Kernel Virtual Address Space

Sridhar Chellappa schellap at spinnakernet.com
Thu Jan 29 12:12:10 PST 2004


As part of the Bootup sequence, I see create_pagetables allocate only 30 
Pages for Page Table entries in non-PAE mode and 120 pages in PAE mode. 
Does this mean that all the kernel mode entities get only 4 * 30 * 1024 
* 1024 = 120 MB worth of Address Space ? Can I tune the kernel virtual 
address space by just changing the "NKPT" define in pmap.h ?

Also, I heard that the BSD kernel(atleast from 5.1 onward) itself is 
pre-emptible and none of the kernel threads have a cpu affinity. How do 
I change the behaviour to make the kernel non-preemptible and tie 
kernel-threads to a particular CPU ?

Sridhar.



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