From: "Morten Brørup" <mb@smartsharesystems.com>
To: "Shijith Thotton" <sthotton@marvell.com>, <dev@dpdk.org>
Cc: <pbhagavatula@marvell.com>, <Honnappa.Nagarahalli@arm.com>,
<bruce.richardson@intel.com>, <jerinj@marvell.com>,
<olivier.matz@6wind.com>, <stephen@networkplumber.org>,
<thomas@monjalon.net>
Subject: RE: [PATCH v1 2/4] mbuf: add second dynamic field member for VA only build
Date: Mon, 29 Aug 2022 20:32:20 +0200 [thread overview]
Message-ID: <98CBD80474FA8B44BF855DF32C47DC35D872D1@smartserver.smartshare.dk> (raw)
In-Reply-To: <20220829151626.2101336-3-sthotton@marvell.com>
> From: Shijith Thotton [mailto:sthotton@marvell.com]
> Sent: Monday, 29 August 2022 17.16
>
> mbuf physical address field is not used in builds which only uses VA.
> It is used to expand the dynamic field area.
>
> Signed-off-by: Shijith Thotton <sthotton@marvell.com>
> ---
> lib/mbuf/rte_mbuf_core.h | 26 +++++++++++++++++---------
> lib/mbuf/rte_mbuf_dyn.c | 2 ++
> 2 files changed, 19 insertions(+), 9 deletions(-)
>
> diff --git a/lib/mbuf/rte_mbuf_core.h b/lib/mbuf/rte_mbuf_core.h
> index 81cb07c2e4..98ce62fd6a 100644
> --- a/lib/mbuf/rte_mbuf_core.h
> +++ b/lib/mbuf/rte_mbuf_core.h
> @@ -579,15 +579,23 @@ struct rte_mbuf {
> RTE_MARKER cacheline0;
>
> void *buf_addr; /**< Virtual address of segment buffer.
> */
> - /**
> - * Physical address of segment buffer.
> - * This field is invalid if the build is configured to use only
> - * virtual address as IOVA (i.e. RTE_IOVA_AS_VA is defined).
> - * Force alignment to 8-bytes, so as to ensure we have the exact
> - * same mbuf cacheline0 layout for 32-bit and 64-bit. This makes
> - * working on vector drivers easier.
> - */
> - rte_iova_t buf_iova __rte_aligned(sizeof(rte_iova_t));
> + RTE_STD_C11
> + union {
> + /**
> + * Physical address of segment buffer.
> + * This field is invalid if the build is configured to use
> only
> + * virtual address as IOVA (i.e. RTE_IOVA_AS_VA is
> defined).
> + * Force alignment to 8-bytes, so as to ensure we have the
> exact
> + * same mbuf cacheline0 layout for 32-bit and 64-bit. This
> makes
> + * working on vector drivers easier.
> + */
> + rte_iova_t buf_iova __rte_aligned(sizeof(rte_iova_t));
> + /**
> + * Reserved for dynamic field in builds where physical
> address
> + * field is invalid.
> + */
> + uint64_t dynfield2;
> + };
>
> /* next 8 bytes are initialised on RX descriptor rearm */
> RTE_MARKER64 rearm_data;
I know that the intention here is to keep the rte_mbuf structure intact, which will certainly improve the probability of getting this patch series into DPDK.
So, I will add a comment for the benefit of the other participants in the discussion:
With this patch, and in RTE_IOVA_AS_VA mode, it becomes possible to move m->next into the first cache line, so rte_pktmbuf_prefree_seg() does not have to touch the second cache line, thus potentially improving performance by eliminating one cache miss per freed packet segment. (I also recall someone mentioning that some PMDs set m->next on RX... If that is the case, a cache miss per packet might also be avoidable in those PMDs.)
Obviously, moving m->next to the first cache line is not related to this patch series, but would belong in a completely different patch.
next prev parent reply other threads:[~2022-08-29 18:32 UTC|newest]
Thread overview: 88+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-30 16:25 [PATCH] mbuf: add mbuf physical address field to dynamic field Shijith Thotton
2022-06-30 16:45 ` Stephen Hemminger
2022-07-01 12:16 ` Shijith Thotton
2022-07-01 12:24 ` Shijith Thotton
2022-07-03 7:31 ` Morten Brørup
2022-07-04 14:00 ` Bruce Richardson
2022-08-03 15:34 ` [EXT] " Shijith Thotton
2022-08-29 15:16 ` [PATCH v1 0/4] mbuf dynamic field expansion Shijith Thotton
2022-09-07 13:43 ` [PATCH v2 0/5] " Shijith Thotton
2022-09-21 9:43 ` David Marchand
2022-09-21 14:01 ` [EXT] " Shijith Thotton
2022-09-21 13:56 ` [PATCH v3 " Shijith Thotton
2022-09-21 13:56 ` [PATCH v3 1/5] build: add meson option to configure IOVA mode as VA Shijith Thotton
2022-09-28 12:52 ` Olivier Matz
2022-09-29 5:48 ` [EXT] " Shijith Thotton
2022-09-21 13:56 ` [PATCH v3 2/5] mbuf: add second dynamic field member for VA only build Shijith Thotton
2022-09-28 7:24 ` Thomas Monjalon
2022-09-28 12:52 ` Olivier Matz
2022-09-28 19:33 ` Thomas Monjalon
