Bug 216093 - FreeBSD-11.0-RELEASE-arm-armv6-RPI2.img - ZFS NOTICE: KSTACK_PAGES is 2
Summary: FreeBSD-11.0-RELEASE-arm-armv6-RPI2.img - ZFS NOTICE: KSTACK_PAGES is 2
Status: Closed Feedback Timeout
Alias: None
Product: Base System
Classification: Unclassified
Component: arm (show other bugs)
Version: 11.0-RELEASE
Hardware: arm Any
: --- Affects Many People
Assignee: freebsd-arm (Nobody)
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2017-01-15 03:53 UTC by Slawomir Wojciech Wojtczak
Modified: 2019-10-14 13:13 UTC (History)
1 user (show)

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Description Slawomir Wojciech Wojtczak 2017-01-15 03:53:18 UTC 
Hi,

> ZFS NOTICE: KSTACK_PAGES is 2 which could result in stack overflow panic!
> Please consider adding 'options KSTACK_PAGES=4' to your kernel config

why the default kernel for FreeBSD-11.0-RELEASE-arm-armv6-RPI2.img image has KSTACK_PAGES set to only 2?

Can it be incread to '4' in GENERIC so kernel rebuild will not be necessary?

Regards,
vermaden
Comment 1 karl 2017-01-15 14:33:06 UTC 
Why not put it in /boot/loader.conf?  It is not necessary to recompile the kernel:

From my amd64 systems /boot/loader.conf files:

# Try to avoid kernel stack exhaustion due to TRIM storms.
kern.kstack_pages="6"

(Yes, TRIM "storms" can bite you even with it set to "4", and I've managed to get a panic on boot even with it set to "6" immediately after a make buildworld/installworld cycle.)
Comment 2 Slawomir Wojciech Wojtczak 2017-01-15 22:08:54 UTC 
(In reply to karl from comment #1)

Thanks, the message suggested that kernel recompile is needed. It should be modified the to tell that only /boot/loader.conf parameter is needed.

Other question then. I now have 'kern.kstack_pages=8' in /boot/loader.conf, but ZFS module STILL complains about KSTACK_PAGES at load. How to verify that ZFS module 'knows' that KSTACK_PAGES is at '8' now?
Comment 3 Slawomir Wojciech Wojtczak 2018-05-24 09:02:18 UTC 
Is this still and issue in newer releases?