Bug 31218

Summary:	kernel-5.15.79 really slow detecting bttv devices - regression since 5.15.74
Product:	Mageia	Reporter:	Barry Jackson <zen25000>
Component:	RPM Packages	Assignee:	Kernel and Drivers maintainers <kernel>
Status:	NEW ---	QA Contact:
Severity:	normal
Priority:	Normal	CC:	davidwhodgins, tmb
Version:	8
Target Milestone:	---
Hardware:	All
OS:	Linux
Whiteboard:
Source RPM:	kernel-xxxxxx-5-15.79	CVE:
Status comment:
Attachments:	Normal boot with 5.15.74 Slow boot with 5.15.79

Description Barry Jackson 2022-12-04 14:30:45 CET

Description of problem:
My server has 2 bttv video capture cards with 8 devices per card.
During boot these are detected and initialzed.

Using kernel-5.15.74 detection of each chip takes a few seconds, however using kernel-5.15.79 the detection takes well over a minute. So for 16 devices this is around 20mins.

I have not actually waited that long as I gave up and killed the power, after about 12mins it had reached device 9 of 16 when the log stopped.

The above has been deduced afterwards studying the boot logs.

I tested both kernel-server and kernel-desktop flavours of 5.15.79.

Comment 1 Barry Jackson 2022-12-04 14:32:05 CET

Created attachment 13540 [details]
Normal boot with 5.15.74

Comment 2 Barry Jackson 2022-12-04 14:33:28 CET

Created attachment 13541 [details]
Slow boot with 5.15.79

Comment 3 Lewis Smith 2022-12-04 20:08:16 CET

Thank you for the report, which is clear enough.

Assigning to kernel.

Assignee: bugsquad => kernel

Comment 4 Dave Hodgins 2022-12-04 20:23:23 CET

Two recommendations unrelated to the actual problem

Add lines with
SystemMaxUse=200M
RuntimeMaxUse=200M
to the end of /etc/systemd/journald.conf

That will reduce the size of the journal from it's current 10% of the root
partition size (2.3GB) to around 200M. On my system that's about 30 days
normally. Increase/decrease as needed.

Add "audit=0" to the kernel boot parameters. Unless you are using audit the
messages clutter the journal.

CC: (none) => davidwhodgins

Comment 5 Barry Jackson 2022-12-05 00:46:02 CET

Thanks Dave - done that, I was a bit concerned about the journal size.

Barry Jackson 2022-12-06 12:44:34 CET

CC: (none) => tmb