From: Stephen Hemminger <shemminger@vyatta.com>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Rick Jones <rick.jones2@hp.com>, Tom Parkin <tparkin@katalix.com>,
netdev@vger.kernel.org, David.Laight@ACULAB.COM,
James Chapman <jchapman@katalix.com>
Subject: Re: [PATCH v2] l2tp: use per-cpu variables for u64_stats updates
Date: Wed, 27 Jun 2012 13:50:34 -0700 [thread overview]
Message-ID: <20120627135034.7db7d0eb@nehalam.linuxnetplumber.net> (raw)
In-Reply-To: <1340829541.26242.90.camel@edumazet-glaptop>
On Wed, 27 Jun 2012 22:39:01 +0200
Eric Dumazet <eric.dumazet@gmail.com> wrote:
> All sane SNMP applications are ready to cope with 32bits counters
> wrapping.
Actually that statement depends on the data rate. SNMP daemons work
by polling at periodic intervals. The limit for detecting roll over depends
on the rate and the interval. I believe the ubiquitous net-snmp code uses
something a 30 second polling interval for lots of it's caches. This means
it rolls over too fast at 10G. Polling faster can help but net-snmp is
a pig about updates.
I just realized the whole x32 (running 32 bit apps on 64 bit kernel) is broken
for things like /proc/net/dev where 64 bit kernel will give 64 bit values and
the 32 bit app (like net-snmp) is expecting unsigned long (32 bits).
next prev parent reply other threads:[~2012-06-27 20:50 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-06-27 12:00 [PATCH v2] l2tp: use per-cpu variables for u64_stats updates Tom Parkin
2012-06-27 19:03 ` Eric Dumazet
2012-06-27 20:21 ` Rick Jones
2012-06-27 20:39 ` Eric Dumazet
2012-06-27 20:50 ` Stephen Hemminger [this message]
2012-06-27 20:58 ` Ben Greear
2012-06-27 21:20 ` Eric Dumazet
2012-06-27 21:31 ` Ben Greear
2012-06-27 21:35 ` Eric Dumazet
2012-06-27 23:01 ` Rick Jones
2012-06-27 23:09 ` David Miller
2012-06-27 23:39 ` Rick Jones
2012-06-28 5:00 ` Eric Dumazet
2012-06-28 8:24 ` Tom Parkin
2012-06-28 8:46 ` David Laight
2012-06-28 18:17 ` Ben Hutchings
2012-06-27 21:32 ` Eric Dumazet
2012-06-27 21:40 ` Ben Greear
2012-06-27 21:50 ` Eric Dumazet
2012-06-27 21:00 ` Rick Jones
2012-06-27 22:21 ` David Miller
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=20120627135034.7db7d0eb@nehalam.linuxnetplumber.net \
--to=shemminger@vyatta.com \
--cc=David.Laight@ACULAB.COM \
--cc=eric.dumazet@gmail.com \
--cc=jchapman@katalix.com \
--cc=netdev@vger.kernel.org \
--cc=rick.jones2@hp.com \
--cc=tparkin@katalix.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