Re: [dpdk-dev] [PATCH] cryptodev: fix restore crypto op alignment and layout

[Akhil Goyal <akhil.goyal@nxp.com>]

Hi Konstantin,

On 3/7/2019 7:43 PM, Konstantin Ananyev wrote:
> in 18.08 new cache-aligned structure rte_crypto_asym_op was introduced.
> As it also was included into rte_crypto_op, it caused implicit change
> in rte_crypto_op layout and alignment: now rte_crypto_op is cahce-line
> aligned has a hole of 40/104 bytes between phys_addr and sym/asym op.
> It looks like unintended ABI breakage, plus such change can cause
> negative performance effects:
> - now status and sym[0].m_src lies on different cache-lines, so
>    post-process code would need extra cache-line read.
> - new alignment causes grow of the space requirements and cache-line
>    reads/updates for structures that contain rte_crypto_op inside.
> As there seems no actual need to have rte_crypto_asym_op cache-line
> aligned, and rte_crypto_asym_op is not intended to be used on it's own -
> the simplest fix is just to remove cache-line alignment for it.
> As the immediate positive effect: on IA ipsec-secgw performance increased
> by 5-10% (depending on the crypto-dev and algo used).
> My guess that on machines with 128B cache-line and lookaside-protocol
> capable crypto devices the impact will be even more noticeable.
>
> Fixes: 26008aaed14c ("cryptodev: add asymmetric xform and op definitions")
>
> Signed-off-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
> ---
>   doc/guides/rel_notes/release_19_05.rst | 7 +++++++
>   lib/librte_cryptodev/Makefile          | 2 +-
>   lib/librte_cryptodev/meson.build       | 2 +-
>   lib/librte_cryptodev/rte_crypto_asym.h | 2 +-
>   4 files changed, 10 insertions(+), 3 deletions(-)
>
> diff --git a/doc/guides/rel_notes/release_19_05.rst b/doc/guides/rel_notes/release_19_05.rst
> index c0390ca16..ec2651b65 100644
> --- a/doc/guides/rel_notes/release_19_05.rst
> +++ b/doc/guides/rel_notes/release_19_05.rst
> @@ -116,6 +116,13 @@ ABI Changes
>      Also, make sure to start the actual text at the margin.
>      =========================================================
>   
> +* cryptodev: in 18.08 new structure ``rte_crypto_asym_op`` was introduced and
> +  included into ``rte_crypto_op``. As ``rte_crypto_asym_op`` structure was
> +  defined as cache-line aligned that caused unintended changes in
> +  ``rte_crypto_op`` structure layout and alignment. Remove cache-line
> +  alignment for ``rte_crypto_asym_op`` to restore expected ``rte_crypto_op``
> +  layout and alignment.
> +
>   
ABI version should be bumped in the release notes as well. I will update 
that while merging.
Apart from that
Acked-by: Akhil Goyal <akhil.goyal@nxp.com>
>   Shared Library Versions
>   -----------------------
>