From: Adrien Mazarguil <adrien.mazarguil@6wind.com>
To: Thomas Monjalon <thomas@monjalon.net>
Cc: Qi Zhang <qi.z.zhang@intel.com>, dev@dpdk.org
Subject: Re: [dpdk-dev] [PATCH v2] ethdev: add fuzzy match pattern
Date: Mon, 12 Jun 2017 17:38:41 +0200 [thread overview]
Message-ID: <20170612153841.GE1758@6wind.com> (raw)
In-Reply-To: <2304112.MuvLPJetXV@xps>
On Thu, Jun 08, 2017 at 09:19:24AM +0200, Thomas Monjalon wrote:
> Hi,
>
> 08/06/2017 00:21, Qi Zhang:
> > Add new meta pattern item RTE_FLOW_TYPE_ITEM_FUZZY.
>
> I disagree about fuzzy wording, because fuzzy is something different
> I think.
At least it's a generic term, unrelated PMDs could likewise implement
another kind of fuzzy matching for performance reasons (for applications
that really care more about performance than accuracy). The fact this
particular implementation is built on top of something that is internally
known as signature hash should not be relevant.
> > This is for device that support fuzzy match option.
> > Usually a fuzzy match is fast but the cost is accuracy.
> > i.e. Signature Match only match pattern's hash value, but it is
> > possible two different patterns have the same hash value.
>
> You have described it yourself here: it matches a hash of the signature.
> Why not using "hash" as wording?
While "hash" would be also correct, in my opinion it would restrict this
pattern item to Intel adapters (ixgbe) with the ability to actually perform
a hash on patterns and use the resulting value to imperfectly match
traffic. This excludes other implementations with similar unpredictable
results.
Also a threshold notion is necessary as far as I understand, the signature
mode has several levels. The higher, the fuzzier it gets. This behavior is
difficult to translate to something generic named "hash", as one would have
to describe how the hash is computed and packets matched according to that
value, which really is ixgbe-specific at the moment.
> > Matching accuracy level can be configure by subfield threshold.
> > Driver can divide the range of threshold and map to different
> > accuracy levels that device support.
> >
> > Signed-off-by: Qi Zhang <qi.z.zhang@intel.com>
Qi, many of my other comments about v1 still stand, please check my previous
reply in any case.
--
Adrien Mazarguil
6WIND
next prev parent reply other threads:[~2017-06-12 15:38 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-05-23 23:28 [dpdk-dev] [PATCH] ethdev: add roughly " Qi Zhang
2017-05-30 12:46 ` Adrien Mazarguil
2017-05-31 7:51 ` Gaëtan Rivet
2017-06-01 1:44 ` Zhang, Qi Z
2017-06-01 14:44 ` Adrien Mazarguil
2017-06-07 22:21 ` [dpdk-dev] [PATCH v2] ethdev: add fuzzy " Qi Zhang
2017-06-08 7:19 ` Thomas Monjalon
2017-06-12 15:38 ` Adrien Mazarguil [this message]
2017-06-13 6:03 ` Zhang, Qi Z
2017-06-13 3:07 ` [dpdk-dev] [PATCH v3] ethdev: add fuzzy match in flow API Qi Zhang
2017-07-05 16:06 ` Ferruh Yigit
2017-07-05 17:55 ` Thomas Monjalon
2017-06-21 19:07 ` [dpdk-dev] [PATCH v3 0/3] net/ixgbe: enable signature match and ipv6 for consistent API Qi Zhang
2017-06-21 19:07 ` [dpdk-dev] [PATCH v3 1/3] net/ixgbe: replace macro with inline function Qi Zhang
2017-06-21 19:07 ` [dpdk-dev] [PATCH v3 2/3] net/ixgbe: enable signature match for consistent API Qi Zhang
2017-06-21 19:07 ` [dpdk-dev] [PATCH v3 3/3] net/ixgbe: enable IPv6 " Qi Zhang
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20170612153841.GE1758@6wind.com \
--to=adrien.mazarguil@6wind.com \
--cc=dev@dpdk.org \
--cc=qi.z.zhang@intel.com \
--cc=thomas@monjalon.net \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).