From: Shijith Thotton <sthotton@marvell.com>
To: "Bruce Richardson" <bruce.richardson@intel.com>,
"Morten Brørup" <mb@smartsharesystems.com>
Cc: "stephen@networkplumber.org" <stephen@networkplumber.org>,
"olivier.matz@6wind.com" <olivier.matz@6wind.com>,
"dev@dpdk.org" <dev@dpdk.org>,
Jerin Jacob Kollanukkaran <jerinj@marvell.com>,
"thomas@monjalon.net" <thomas@monjalon.net>,
Honnappa Nagarahalli <Honnappa.Nagarahalli@arm.com>
Subject: RE: [EXT] Re: [PATCH] mbuf: add mbuf physical address field to dynamic field
Date: Wed, 3 Aug 2022 15:34:08 +0000 [thread overview]
Message-ID: <PH0PR18MB4425D140694D972E19B6770AD99C9@PH0PR18MB4425.namprd18.prod.outlook.com> (raw)
In-Reply-To: <YsLyhTNSSLN9vAv+@bricha3-MOBL.ger.corp.intel.com>
Hi Bruce,
>> > >> If all devices are configured to run in IOVA mode as VA, physical
>> > >> address field of mbuf (buf_iova) won't be used.
>>
>> Will some of the hardware vendors please comment on this: Has IOVA VA mode
>become common over time, or is it still an exotic bleeding edge feature?
>>
>> If it has become common, we should let DPDK evolve accordingly, and consider
>PA (non-VA) mode legacy, treating it as such. Don't get stuck in the past.
>>
>
>IOVA as VA mode is indeed common and we are constantly encouraging users to
>switch to using vfio to try and take advantage of this.
>
>However, in my experience IOVA as PA is still very, very common too. We
>cannot drop support for this mode just yet, unfortunately.
>
>> > >> In such cases,
>> > buf_iova
>> > >> space is free to use as a dynamic field. So a new dynamic field
>> > member
>> > >> (dynfield2) is added in mbuf structure to make use of that space.
>> > >>
>> > >> A new mbuf flag RTE_MBUF_F_DYNFIELD2 is introduced to help identify
>> > the
>> > >> mbuf that can use dynfield2.
>> > >>
>> > >> Signed-off-by: Shijith Thotton <sthotton@marvell.com>
>> > >
>> > > This seems like a complex and potentially error prone way to do this.
>>
>> Perhaps this optimization should be a compile time option instead?
>>
>
>It could indeed be, and probably could be done very safely, in that we could
>mark as disabled all drivers when the mode is enabled for a build.
>Thereafter, drivers could be marked as VA-only safe as they are updated as
>necessary, i.e. use the build system to enforce that only drivers known to
>work with the mode are built when the mode is enabled.
>
I will prepare a patch to enable VA-only build.
>That said, verifying all drivers to work with this mode is a decent effort.
>Do we have indications of the perf benefit we would get from doing this for
>some real-world app?
>
next prev parent reply other threads:[~2022-08-03 15:34 UTC|newest]
Thread overview: 88+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-30 16:25 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 ` Shijith Thotton [this message]
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
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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