public inbox for netdev@vger.kernel.org 
 help / color / mirror / Atom feed
From: Stephen Hemminger <stephen@networkplumber•org>
To: Ben Greear <greearb@candelatech•com>
Cc: David Miller <davem@davemloft•net>, netdev@vger•kernel.org
Subject: Re: [PATCH] igb: add module param to set max-rss-queues.
Date: Fri, 24 Mar 2017 16:14:57 -0700	[thread overview]
Message-ID: <20170324161457.13d86ee0@xeon-e3> (raw)
In-Reply-To: <255aaae0-8634-c6b5-f4aa-545d2f717aed@candelatech.com>

On Fri, 24 Mar 2017 14:20:56 -0700
Ben Greear <greearb@candelatech•com> wrote:

> On 03/24/2017 02:12 PM, David Miller wrote:
> > From: greearb@candelatech•com
> > Date: Fri, 24 Mar 2017 13:58:47 -0700
> >  
> >> From: Ben Greear <greearb@candelatech•com>
> >>
> >> In systems where you may have a very large number of network
> >> adapters, certain drivers may consume an unfair amount of
> >> IRQ resources.  So, allow a module param that will limit the
> >> number of IRQs at driver load time.  This way, other drivers
> >> (40G Ethernet, for instance), which probably will need the
> >> multiple IRQs more, will not be starved of IRQ resources.
> >>
> >> Signed-off-by: Ben Greear <greearb@candelatech•com>  
> >
> > Sorry, no module params.
> >
> > Use generic run-time facilities such as ethtool to configure
> > such things.  
> 
> You cannot call ethtool before module load time, and that is when
> the IRQs are first acquired.  It may be way more useful to give each
> of 20 network adapters 2 irqs than have the first few grab 16 and the rest
> get lumped into legacy crap.

Almost all network devices do not acquire interrupts until device is brought up.
I.e request_irq is called from open not probe. This is done so that configuration
can be done and also so that unused ports don't consume interrupt space.

  parent reply	other threads:[~2017-03-24 23:15 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-03-24 20:58 [PATCH] igb: add module param to set max-rss-queues greearb
2017-03-24 21:12 ` David Miller
2017-03-24 21:20   ` Ben Greear
2017-03-24 21:40     ` David Miller
2017-03-24 23:14     ` Stephen Hemminger [this message]
2017-03-25  1:35       ` Ben Greear
2017-03-27  9:26 ` David Laight

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=20170324161457.13d86ee0@xeon-e3 \
    --to=stephen@networkplumber$(echo .)org \
    --cc=davem@davemloft$(echo .)net \
    --cc=greearb@candelatech$(echo .)com \
    --cc=netdev@vger$(echo .)kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html
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