netdev.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Jakub Kicinski <kuba@kernel.org>
To: Alexander Lobakin <aleksander.lobakin@intel.com>
Cc: Edward Cree <ecree.xilinx@gmail.com>, <davem@davemloft.net>,
	<netdev@vger.kernel.org>, <edumazet@google.com>,
	<pabeni@redhat.com>, <willemb@google.com>, <fw@strlen.de>
Subject: Re: [PATCH net-next 2/3] net: skbuff: cache one skb_ext for use by GRO
Date: Wed, 15 Feb 2023 09:52:00 -0800	[thread overview]
Message-ID: <20230215095200.0d2e3b7e@kernel.org> (raw)
In-Reply-To: <f2a30934-a0fe-ae1e-0897-2bb7dc572270@intel.com>

On Wed, 15 Feb 2023 17:17:53 +0100 Alexander Lobakin wrote:
> > On 15/02/2023 03:43, Jakub Kicinski wrote:  
> >> On the driver -> GRO path we can avoid thrashing the kmemcache
> >> by holding onto one skb_ext.  
> > 
> > Hmm, will one be enough if we're doing GRO_NORMAL batching?
> > As for e.g. UDP traffic up to 8 skbs (by default) can have
> >  overlapping lifetimes.
> >   
> I thought of an array of %NAPI_SKB_CACHE_SIZE to be honest. From what
> I've ever tested, no cache (for any netstack-related object) is enough
> if it can't serve one full NAPI poll :D

I was hoping to leave sizing of the cache until we have some data from
a production network (or at least representative packet traces).

NAPI_SKB_CACHE_SIZE kinda assumes we're not doing much GRO, right?
And the current patch feeds the cache exclusively from GRO...

> + agree with Paolo re napi_reuse_skb(), it's used only in the NAPI
> context and recycles a lot o'stuff already, we can speed it up safely here.

LMK what's your opinion on touching the other potential spots, too.
(in Paolo's subthread).

  reply	other threads:[~2023-02-15 17:52 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-02-15  3:43 [PATCH net-next 0/3] net: skbuff: cache one skb_ext for use by GRO Jakub Kicinski
2023-02-15  3:43 ` [PATCH net-next 1/3] net: skb: carve the allocation out of skb_ext_add() Jakub Kicinski
2023-02-15  3:43 ` [PATCH net-next 2/3] net: skbuff: cache one skb_ext for use by GRO Jakub Kicinski
2023-02-15  8:41   ` Paolo Abeni
2023-02-15 17:45     ` Jakub Kicinski
2023-02-15 18:08       ` Alexander Lobakin
2023-02-15 19:08         ` Paolo Abeni
2023-02-15 15:37   ` Edward Cree
2023-02-15 16:17     ` Alexander Lobakin
2023-02-15 17:52       ` Jakub Kicinski [this message]
2023-02-15 18:01         ` Alexander Lobakin
2023-02-15 18:20           ` Jakub Kicinski
2023-02-16 12:04             ` Alexander Lobakin
2023-02-15  3:43 ` [PATCH net-next 3/3] net: create and use NAPI version of tc_skb_ext_alloc() Jakub Kicinski
2023-02-15 16:50   ` Jamal Hadi Salim
2023-02-15 17:03     ` Jiri Pirko
2023-02-15 18:36       ` Jamal Hadi Salim
2023-02-15 17:35     ` Jakub Kicinski
2023-02-15 18:38       ` Jamal Hadi Salim

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=20230215095200.0d2e3b7e@kernel.org \
    --to=kuba@kernel.org \
    --cc=aleksander.lobakin@intel.com \
    --cc=davem@davemloft.net \
    --cc=ecree.xilinx@gmail.com \
    --cc=edumazet@google.com \
    --cc=fw@strlen.de \
    --cc=netdev@vger.kernel.org \
    --cc=pabeni@redhat.com \
    --cc=willemb@google.com \
    /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).