From: Patrick McHardy <kaber@trash.net>
To: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Brian Oostenbrink <Brian_Oostenbrink@pmc-sierra.com>,
linux-net@vger.kernel.org,
Linux Netdev List <netdev@vger.kernel.org>
Subject: Re: Re-queueing of skb in vlan_skb_recv
Date: Fri, 11 Apr 2008 15:02:06 +0200 [thread overview]
Message-ID: <47FF614E.7040500@trash.net> (raw)
In-Reply-To: <20080411125313.GI9785@ZenIV.linux.org.uk>
Al Viro wrote:
> On Fri, Apr 11, 2008 at 02:46:35PM +0200, Patrick McHardy wrote:
>> Brian Oostenbrink wrote:
>>> In vlan_skb_recv, packets are generally stripped of their vlan header,
>>> and then re-queued via netif_rx(). Is there a reason for re-queuing
>>> these instead of calling netif_receive_skb() directly? On our system
>>> (an embedded linux router), this re-queuing has a significant
>>> performance penalty.
>> Its done to save stack space. There's currently a discussion
>> about making loopback use netif_receive_skb in case enough
>> stack is still available. Once that patch gets merged I'll
>> change VLAN in a similar way.
>
> Another possibility would be to allow ->func() of packet_type to return an
> skb for reprocessing...
That should work fine for VLAN, but not for loopback since its
called on the TX path. I think I prefer Eric's suggested way
because it doesn't require to change all the other existing
packet_type users.
next prev parent reply other threads:[~2008-04-11 13:02 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <8A9D56C5E50F774BABE033F1710B357601084C42@BBY1EXM11.pmc_nt.nt.pmc-sierra.bc.ca>
2008-04-11 12:46 ` Re-queueing of skb in vlan_skb_recv Patrick McHardy
2008-04-11 12:53 ` Al Viro
2008-04-11 13:02 ` Patrick McHardy [this message]
2008-04-11 17:54 ` David Miller
2008-04-13 4:47 ` Patrick McHardy
2008-04-11 12:53 ` Jeremy Jackson
2008-04-11 13:02 ` Patrick McHardy
2008-04-11 15:44 ` Stephen Hemminger
2008-04-11 16:16 ` Patrick McHardy
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=47FF614E.7040500@trash.net \
--to=kaber@trash.net \
--cc=Brian_Oostenbrink@pmc-sierra.com \
--cc=linux-net@vger.kernel.org \
--cc=netdev@vger.kernel.org \
--cc=viro@ZenIV.linux.org.uk \
/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).