cvs commit: src/sys/vm vm_map.c
julian at elischer.org
Tue Jul 20 18:14:44 PDT 2004
Peter Wemm wrote:
>peter 2004-07-21 00:29:21 UTC
> FreeBSD src repository
> Modified files:
> sys/vm vm_map.c
> Move the initialization and teardown of pmaps to the vmspace zone's
> init and fini handlers. Our vm system removes all userland mappings at
> exit prior to calling pmap_release. It just so happens that we might
> as well reuse the pmap for the next process since the userland slate
> has already been wiped clean.
> However. There is a functional benefit to this as well. For platforms
> that share userland and kernel context in the same pmap, it means that
> the kernel portion of a pmap remains valid after the vmspace has been
> freed (process exit) and while it is in uma's cache. This is significant
> for i386 SMP systems with kernel context borrowing because it avoids
> a LOT of IPIs from the pmap_lazyfix() cleanup in the usual case.
Just thought of something..
if the kernel section of a pmap gets changed,
does the system scan all processes to fix them? and if it does, does it
do those in the cache?
I have to go look at the pmap code again....
> Tested on: amd64, i386, sparc64, alpha
> Glanced at by: alc
> Revision Changes Path
> 1.343 +2 -3 src/sys/vm/vm_map.c
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