RE: [EXT] Re: [PATCH v3 0/5] mbuf dynamic field expansion

[Shijith Thotton <sthotton@marvell.com>]

Hi Olivier,

Thanks for the review.

>On Wed, Sep 21, 2022 at 07:26:16PM +0530, Shijith Thotton wrote:
>> This is a continuation of the discussions[1] to add mbuf physical address field to
>dynamic field.
>> Previous version was to add PA field to dynamic field area based on the EAL
>IOVA mode option. It was
>> deemed unsafe as some components could still use the PA field without
>checking IOVA mode and there
>> are drivers which need PA to work. One suggestion was to make the IOVA mode
>check at compile time so
>> that drivers which need PA can be disabled during build. This series adds this
>new meson build
>> options. Second patch adds mbuf PA field to dynamic field on such builds. Last
>two patches enable
>> Marvell cnxk PMDs and software PMDs in IOVA as VA build as they work without
>PA field.
>
>Thank you for this patchset.
>
>To be honnest, initially I was really reserved to remove the use of
>buf_iova for some specific platforms.
>
>But what made me change my mind is that the removal if buf_iova will
>likely happen in the long-term future. It looks there is a consensus on
>this. I think your patchset is a good way to prepare this transition.
>
>What is missing, I think, is a good description of the problem you are
>solving:
>
>- more space for dynamic mbuf fields -> why? can you give more detail about
>  this need?
 
Idea was to let app/lib use an additional 8-bytes of dynamic area.

>- increase performance -> you previously said that it was not your point,
>  but if we move the next field into the first cache line, I think this
>  has to be highlighted. Out of curiosity, did you made measurements?
>

I'm yet to do it. I will update, once I have the numbers.

>>
>> 1. https://urldefense.proofpoint.com/v2/url?u=https-
>3A__inbox.dpdk.org_dev_57d2ab7fff672716d37ba4078e2e3bb2db126607.1656605
>763.git.sthotton-
>40marvell.com_&d=DwIBAg&c=nKjWec2b6R0mOyPaz7xtfQ&r=G9w4KsPaQLACBf
>GCL35PtiRH996yqJDxAZwrWegU2qQ&m=O9JeIb0lfExyVnC8dV3WUADowh165KkS
>3s9JrmAjLwj8Uw5Iyb0tqSQ9YvQWpbIc&s=DaHEYGwUqUmAFmQ9Jkj8jGnOS4aw8
>iZ8Tcww-jPTdFE&e=  .
>>
>> v3:
>>  * Cleared use of buf_iova from cnxk PMD.
>>
>> v2:
>>  * Used RTE_IOVA_AS_VA instread of rte_is_iova_as_va_build().
>>  * Moved mbuf next pointer to first cacheline if RTE_IOVA_AS_VA = 1.
>>
>> Shijith Thotton (5):
>>   build: add meson option to configure IOVA mode as VA
>>   mbuf: add second dynamic field member for VA only build
>>   lib: move mbuf next pointer to first cache line
>>   drivers: mark Marvell cnxk PMDs work with IOVA as VA
>>   drivers: mark software PMDs work with IOVA as VA
>>
>>  app/test-bbdev/test_bbdev_perf.c         |  2 +-
>>  app/test-crypto-perf/cperf_test_common.c |  5 +--
>>  app/test/test_bpf.c                      |  2 +-
>>  app/test/test_dmadev.c                   | 33 ++++++--------
>>  app/test/test_mbuf.c                     | 12 +++---
>>  app/test/test_pcapng.c                   |  2 +-
>>  config/arm/meson.build                   |  8 +++-
>>  config/meson.build                       |  1 +
>>  drivers/common/cnxk/meson.build          |  1 +
>>  drivers/crypto/armv8/meson.build         |  1 +
>>  drivers/crypto/cnxk/cn10k_ipsec_la_ops.h |  4 +-
>>  drivers/crypto/cnxk/cn9k_ipsec_la_ops.h  |  2 +-
>>  drivers/crypto/cnxk/meson.build          |  2 +
>>  drivers/crypto/ipsec_mb/meson.build      |  1 +
>>  drivers/crypto/null/meson.build          |  1 +
>>  drivers/crypto/openssl/meson.build       |  1 +
>>  drivers/dma/cnxk/meson.build             |  1 +
>>  drivers/dma/skeleton/meson.build         |  1 +
>>  drivers/event/cnxk/meson.build           |  1 +
>>  drivers/event/dsw/meson.build            |  1 +
>>  drivers/event/opdl/meson.build           |  1 +
>>  drivers/event/skeleton/meson.build       |  1 +
>>  drivers/event/sw/meson.build             |  1 +
>>  drivers/mempool/bucket/meson.build       |  1 +
>>  drivers/mempool/cnxk/meson.build         |  1 +
>>  drivers/mempool/ring/meson.build         |  1 +
>>  drivers/mempool/stack/meson.build        |  1 +
>>  drivers/meson.build                      |  6 +++
>>  drivers/net/af_packet/meson.build        |  1 +
>>  drivers/net/af_xdp/meson.build           |  2 +
>>  drivers/net/bonding/meson.build          |  1 +
>>  drivers/net/cnxk/cn10k_tx.h              | 55 +++++++-----------------
>>  drivers/net/cnxk/cn9k_tx.h               | 55 +++++++-----------------
>>  drivers/net/cnxk/cnxk_ethdev.h           |  1 -
>>  drivers/net/cnxk/meson.build             |  1 +
>>  drivers/net/failsafe/meson.build         |  1 +
>>  drivers/net/memif/meson.build            |  1 +
>>  drivers/net/null/meson.build             |  1 +
>>  drivers/net/pcap/meson.build             |  1 +
>>  drivers/net/ring/meson.build             |  1 +
>>  drivers/net/tap/meson.build              |  1 +
>>  drivers/raw/cnxk_bphy/meson.build        |  1 +
>>  drivers/raw/cnxk_gpio/meson.build        |  1 +
>>  drivers/raw/skeleton/meson.build         |  1 +
>>  lib/eal/linux/eal.c                      |  7 +++
>>  lib/mbuf/rte_mbuf.c                      |  8 ++--
>>  lib/mbuf/rte_mbuf.h                      | 17 +++++---
>>  lib/mbuf/rte_mbuf_core.h                 | 55 ++++++++++++++++++------
>>  lib/mbuf/rte_mbuf_dyn.c                  |  2 +
>>  lib/meson.build                          |  3 ++
>>  lib/vhost/vhost.h                        |  2 +-
>>  lib/vhost/vhost_crypto.c                 | 54 +++++++++++++++++------
>>  meson_options.txt                        |  2 +
>>  53 files changed, 220 insertions(+), 150 deletions(-)
>>
>> --
>> 2.25.1
>>