On Fri, Mar 14, 2014 at 06:58:55PM +0900, HATAYAMA Daisuke wrote:
[..]
Vivek, do you plan to write configuration of nr_cpus in any
document?
Increasing nr_cpus increases amount of memory consumption in 2nd kernel,
and particular kind of modules consumes memory in proportion to the number
of logical cpus or local apic. It's cumbersome to automate configuring
nr_cpus setting by script while estimating amount of memory. So for manual
setting, notes on nr_cpus should be documented anywhere.
I agree that we should document nr_cpus and its impact on kdump. Possibly
we can put few lines in kexec-kdump-howto.txt. Would you like to send
a patch. We can also talk of disable_apic_id usage in same paragraph.
Also I had a question. One reason you wanted to bring up multiple cpus
in second kernel so that one can do compression in parallel on large
machines.
How to use that functionality.
Thanks
Vivek