[dpdk-dev] [PATCH RFC 06/11] mbuf: replace data pointer by an offset
Thomas Monjalon
thomas.monjalon at 6wind.com
Mon May 12 16:12:50 CEST 2014
Hi Olivier,
2014-05-09 16:50, Olivier Matz:
> The mbuf structure already contains a pointer to the beginning of the
> buffer (m->buf_addr). It is not needed to use 8 bytes again to store
> another pointer to the beginning of the data.
>
> Using a 16 bits unsigned integer is enough as we know that a mbuf is
> never longer than 64KB. We gain 6 bytes in the structure thanks to
> this modification.
>
> Signed-off-by: Olivier Matz <olivier.matz at 6wind.com>
[...]
> --- a/lib/librte_mbuf/rte_mbuf.h
> +++ b/lib/librte_mbuf/rte_mbuf.h
> @@ -132,6 +132,13 @@ struct rte_mbuf {
> void *buf_addr; /**< Virtual address of segment buffer. */
> uint64_t buf_physaddr:48; /**< Physical address of segment buffer. */
> uint64_t buf_len:16; /**< Length of segment buffer. */
> +
> + /* valid for any segment */
> + struct rte_mbuf *next; /**< Next segment of scattered packet. */
> + 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
> /**
> * 16-bit Reference counter.
> @@ -142,36 +149,30 @@ struct rte_mbuf {
> * config option.
> */
> union {
> - rte_atomic16_t refcnt_atomic; /**< Atomically accessed refcnt */
> - uint16_t refcnt; /**< Non-atomically accessed refcnt
*/
> + rte_atomic16_t refcnt_atomic; /**< Atomically accessed refcnt */
> + uint16_t refcnt; /**< Non-atomically accessed refcnt */
> };
> #else
> - uint16_t refcnt_reserved; /**< Do not use this field */
> + uint16_t refcnt_reserved; /**< Do not use this field */
> #endif
>
> - uint16_t ol_flags; /**< Offload features. */
> - uint32_t reserved; /**< Unused field. Required for padding.
*/
> -
> - /* valid for any segment */
> - struct rte_mbuf *next; /**< Next segment of scattered packet. */
> - void* data; /**< Start address of data in segment buffer. */
> - uint16_t data_len; /**< Amount of data in segment buffer. */
> -
> /* these fields are valid for first segment only */
> - uint8_t nb_segs; /**< Number of segments. */
> - uint8_t in_port; /**< Input port. */
> - uint32_t pkt_len; /**< Total pkt len: sum of all segment data_len.
> */ + uint8_t nb_segs; /**< Number of segments. */
> + uint8_t in_port; /**< Input port. */
> + uint16_t ol_flags; /**< Offload features. */
> + uint16_t reserved; /**< Unused field. Required for padding. */
>
> /* offload features, valid for first segment only */
> union rte_vlan_macip vlan_macip;
> union {
> - uint32_t rss; /**< RSS hash result if RSS enabled */
> + uint32_t rss; /**< RSS hash result if RSS enabled */
> struct {
> uint16_t hash;
> uint16_t id;
> - } fdir; /**< Filter identifier if FDIR enabled */
> - uint32_t sched; /**< Hierarchical scheduler */
> - } hash; /**< hash information */
> + } fdir; /**< Filter identifier if FDIR enabled */
> + uint32_t sched; /**< Hierarchical scheduler */
> + } hash; /**< hash information */
> + uint64_t reserved2; /**< Unused field. Required for padding. */
> } __rte_cache_aligned;
There are some cosmetic changes mixed with real changes.
It make hard to read them.
Please split this patch.
--
Thomas
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