On 03 February 2020 at 6:53 pm, Jakub Kicinski wrote:

On Sun, 2 Feb 2020 16:02:18 +0100, Christian Zigotzky wrote:

quoted

On 02 February 2020 at 09:19 am, Christophe Leroy wrote:

quoted

Hello,

Le 02/02/2020 à 01:08, Christian Zigotzky a écrit :

quoted

Hello,

We regularly compile and test Linux kernels every day during the
merge window. Since Thursday we have very high CPU loads because of
the avahi daemon on our desktop Linux systems (Ubuntu, Debian etc).

Error message: avahi-daemon[2410]: ioctl(): Inappropriate ioctl for
device

Do you know which ioctl, on which device ?
Can you take a trace of running avahi-daemon with 'strace' ?

Can you bisect ?

Christophe

Hi Christophe,
Hi All,

I figured out that the avahi-daemon has a problem with the IPv6 address
of a network interface since the Git kernel from Thursday. (Log attached)
This generates high CPU usage because the avahi-daemon tries to access
the IPv6 address again and again and thereby it produces a lot of log
messages.

We figured out that the networking updates aren't responsible for this
issue because we created a test kernel on Wednesday. The issue is
somewhere in the commits from Wednesday night to Thursday (CET).

FWIW Thursday is when the latest networking pull came in, so could well
be networking related..

quoted

Please compile the latest Git kernel and test it with a desktop linux
distribution for example Ubuntu. In my point of view there are many
desktop machines affected. Many server systems don't use the avahi
daemon so they aren't affected.

It's possible to deactivate the access to the IPv6 address with the
following line in the file "/etc/avahi/avahi-daemon.conf":

use-ipv6=no

After a reboot the CPU usage is normal again. This is only a temporary
solution.

Unfortunately I don't have the time for bisecting next week. I have a
lot of other work to do. In my point of view it is very important that
you also compile the latest Git kernels. Then you will see the issue and
then you have a better possibility to fix the issue.

Hi All,

The issue still exist in the latest Git kernel. It's a PowerPC issue. I 
compiled the latest Git kernel on a PC today and there aren't any issues 
with the avahi daemon. Another Power Mac user reported the same issue on 
his G5. I tested with the AmigaOne X1000 and X5000 in the last days.

I bisected today but I think the result isn't correct because it founds 
the other problem with ordering of PCSCSI definition in esp_rev enum. I 
don't know how to bisect if there is another issue at the same time. 
Maybe "git bisect skip"?

2086faae3c55a652cfbd369e18ecdb703aacc493 is the first bad commit
commit 2086faae3c55a652cfbd369e18ecdb703aacc493
Author: Kars de Jong [off-list ref]
Date:   Tue Nov 19 21:20:20 2019 +0100

     scsi: esp_scsi: Correct ordering of PCSCSI definition in esp_rev enum

     The order of the definitions in the esp_rev enum is important. The 
values
     are used in comparisons for chip features.

     Add a comment to the enum explaining this.

     Also, the actual values for the enum fields are irrelevant, so 
remove the
     explicit values (suggested by Geert Uytterhoeven). This makes 
adding a new
     field in the middle of the enum easier.

     Finally, move the PCSCSI definition to the right place in the enum. 
In its
     previous location, at the end of the enum, the wrong values are 
written to
     the CONFIG3 register when used with FAST-SCSI targets.

     Link: 
https://lore.kernel.org/r/20191119202021.28720-2-jongk@linux-m68k.org (local)
     Signed-off-by: Kars de Jong [off-list ref]
     Signed-off-by: Martin K. Petersen [off-list ref]

:040000 040000 cdc128596e33fb60406b5de9b17b79623c187c1a 
48ceab06439f95285e8b30181e75f9a68c25fcb5 M    drivers

Cheers,
Christian