Re: CVS commit: src/sys

[Lars Heidieker <lars.heidieker%googlemail.com@localhost>]

On Thu, Feb 17, 2011 at 8:27 PM, Matt Thomas <matt%netbsd.org@localhost> wrote:
> Module Name:    src
> Committed By:   matt
> Date:           Thu Feb 17 19:27:13 UTC 2011
>
> Modified Files:
>        src/sys/kern: kern_kthread.c
>        src/sys/uvm: uvm_extern.h uvm_glue.c
>
> Log Message:
> Add support for cpu-specific uarea allocation routines.  Allows different
> allocation for user and system lwps.  MIPS will use this to map uareas of
> system lwp used direct-mapped addresses (to reduce the overhead of
> switching to kernel threads).  ibm4xx could use to map uareas via direct
> mapped addresses and avoid the problem of having the kernel stack not in
> the TLB.
>
>
> To generate a diff of this commit:
> cvs rdiff -u -r1.30 -r1.31 src/sys/kern/kern_kthread.c
> cvs rdiff -u -r1.170 -r1.171 src/sys/uvm/uvm_extern.h
> cvs rdiff -u -r1.147 -r1.148 src/sys/uvm/uvm_glue.c
>
> Please note that diffs are not public domain; they are subject to the
> copyright notices on the relevant files.
>
>

Hi, I get the idea of this change but not quite complete.
First I got the a compile error on amd64, thats what made me look at it.
An ifdef arround the initialization of the uvm_uarea_system_cache is missing.
What are the cpu_uarea_alloc functions supposed to do, differently
from the PMAP_MAP_POOLPAGE approach, I guess they are able to alloc
multiplies of PAGE_SIZE with the correct alignment, if so once they
are in place the PMAP_MAP_POOLPAGE is not required any more?
I think MIPS currently uses PMAP_MAP_POOLPAGE.
And why treat system lwp uareas differently from user ones?

Sorry if I miss something here.

Greetings,
Lars

-- 
Mystische Erklärungen:
Die mystischen Erklärungen gelten für tief;
die Wahrheit ist, dass sie noch nicht einmal oberflächlich sind.
   -- Friedrich Nietzsche
   [ Die Fröhliche Wissenschaft Buch 3, 126 ]