Kernel Options

T <[email protected]> Tue, 19 Nov 2019 18:57:26 -0700
Newsgroups gmane.os.netbsd.ports.prep
Message-ID <[email protected]>
Hello,
I've been trying out some kernel options and wanted to document a few 
things on here, and to perhaps see if other similar peer machines are 
also having the same results. Here's a list of the options with brief notes:

options DIAGNOSTIC
#Causes the kernel to panic, after the bootloader stage. This was 
enabled for the secondary kernel, did not have it enabled in the 
bootloader kernel.

options KGDB
#This will lead to compile errors if enabled. I was able to track down 
the errors to some changes that were made that did not take OEA type 
machines into consideration. I was able to move some IFDEF tags to fix, 
although there was one error I could not figure out, but was able to 
bypass in order to get the kernel to compile. I'll follow up with more 
information/patch when I return to this issue.

options BUFQ_READPRIO
#When this was enabled, it fixed a problem where the UI would appear to 
become stuck. Large amounts of IO to external storage devices through 
PCI bus adapters (i.e. SATA, USB) would trigger this problem. I have 
updated this ticket with more specific information: 
http://gnats.netbsd.org/33291

options BUFQ_PRIOCSCAN
#This causes the kernel to panic. I tried to enable it because many of 
the other ports have it enabled by default and was curious if it would 
also fix the problem mentioned directly above. I was told that this is 
the better buffer queue strategy, which would explain why the above 
buffer queue strategy is rarely enabled in the default kernel 
configuration files of other ports. I have yet to try FCFS, but probably 
will in the near future. Some background on " Buffer Queue Strategies": 
https://mail-index.netbsd.org/netbsd-users/2015/12/02/msg017432.html

I will submit these to gnats if I can get some sort of confirmation that 
these are reproducible on a different machine. If more information is 
needed, let me know.