Members below are not initialized by packet_init() */
+       uint32_t l3_len;         /**< Layer 3 length */
+       uint32_t l4_len;         /**< Layer 4 length */
+
        uint32_t flow_hash;      /**< Flow hash value */
        odp_time_t timestamp;    /**< Timestamp value */
 
diff --git a/platform/linux-generic/odp_packet.c 
b/platform/linux-generic/odp_packet.c
index 4f523c9..8dde404 100644
--- a/platform/linux-generic/odp_packet.c
+++ b/platform/linux-generic/odp_packet.c
@@ -49,19 +49,11 @@ void packet_parse_reset(odp_packet_hdr_t *pkt_hdr)
 static void packet_init(pool_entry_t *pool, odp_packet_hdr_t *pkt_hdr,
                        size_t size, int parse)
 {
-       /*
-       * Reset parser metadata.  Note that we clear via memset to make
-       * this routine indepenent of any additional adds to packet metadata.
-       */
-       const size_t start_offset = ODP_FIELD_SIZEOF(odp_packet_hdr_t, buf_hdr);
-       uint8_t *start;
-       size_t len;
+       pkt_hdr->input_flags.all  = 0;
+       pkt_hdr->output_flags.all = 0;
+       pkt_hdr->error_flags.all  = 0;
 
-       start = (uint8_t *)pkt_hdr + start_offset;
-       len = sizeof(odp_packet_hdr_t) - start_offset;
-       memset(start, 0, len);
-
-       /* Set metadata items that initialize to non-zero values */
+       pkt_hdr->l2_offset = 0;
        pkt_hdr->l3_offset = ODP_PACKET_OFFSET_INVALID;
        pkt_hdr->l4_offset = ODP_PACKET_OFFSET_INVALID;
 
@@ -79,6 +71,8 @@ static void packet_init(pool_entry_t *pool, odp_packet_hdr_t 
*pkt_hdr,
        pkt_hdr->tailroom  =
                (pool->s.seg_size * pkt_hdr->buf_hdr.segcount) -
                (pool->s.headroom + size);
+
+       pkt_hdr->input = ODP_PKTIO_INVALID;
 }
 
 odp_packet_t packet_alloc(odp_pool_t pool_hdl, uint32_t len, int parse)
-- 
1.9.1

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