From: Andrew Rybchenko <arybchenko@solarflare.com>
To: Yongseok Koh <yskoh@mellanox.com>, <olivier.matz@6wind.com>,
<shahafs@mellanox.com>
Cc: <dev@dpdk.org>, <roszenrami@gmail.com>, <david.marchand@redhat.com>
Subject: Re: [dpdk-dev] [PATCH v3 1/2] mbuf: add function returning default buffer address
Date: Fri, 11 Jan 2019 11:14:22 +0300 [thread overview]
Message-ID: <2934bc73-98e6-643a-0d61-cf7804e1535d@solarflare.com> (raw)
In-Reply-To: <20190110183528.42503-1-yskoh@mellanox.com>
On 1/10/19 9:35 PM, Yongseok Koh wrote:
> This patch introduces two new functions - rte_mbuf_buf_addr() and
> rte_mbuf_data_addr_default().
>
> rte_mbuf_buf_addr() reutrns the default buffer address of given mbuf which
> comes after mbuf structure and private data.
>
> rte_mbuf_data_addr_default() returns the default address of mbuf data
> taking the headroom into account.
>
> Signed-off-by: Yongseok Koh <yskoh@mellanox.com>
> ---
>
> v3:
> * rename functions
>
> v2:
> * initial implementation
>
> lib/librte_mbuf/rte_mbuf.h | 43 ++++++++++++++++++++++++++++++++++++++++---
> 1 file changed, 40 insertions(+), 3 deletions(-)
>
> diff --git a/lib/librte_mbuf/rte_mbuf.h b/lib/librte_mbuf/rte_mbuf.h
> index bc562dc8a9..486566fc28 100644
> --- a/lib/librte_mbuf/rte_mbuf.h
> +++ b/lib/librte_mbuf/rte_mbuf.h
> @@ -788,8 +788,47 @@ rte_mbuf_from_indirect(struct rte_mbuf *mi)
> }
>
> /**
> + * Return the default buffer address of the mbuf.
> + *
> + * @param mb
> + * The pointer to the mbuf.
> + * @param mp
> + * The pointer to the mempool of the mbuf.
> + * @return
> + * The pointer of the mbuf buffer.
> + */
> +static inline char * __rte_experimental
> +rte_mbuf_buf_addr(struct rte_mbuf *mb, struct rte_mempool *mp)
struct rte_mbuf has pool member. So, I don't understand why mp
argument is required. I guess there is a reason, but it should be
explained in comments. I see motivation in rte_mbuf_to_baddr()
description, but rte_mbuf_buf_add() does not explain it.
Also right now the function name looks like simple get accessor for
buf_addr and I'd expect to seem one line implementation may be
with extra debug checks: return mb->buf_addr.
May be rte_mbuf_direct_buf_addr() ?
If so, similar below rte_mbuf_direct_data_addr_default().
> +{
> + char *buffer_addr;
> +
> + buffer_addr = (char *)mb + sizeof(*mb) + rte_pktmbuf_priv_size(mp);
> + return buffer_addr;
> +}
> +
> +
> +/**
> + * Return the default address of the beginning of the mbuf data.
> + *
> + * @param mb
> + * The pointer to the mbuf.
> + * @return
> + * The pointer of the beginning of the mbuf data.
> + */
> +static inline char * __rte_experimental
> +rte_mbuf_data_addr_default(struct rte_mbuf *mb)
> +{
> + return rte_mbuf_buf_addr(mb, mb->pool) + RTE_PKTMBUF_HEADROOM;
> +}
> +
> +/**
> * Return the buffer address embedded in the given mbuf.
> *
> + * Note that accessing mempool pointer of a mbuf is expensive because the
> + * pointer is stored in the 2nd cache line of mbuf. If mempool is known, it
> + * is better not to reference the mempool pointer in mbuf but calling
> + * rte_mbuf_buf_addr() would be more efficient.
> + *
> * @param md
> * The pointer to the mbuf.
> * @return
> @@ -798,9 +837,7 @@ rte_mbuf_from_indirect(struct rte_mbuf *mi)
> static inline char *
> rte_mbuf_to_baddr(struct rte_mbuf *md)
> {
> - char *buffer_addr;
> - buffer_addr = (char *)md + sizeof(*md) + rte_pktmbuf_priv_size(md->pool);
> - return buffer_addr;
> + return rte_mbuf_buf_addr(md, md->pool);
> }
>
> /**
next prev parent reply other threads:[~2019-01-11 8:14 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-09 8:54 [dpdk-dev] [PATCH] net/mlx5: fix instruction hotspot on replenishing Rx buffer Yongseok Koh
2019-01-09 9:38 ` David Marchand
2019-01-09 9:52 ` Olivier Matz
2019-01-09 9:56 ` Yongseok Koh
2019-01-09 10:05 ` David Marchand
2019-01-09 10:11 ` Yongseok Koh
2019-01-09 13:19 ` [dpdk-dev] [PATCH v2 1/2] mbuf: add function returning default buffer address Yongseok Koh
2019-01-09 13:19 ` [dpdk-dev] [PATCH v2 2/2] net/mlx5: fix instruction hotspot on replenishing Rx buffer Yongseok Koh
2019-01-09 13:46 ` [dpdk-dev] [PATCH v2 1/2] mbuf: add function returning default buffer address David Marchand
2019-01-10 1:39 ` Rami Rosen
2019-01-10 18:18 ` Yongseok Koh
2019-01-10 18:22 ` Yongseok Koh
2019-01-10 18:35 ` [dpdk-dev] [PATCH v3 " Yongseok Koh
2019-01-10 18:35 ` [dpdk-dev] [PATCH v3 2/2] net/mlx5: fix instruction hotspot on replenishing Rx buffer Yongseok Koh
2019-01-10 19:10 ` Shahaf Shuler
2019-01-11 8:14 ` Andrew Rybchenko [this message]
2019-01-11 11:03 ` [dpdk-dev] [PATCH v3 1/2] mbuf: add function returning default buffer address Yongseok Koh
2019-01-11 11:17 ` Andrew Rybchenko
2019-01-11 11:37 ` Yongseok Koh
2019-01-11 11:57 ` Bruce Richardson
2019-01-11 12:48 ` David Marchand
2019-01-14 15:51 ` Olivier Matz
2019-01-10 22:40 ` [dpdk-dev] [PATCH v4 " Yongseok Koh
2019-01-10 22:40 ` [dpdk-dev] [PATCH v4 2/2] net/mlx5: fix instruction hotspot on replenishing Rx buffer Yongseok Koh
2019-01-11 8:05 ` [dpdk-dev] [PATCH v4 1/2] mbuf: add function returning default buffer address Olivier Matz
2019-01-11 8:11 ` David Marchand
2019-01-11 8:32 ` David Marchand
2019-01-11 11:09 ` Yongseok Koh
2019-01-11 10:25 ` Thomas Monjalon
2019-01-14 21:16 ` [dpdk-dev] [PATCH v5 1/2] mbuf: add function returning " Yongseok Koh
2019-01-14 21:16 ` [dpdk-dev] [PATCH v5 2/2] net/mlx5: fix instruction hotspot on replenishing Rx buffer Yongseok Koh
2019-02-06 15:54 ` Kevin Traynor
2019-02-21 19:10 ` Kevin Traynor
2019-03-08 2:05 ` Yongseok Koh
2019-01-15 1:35 ` [dpdk-dev] [PATCH v5 1/2] mbuf: add function returning buffer address Thomas Monjalon
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