Re: CVS commit: src/sys

[Andrew Doran <ad%netbsd.org@localhost>]

On Thu, Oct 25, 2007 at 11:20:27AM +0900, YAMAMOTO Takashi wrote:

> > Module Name:        src
> > Committed By:       ad
> > Date:               Wed Oct 24 14:50:42 UTC 2007
> > 
> > Modified Files:
> >     src/sys/arch/acorn26/acorn26: cpuswitch.c
> >     src/sys/arch/amd64/amd64: trap.c
> >     src/sys/arch/hp300/hp300: trap.c
> >     src/sys/arch/i386/i386: trap.c
> >     src/sys/arch/mips/mips: trap.c
> >     src/sys/arch/powerpc/powerpc: trap.c
> >     src/sys/arch/sh3/sh3: locore_c.c
> >     src/sys/arch/sparc64/sparc64: trap.c
> >     src/sys/arch/xen/i386: trap.c
> >     src/sys/kern: kern_exec.c kern_exit.c kern_fork.c kern_proc.c
> >         kern_ras.c sys_process.c
> >     src/sys/sys: proc.h ras.h
> > 
> > Log Message:
> > Make ras_lookup() lockless.
> 
> is NO_SOFTWARE_PATENTS for rcu?

Strictly speaking it's not RCU but a related technique. I'm still
researching whether or not the patents apply.

> how is the kpause() version supposed to work?

- kpause + mi_switch will flush the write buffer on the calling cpu
- ras_lookup + loads in advance will take no longer than 1/8s to complete

Andrew