From: Eric Dumazet <eric.dumazet@gmail.com>
To: Roman Yeryomin <leroi.lists@gmail.com>
Cc: Dave Taht <dave.taht@gmail.com>,
make-wifi-fast@lists.bufferbloat.net,
"codel@lists.bufferbloat.net" <codel@lists.bufferbloat.net>,
ath10k <ath10k@lists.infradead.org>
Subject: Re: [Make-wifi-fast] fq_codel_drop vs a udp flood
Date: Mon, 02 May 2016 08:01:42 -0700 [thread overview]
Message-ID: <1462201302.5535.245.camel@edumazet-glaptop3.roam.corp.google.com> (raw)
In-Reply-To: <CACiydbJStMOr0HKpw68zxDPgQRdwjR88aDis9fv12umzKAvWqw@mail.gmail.com>
On Mon, 2016-05-02 at 16:47 +0300, Roman Yeryomin wrote:
> So it looks to me that fq_codel is just broken if it needs half of my resources.
Agreed.
When I wrote fq_codel, I was not expecting that one UDP socket could
fill fq_codel with packets, since we have standard backpressure.
SO_SNDBUF default on UDP does not allow to send more than 256 packets in
a qdisc. So when sk_sndbuf limit is hit, sendmsg() either blocks or
returns an error (if in non blocking mode)
So it looks like someone really tries hard ;)
To reproduce the issue I had to change (as root user)
echo 1000000 >/proc/sys/net/core/wmem_default
_and_ setup fq_codel with a much lower limit than the default 10240
limit
tc qdisc replace dev eth0 root fq_codel limit 300
So please try this fix :
https://patchwork.ozlabs.org/patch/617307/
prev parent reply other threads:[~2016-05-02 15:01 UTC|newest]
Thread overview: 80+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-01 3:41 Dave Taht
2016-05-01 4:46 ` Jonathan Morton
2016-05-01 5:08 ` Ben Greear
2016-05-01 5:23 ` Dave Taht
2016-05-01 14:47 ` dpreed
[not found] ` <CAJq5cE2woA3yb6i_7NLPpxjzvhsVk5uL8BnSTAY7Lp-M0KiPNg@mail.gmail.com>
[not found] ` <CAJq5cE2K0yrz6ALAoKWu23RSJZX9Y_P7Mqcy9ba8e-L3AVhOaA@mail.gmail.com>
2016-05-01 15:51 ` Jonathan Morton
2016-05-02 14:03 ` Roman Yeryomin
2016-05-02 18:40 ` Dave Taht
2016-05-02 20:17 ` [Make-wifi-fast] [Codel] " Isaac Konikoff
2016-05-05 13:55 ` [Make-wifi-fast] " Roman Yeryomin
2016-05-05 14:55 ` Roman Yeryomin
2016-05-02 19:47 ` David Lang
2016-05-01 17:59 ` [Make-wifi-fast] [Codel] " Eric Dumazet
2016-05-01 18:20 ` Jonathan Morton
2016-05-01 18:46 ` Eric Dumazet
2016-05-01 19:55 ` Eric Dumazet
2016-05-02 7:47 ` Jesper Dangaard Brouer
2016-05-01 20:35 ` Jonathan Morton
2016-05-01 20:55 ` Eric Dumazet
2016-05-02 14:18 ` Roman Yeryomin
2016-05-02 15:07 ` Eric Dumazet
2016-05-02 15:43 ` Roman Yeryomin
2016-05-02 16:14 ` Eric Dumazet
2016-05-02 17:08 ` Dave Taht
2016-05-02 17:44 ` Eric Dumazet
2016-05-05 14:32 ` Roman Yeryomin
2016-05-05 14:53 ` Roman Yeryomin
2016-05-05 15:32 ` Dave Taht
2016-05-05 16:07 ` Roman Yeryomin
2016-05-05 16:59 ` Jonathan Morton
2016-05-05 17:39 ` Roman Yeryomin
2016-05-05 18:16 ` Dave Taht
2016-05-05 18:33 ` Dave Taht
2016-05-05 16:12 ` Eric Dumazet
2016-05-05 16:25 ` Roman Yeryomin
2016-05-05 16:42 ` Roman Yeryomin
2016-05-06 10:55 ` Roman Yeryomin
2016-05-05 19:23 ` Eric Dumazet
2016-05-05 19:41 ` Dave Taht
2016-05-06 8:41 ` moeller0
2016-05-06 11:33 ` Jesper Dangaard Brouer
2016-05-06 11:46 ` moeller0
2016-05-06 13:25 ` Eric Dumazet
2016-05-06 15:25 ` moeller0
2016-05-06 15:58 ` Eric Dumazet
2016-05-06 16:30 ` moeller0
2016-05-06 9:42 ` [Make-wifi-fast] OpenWRT wrong adjustment of fq_codel defaults (Was: [Codel] fq_codel_drop vs a udp flood) Jesper Dangaard Brouer
2016-05-06 12:47 ` Jesper Dangaard Brouer
2016-05-06 18:43 ` Roman Yeryomin
2016-05-06 18:56 ` Roman Yeryomin
2016-05-06 19:43 ` Dave Taht
2016-05-15 22:34 ` Roman Yeryomin
2016-05-15 23:07 ` Eric Dumazet
2016-05-15 23:27 ` Roman Yeryomin
2016-05-16 8:12 ` David Lang
2016-05-16 8:26 ` Roman Yeryomin
2016-05-16 8:46 ` David Lang
2016-05-16 10:34 ` [Make-wifi-fast] [OpenWrt-Devel] " Sebastian Moeller
2016-05-16 8:14 ` [Make-wifi-fast] " Roman Yeryomin
2016-05-16 14:23 ` Eric Dumazet
2016-05-16 16:04 ` Dave Taht
2016-05-16 19:46 ` Roman Yeryomin
2016-05-07 9:57 ` Kevin Darbyshire-Bryant
2016-05-15 22:47 ` Roman Yeryomin
2016-05-03 2:26 ` [Make-wifi-fast] [Codel] fq_codel_drop vs a udp flood Dave Taht
2016-05-03 5:21 ` Dave Taht
2016-05-03 12:39 ` Agarwal, Anil
2016-05-03 12:50 ` Agarwal, Anil
2016-05-03 13:35 ` Eric Dumazet
2016-05-03 15:37 ` Agarwal, Anil
2016-05-03 17:37 ` Dave Taht
2016-05-03 17:54 ` Eric Dumazet
2016-05-03 18:11 ` Dave Taht
2016-05-01 18:26 ` Dave Taht
2016-05-01 22:30 ` Eric Dumazet
2016-05-02 14:09 ` Roman Yeryomin
2016-05-02 15:04 ` Eric Dumazet
2016-05-02 15:42 ` Roman Yeryomin
2016-05-02 13:47 ` [Make-wifi-fast] " Roman Yeryomin
2016-05-02 15:01 ` Eric Dumazet [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
List information: https://lists.bufferbloat.net/postorius/lists/make-wifi-fast.lists.bufferbloat.net/
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1462201302.5535.245.camel@edumazet-glaptop3.roam.corp.google.com \
--to=eric.dumazet@gmail.com \
--cc=ath10k@lists.infradead.org \
--cc=codel@lists.bufferbloat.net \
--cc=dave.taht@gmail.com \
--cc=leroi.lists@gmail.com \
--cc=make-wifi-fast@lists.bufferbloat.net \
/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