netdev.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Florian Westphal <fw@strlen.de>
To: Jiri Pirko <jiri@resnulli.us>
Cc: Pablo Neira Ayuso <pablo@netfilter.org>,
	Edward Cree <ecree@solarflare.com>,
	netfilter-devel@vger.kernel.org, davem@davemloft.net,
	netdev@vger.kernel.org, kuba@kernel.org
Subject: Re: [PATCH net] net: flow_offload: skip hw stats check for FLOW_ACTION_HW_STATS_DISABLED
Date: Mon, 20 Apr 2020 15:57:54 +0200	[thread overview]
Message-ID: <20200420135754.GD32392@breakpoint.cc> (raw)
In-Reply-To: <20200420134826.GH6581@nanopsycho.orion>

Jiri Pirko <jiri@resnulli.us> wrote:
> Mon, Apr 20, 2020 at 02:39:15PM CEST, pablo@netfilter.org wrote:
> >On Mon, Apr 20, 2020 at 01:28:22PM +0100, Edward Cree wrote:
> >> On 20/04/2020 12:52, Jiri Pirko wrote:
> >> > However for TC, when user specifies "HW_STATS_DISABLED", the driver
> >> > should not do stats.
> >>
> >> What should a driver do if the user specifies DISABLED, but the stats
> >>  are still needed for internal bookkeeping (e.g. to prod an ARP entry
> >>  that's in use for encapsulation offload, so that it doesn't get
> >>  expired out of the cache)?  Enable the stats on the HW anyway but
> >>  not report them to FLOW_CLS_STATS?  Or return an error?
> >
> >My interpretation is that HW_STATS_DISABLED means that the front-end
> >does not care / does not need counters. The driver can still allocate
> 
> That is wrong interpretation. If user does not care, he specifies "ANY".
> That is the default.
> 
> When he says "DISABLED" he means disabled. Not "I don't care".

Under what circumstances would the user care about this?
Rejecting such config seems to be just to annoy user?

I mean, the user is forced to use SW datapath just because HW can't turn
off stats?!  Same for a config change, why do i need to change my rules
to say 'enable stats' even though I don't need them in first place?

Unlike the inverse (want feature X but HW can't support it), it makes
no sense to me to reject with an error here:
stats-off is just a hint that can be safely ignored.

  reply	other threads:[~2020-04-20 13:58 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-04-19 11:53 [PATCH net] net: flow_offload: skip hw stats check for FLOW_ACTION_HW_STATS_DISABLED Pablo Neira Ayuso
2020-04-20  8:02 ` Jiri Pirko
2020-04-20  9:05   ` Pablo Neira Ayuso
2020-04-20  9:13     ` Jiri Pirko
2020-04-20 10:03       ` Pablo Neira Ayuso
2020-04-20 11:52         ` Jiri Pirko
2020-04-20 12:13           ` Pablo Neira Ayuso
2020-04-20 13:49             ` Jiri Pirko
2020-04-20 12:28           ` Edward Cree
2020-04-20 12:36             ` Jiri Pirko
2020-04-20 12:49               ` Pablo Neira Ayuso
2020-04-20 13:46                 ` Jiri Pirko
2020-04-20 12:39             ` Pablo Neira Ayuso
2020-04-20 13:48               ` Jiri Pirko
2020-04-20 13:57                 ` Florian Westphal [this message]
2020-04-20 14:14                   ` Jiri Pirko
2020-04-20 19:18                     ` Pablo Neira Ayuso
2020-04-22 18:37                       ` Jiri Pirko
2020-04-27 14:31                         ` Edward Cree
2020-04-27 18:12                           ` Jakub Kicinski

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=20200420135754.GD32392@breakpoint.cc \
    --to=fw@strlen.de \
    --cc=davem@davemloft.net \
    --cc=ecree@solarflare.com \
    --cc=jiri@resnulli.us \
    --cc=kuba@kernel.org \
    --cc=netdev@vger.kernel.org \
    --cc=netfilter-devel@vger.kernel.org \
    --cc=pablo@netfilter.org \
    /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).