From: David Miller <davem@davemloft.net>
To: eric.dumazet@gmail.com
Cc: netdev@vger.kernel.org, kaber@trash.net, jarkao2@gmail.com,
hadi@cyberus.ca, shemminger@vyatta.com
Subject: Re: [PATCH] sch_sfq: avoid giving spurious NET_XMIT_CN signals
Date: Mon, 23 May 2011 17:36:13 -0400 (EDT) [thread overview]
Message-ID: <20110523.173613.2131279677585645313.davem@davemloft.net> (raw)
In-Reply-To: <1306184562.2638.14.camel@edumazet-laptop>
From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Mon, 23 May 2011 23:02:42 +0200
> While chasing a possible net_sched bug, I found that IP fragments have
> litle chance to pass a congestioned SFQ qdisc :
>
> - Say SFQ qdisc is full because one flow is non responsive.
> - ip_fragment() wants to send two fragments belonging to an idle flow.
> - sfq_enqueue() queues first packet, but see queue limit reached :
> - sfq_enqueue() drops one packet from 'big consumer', and returns
> NET_XMIT_CN.
> - ip_fragment() cancel remaining fragments.
>
> This patch restores fairness, making sure we return NET_XMIT_CN only if
> we dropped a packet from the same flow.
>
> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Looks good, applied, thanks Eric.
prev parent reply other threads:[~2011-05-23 21:37 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-05-23 21:02 [PATCH] sch_sfq: avoid giving spurious NET_XMIT_CN signals Eric Dumazet
2011-05-23 21:36 ` David Miller [this message]
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=20110523.173613.2131279677585645313.davem@davemloft.net \
--to=davem@davemloft.net \
--cc=eric.dumazet@gmail.com \
--cc=hadi@cyberus.ca \
--cc=jarkao2@gmail.com \
--cc=kaber@trash.net \
--cc=netdev@vger.kernel.org \
--cc=shemminger@vyatta.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).