From: Shahaf Shuler <shahafs@mellanox.com>
To: Adrien Mazarguil <adrien.mazarguil@6wind.com>,
Andrew Rybchenko <arybchenko@solarflare.com>
Cc: simei <simei.su@intel.com>,
"qi.z.zhang@intel.com" <qi.z.zhang@intel.com>,
"jingjing.wu@intel.com" <jingjing.wu@intel.com>,
"dev@dpdk.org" <dev@dpdk.org>
Subject: Re: [dpdk-dev] [PATCH 1/2] ethdev: add symmetric toeplitz hash support
Date: Wed, 31 Jul 2019 13:43:34 +0000 [thread overview]
Message-ID: <AM0PR0502MB3795D943607CCAF2995B90AAC3DF0@AM0PR0502MB3795.eurprd05.prod.outlook.com> (raw)
In-Reply-To: <20190731123040.GG4512@6wind.com>
Wednesday, July 31, 2019 3:31 PM, Adrien Mazarguil:
> Subject: Re: [dpdk-dev] [PATCH 1/2] ethdev: add symmetric toeplitz hash
> support
>
> On Wed, Jul 31, 2019 at 03:08:19PM +0300, Andrew Rybchenko wrote:
> > On 7/25/19 7:57 AM, simei wrote:
> > > From: Simei Su <simei.su@intel.com>
> > >
> > > Currently, there are DEFAULT,TOEPLITZ and SIMPLE_XOR hash funtion.
> > > To support symmetric hash by rte_flow RSS action, this patch adds
> > > new hash function "Symmetric Toeplitz" which is supported by some
> hardware.
> >
> > Isn't it a question of key to achieve symmetry?
> > I.e. hash algorithm (function) is still the same - Toeplitz, but hash
> > key makes the result symmetric (i.e. equal for flows in both
> > directions - swap transport ports and IPv4/6 addresses).
>
> This is only an option when src/dst are known in advance.
>
> When doing RSS, HW implementations (such as Mellanox's) implement a
> modified Toeplitz XOR'ing src with dst resulting in the same hash both ways
> regardless of the key.
Just to stand correct it was a bug on Mellanox kernel driver that was fixed. Now the RSS is spec complaint (non-symmetric).
Andrew is correct one can have a special key that will make the RSS symmetric, however it is good to have this option for the user to explicitly request symmetric function (w/o any restriction on the key).
>
> --
> Adrien Mazarguil
> 6WIND
next prev parent reply other threads:[~2019-07-31 13:43 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-25 4:57 [dpdk-dev] [PATCH 0/2] " simei
2019-07-25 4:57 ` [dpdk-dev] [PATCH 1/2] ethdev: " simei
2019-07-31 12:08 ` Andrew Rybchenko
2019-07-31 12:30 ` Adrien Mazarguil
2019-07-31 13:03 ` Andrew Rybchenko
2019-07-31 13:43 ` Shahaf Shuler [this message]
2019-09-29 11:51 ` Andrew Rybchenko
2019-09-30 3:12 ` Su, Simei
2019-09-30 6:14 ` Andrew Rybchenko
2019-09-30 6:34 ` Su, Simei
2019-09-30 7:49 ` Zhang, Qi Z
2019-07-25 4:57 ` [dpdk-dev] [PATCH 2/2] app/testpmd: " simei
2019-07-26 0:55 ` [dpdk-dev] [PATCH v2 0/2] " simei
2019-07-26 0:55 ` [dpdk-dev] [PATCH v2 1/2] ethdev: " simei
2019-09-28 18:32 ` Ori Kam
2019-07-26 0:55 ` [dpdk-dev] [PATCH v2 2/2] app/testpmd: " simei
2019-09-28 18:39 ` Ori Kam
2019-09-24 5:30 ` [dpdk-dev] [PATCH v2 0/2] " Zhang, Qi Z
2019-10-01 9:22 ` [dpdk-dev] [PATCH v3 " Simei Su
2019-10-01 9:22 ` [dpdk-dev] [PATCH v3 1/2] ethdev: " Simei Su
2019-10-01 13:36 ` Andrew Rybchenko
2019-10-01 9:22 ` [dpdk-dev] [PATCH v3 2/2] app/testpmd: " Simei Su
2019-10-01 15:06 ` [dpdk-dev] [PATCH v3 0/2] " Ferruh Yigit
2019-09-23 23:11 ` [dpdk-dev] [PATCH " Zhang, Qi Z
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