2022-09-28 19:48 ` Stephen Hemminger
2022-09-29 6:13 ` [EXT] " Shijith Thotton
2022-09-28 12:52 ` Olivier Matz
2022-09-21 13:56 ` [PATCH v3 3/5] lib: move mbuf next pointer to first cache line Shijith Thotton
2022-09-21 14:07 ` Morten Brørup
2022-09-28 12:52 ` Olivier Matz
2022-09-29 6:14 ` [EXT] " Shijith Thotton
2022-09-21 13:56 ` [PATCH v3 4/5] drivers: mark Marvell cnxk PMDs work with IOVA as VA Shijith Thotton
2022-09-28 12:53 ` Olivier Matz
2022-09-29 6:19 ` [EXT] " Shijith Thotton
2022-09-29 7:44 ` Olivier Matz
2022-09-29 8:10 ` Shijith Thotton
2022-10-07 20:17 ` Olivier Matz
2022-10-07 20:22 ` [EXT] " Shijith Thotton
2022-09-21 13:56 ` [PATCH v3 5/5] drivers: mark software " Shijith Thotton
2022-09-28 5:41 ` [PATCH v3 0/5] mbuf dynamic field expansion Shijith Thotton
2022-09-28 12:52 ` Olivier Matz
2022-09-29 4:51 ` [EXT] " Shijith Thotton
2022-10-07 13:50 ` Thomas Monjalon
2022-10-07 19:35 ` [EXT] " Shijith Thotton
2022-10-07 19:30 ` [PATCH v4 0/7] " Shijith Thotton
2022-10-07 19:30 ` [PATCH v4 1/7] mbuf: add API to get and set mbuf physical address Shijith Thotton
2022-10-07 20:16 ` Olivier Matz
2022-10-07 20:20 ` [EXT] " Shijith Thotton
2022-10-07 19:30 ` [PATCH v4 2/7] test/dma: use API to get mbuf data " Shijith Thotton
2022-10-07 20:17 ` Olivier Matz
2022-10-07 19:30 ` [PATCH v4 3/7] build: add meson option to configure IOVA mode as PA Shijith Thotton
2022-10-07 19:30 ` [PATCH v4 4/7] mbuf: add second dynamic field member Shijith Thotton
2022-10-07 19:30 ` [PATCH v4 5/7] lib: move mbuf next pointer to first cache line Shijith Thotton
2022-10-07 19:30 ` [PATCH v4 6/7] drivers: mark cnxk PMDs work with IOVA as PA disabled Shijith Thotton
2022-10-07 19:30 ` [PATCH v4 7/7] drivers: mark software " Shijith Thotton
2022-10-07 20:19 ` [PATCH v4 0/7] mbuf dynamic field expansion Olivier Matz
2022-10-07 21:02 ` [PATCH v5 " Shijith Thotton
2022-10-07 21:02 ` [PATCH v5 1/7] mbuf: add API to get and set mbuf physical address Shijith Thotton
2022-10-07 21:20 ` Stephen Hemminger
2022-10-07 21:02 ` [PATCH v5 2/7] test/dma: use API to get mbuf data " Shijith Thotton
2022-10-07 21:02 ` [PATCH v5 3/7] build: add meson option to configure IOVA mode as PA Shijith Thotton
2022-10-07 21:02 ` [PATCH v5 4/7] mbuf: add second dynamic field member Shijith Thotton
2022-10-07 21:02 ` [PATCH v5 5/7] lib: move mbuf next pointer to first cache line Shijith Thotton
2022-10-07 21:22 ` Stephen Hemminger
2022-10-07 21:30 ` [EXT] " Shijith Thotton
2022-10-07 21:02 ` [PATCH v5 6/7] drivers: mark cnxk PMDs work with IOVA as PA disabled Shijith Thotton
2022-10-07 21:02 ` [PATCH v5 7/7] drivers: mark software " Shijith Thotton
2022-10-09 9:34 ` [PATCH v5 0/7] mbuf dynamic field expansion Thomas Monjalon
2022-09-07 13:43 ` [PATCH v2 1/5] build: add meson option to configure IOVA mode as VA Shijith Thotton
2022-09-07 15:31 ` Stephen Hemminger
2022-09-07 15:38 ` Bruce Richardson
2022-09-07 21:33 ` Morten Brørup
2022-09-07 13:43 ` [PATCH v2 2/5] mbuf: add second dynamic field member for VA only build Shijith Thotton
2022-09-07 13:43 ` [PATCH v2 3/5] lib: move mbuf next pointer to first cache line Shijith Thotton
2022-09-07 13:43 ` [PATCH v2 4/5] drivers: mark Marvell cnxk PMDs work with IOVA as VA Shijith Thotton
2022-09-07 13:43 ` [PATCH v2 5/5] drivers: mark software " Shijith Thotton
2022-08-29 15:16 ` [PATCH v1 1/4] build: add meson option to configure IOVA mode " Shijith Thotton
2022-08-29 18:18 ` Morten Brørup
2022-08-30 8:32 ` Bruce Richardson
2022-08-29 15:16 ` [PATCH v1 2/4] mbuf: add second dynamic field member for VA only build Shijith Thotton
2022-08-29 18:32 ` Morten Brørup [this message]
2022-08-30 8:35 ` Bruce Richardson
2022-08-30 8:41 ` [EXT] " Pavan Nikhilesh Bhagavatula
2022-08-30 13:22 ` Honnappa Nagarahalli
2022-09-07 13:55 ` Shijith Thotton
2022-08-29 15:16 ` [PATCH v1 3/4] drivers: mark Marvell cnxk PMDs work with IOVA as VA Shijith Thotton
2022-08-29 15:16 ` [PATCH v1 4/4] drivers: mark software " Shijith Thotton
2022-08-30 13:07 ` [PATCH] mbuf: add mbuf physical address field to dynamic field Ferruh Yigit
2022-09-12 13:19 ` [EXT] " Shijith Thotton
2022-06-30 16:55 ` Bruce Richardson
2022-07-01 9:48 ` Olivier Matz
2022-07-01 11:53 ` Slava Ovsiienko
2022-07-01 12:01 ` [EXT] " Shijith Thotton
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