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Subject: Re: mlx4en, timer irq @100%...
To: Ben RUBSON <ben.rubson@gmail.com>, FreeBSD Net <freebsd-net@freebsd.org>
References: <BF3A3E47-A726-49FB-B83F-666EFC5C0FF1@gmail.com>
From: Hans Petter Selasky <hps@selasky.org>
Message-ID: <72b9de84-5572-3737-b274-34d2c5cdf634@selasky.org>
Date: Fri, 4 Aug 2017 19:02:38 +0200
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On 08/04/17 18:59, Ben RUBSON wrote:
> Hello,
> 
> Not sure this is the right list, but as it seems related to a mlx4en device...
> 
> # vmstat -i 1
> (...)
> interrupt                          total       rate
> cpu23:timer                         1198       1127
> 
> # top -P ALL
> (...)
> CPU 23:  0.0% user,  0.0% nice,  0.0% system,  100% interrupt,  0.0% idle
> 
> # netstat -I mlxen0 -d -w 1
>              input         mlxen0           output
>     packets  errs idrops      bytes    packets  errs      bytes colls drops
> (and not output at all, same for mlxen1 !)
> 
> # uname -sr
> FreeBSD 11.0-RELEASE-p9
> 
> So, as you can see, one of my CPUs is used at 100% by timer interrupts,
> since about 2 hours, and suddenly.
> Initiating network connections to this server is now slow.
> And what I found is that I can't use netstat on my 2 mlx4en devices anymore
> (my monitoring tool is then no more fed).
> 
> sysctl hw.mlxen0 is OK, no errors, and trafic counters grow slowly.
> 
> What should I do ?
> How to investigate on this ?
> 
> Thank you very much for your help & support,
> 

Hi,

Try "procstat -ak". It should give an idea what is going on.

What version of FreeBSD is this?

Is this a regression issue?

--HPS