[3.1.1 on EL8] CPU 100% with NetworkManager

[Robert Scheck]

Hello Jana,

I see the same message with BIRD 3.1.2, however on Red Hat Enterprise Linux
9.5:

Jun  2 15:42:09 bird[72494]: I/O loop cycle took 28009.143 ms for 10 events

The message unfortunately leaves open for me whether this is bad or good or
if I even need to worry. I did not see this in BIRD 2.16 before.

I already provided my BIRD configuration related to the segmentation fault
in 3.1.1 on Tue, 20 May 2025 17:14:33 +0200 (the segmentation fault from
3.1.1 seems to be gone with 3.1.2, even don't know which changelog entry is
related to that - but thank you for fixing this!).


Regards,
  Robert

On Mon, 02 Jun 2025, Jana Babovakova via Bird-users wrote:
> Hi Zhang,
> 
> could you please provide us with more information about your situation?
> Could you send us your configuration file? What does your routing table look
> like? Are there any specific network events when BIRD complains?
> 
> Happy routing,
> Jana
> 
> Jana Babovakova (she/her) | BIRD Tech Support | CZ.NIC, z.s.p.o.
> 
> On 02. 06. 25 11:31, zx at zxinc.org wrote:
> >bird 3.1.2 seems to be far better, but still about half minutes high CPU usage:
> >6月 02 17:27:52 zx-router bird[2232668]: I/O loop cycle took 7108.812 ms for 26 events
> >6月 02 17:28:11 zx-router bird[2232668]: I/O loop cycle took 5419.657 ms for 15 events
> >6月 02 17:28:17 zx-router bird[2232668]: I/O loop cycle took 5445.657 ms for 80 events
> >
> >it's still worse comparing with 2.16.2.
> >
> >
> >
> >Zhang Xun
> >
> >发件人：zx at zxinc.org
> >发送时间： 2025-06-02 17:11
> >收件人： bird-users
> >主题： [3.1.1 on EL8] CPU 100% with NetworkManager
> >Hi there,
> >
> >When I upgrade bird from 2.16.2 to 3.1.1 today, it became unstable that it often causes CPU usage to 100% for bird,
> >and later also for NetworkManager, and there are some notable syslogs:
> >
> >6月 02 16:04:28 zx-router bird[2197971]: I/O loop cycle took 14046.255 ms for 43 events
> >6月 02 16:04:48 zx-router bird[2197971]: I/O loop cycle took 15307.277 ms for 42 events
> >6月 02 16:04:57 zx-router bird[2197971]: I/O loop cycle took 8562.921 ms for 43 events
> >6月 02 16:05:16 zx-router bird[2197971]: I/O loop cycle took 9799.271 ms for 85 events
> >6月 02 16:05:25 zx-router bird[2197971]: I/O loop cycle took 9330.265 ms for 80 events
> >6月 02 16:05:30 zx-router bird[2197971]: I/O loop cycle took 5004.867 ms for 44 events
> >6月 02 16:06:09 zx-router bird[2197971]: I/O loop cycle took 38759.438 ms for 84 events
> >6月 02 16:06:17 zx-router bird[2197971]: I/O loop cycle took 5465.396 ms for 6 events
> >6月 02 16:06:23 zx-router bird[2197971]: I/O loop cycle took 5906.858 ms for 44 events
> >6月 02 16:06:37 zx-router bird[2197971]: I/O loop cycle took 12896.032 ms for 9 events
> >6月 02 16:06:56 zx-router bird[2197971]: I/O loop cycle took 8217.969 ms for 81 events
> >6月 02 16:07:08 zx-router bird[2197971]: I/O loop cycle took 9012.775 ms for 25 events
> >6月 02 16:07:26 zx-router bird[2197971]: I/O loop cycle took 11506.570 ms for 45 events
> >6月 02 16:07:56 zx-router bird[2197971]: I/O loop cycle took 30014.580 ms for 85 events
> >6月 02 16:08:05 zx-router bird[2197971]: I/O loop cycle took 6333.289 ms for 6 events
> >6月 02 16:08:14 zx-router bird[2197971]: I/O loop cycle took 8751.816 ms for 42 events
> >6月 02 16:08:29 zx-router bird[2197971]: I/O loop cycle took 13017.064 ms for 46 events
> >6月 02 16:08:51 zx-router bird[2197971]: I/O loop cycle took 13223.357 ms for 80 events
> >6月 02 16:09:44 zx-router bird[2197971]: I/O loop cycle took 17730.328 ms for 5 events
> >6月 02 16:10:37 zx-router bird[2197971]: I/O loop cycle took 8061.950 ms for 8 events
> >6月 02 16:10:46 zx-router bird[2197971]: I/O loop cycle took 9008.065 ms for 65 events
> >6月 02 16:10:54 zx-router bird[2197971]: I/O loop cycle took 6035.965 ms for 4 events
> >6月 02 16:11:03 zx-router bird[2197971]: I/O loop cycle took 9959.243 ms for 67 events
> >
> >I'm exporting full table to kernel with NetworkManager running on RHEL8 related systems (CentOS/Alma/Rocky 8).
> >There is no problem before upgrading.