Re: CVS commit: src/sys/arch/xen/i386

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

On Tue, Jun 26, 2007 at 06:01:19PM +0900, YAMAMOTO Takashi wrote:
> > On Tue, Jun 26, 2007 at 07:42:48AM +0900, YAMAMOTO Takashi wrote:
> > > > Module Name:    src
> > > > Committed By:   bouyer
> > > > Date:           Mon Jun 25 20:02:45 UTC 2007
> > > > 
> > > > Modified Files:
> > > >         src/sys/arch/xen/i386: xen_intr.c
> > > > 
> > > > Log Message:
> > > > Add back a __asm("lock") that got lost in the yamt-idlelwp merge.
> > > > 
> > > > 
> > > > To generate a diff of this commit:
> > > > cvs rdiff -r1.2 -r1.3 src/sys/arch/xen/i386/xen_intr.c
> > > > 
> > > > Please note that diffs are not public domain; they are subject to the
> > > > copyright notices on the relevant files.
> > > 
> > > how could it be necessary?
> > 
> > It's not in a UP environnement, but it will probably be for SMP
> > (we're not there yet, but as I noticed it while looking at other issues :)
> > 
> > -- 
> > Manuel Bouyer <bouyer%antioche.eu.org@localhost>
> >      NetBSD: 26 ans d'experience feront toujours la difference
> > --
> 
> afaik, ci_ipending is accessed only by the corresponding processor itself.

As long as it's atomic on the local CPU, then we're in good shape. Using the
asm statement with "orl" is enough to do that, the lock prefix isn't needed.

Andrew