removal of ipi_all() and ipi_self() [Re: cvs commit: src/sys/sparc64/include smp.h src/sys/sparc64/sparc64 genassym.c mp_machdep.c]

[Marius Strobl]

On Thu, Sep 18, 2008 at 12:48:52PM -0700, Marcel Moolenaar wrote:
> 
> On Sep 18, 2008, at 12:19 PM, Marius Strobl wrote:
> 
> >On Thu, Sep 18, 2008 at 10:27:51AM -0400, John Baldwin wrote:
> >>On Thursday 18 September 2008 09:56:30 am Marius Strobl wrote:
> >>>marius      2008-09-18 13:56:30 UTC
> >>>
> >>> FreeBSD src repository
> >>>
> >>> Modified files:
> >>>   sys/sparc64/include  smp.h
> >>>   sys/sparc64/sparc64  genassym.c mp_machdep.c
> >>> Log:
> >>> SVN rev 183142 on 2008-09-18 13:56:30Z by marius
> >>>
> >>> - Newer firmware versions no longer provide SUNW,stop-self so just
> >>>   disable interrupts and loop forever with these.
> >>> - Hide all MP-related bits in <machine/smp.h> underneath #ifdef  
> >>>SMP.
> >>> - Inline ipi_all_but_self(9) and ipi_selected(9). We don't expose  
> >>>any
> >>>   additional bits but save a few cycles by doing so.
> >>> - Remove ipi_all(9), which actually only called panic(9). It  
> >>>can't be
> >>>   implemented natively anyway and having it removed at least causes
> >>>   MI users to fail already fail when linking.
> >>
> >>Should we just remove ipi_all() completely?
> >>
> >
> >Well, grepping in the CVS repository shows that there never was
> >an actually consumer of ipi_all() (only #ifdef'ed out ones in
> >ironically the sparc64 code) so it seems to be a good candidate
> >for axing. Generally I can't think of a reason why MI code would
> >want a CPU to send an IPI to itself. Actually, ipi_self() also
> >isn't and never was used in MI code, only in ia64 and powerpc
> >code for testing purposes.
> 
> That's DS (=developer-specific) code rather than MI or MD code :-)
> 
> Sending a test IPI to 'self' helps with bring-up or porting, but
> serves no real purpose (other than maybe a POST-like purpose)
> once IPIs are known to work...
> 

Okay, I take these as a call for removing ipi_all() and ipi_self()
along with the ia64 and powerpc test IPI code completely. A patch
doing just that and which passes a universe build just fine is at:
http://people.freebsd.org/~marius/nuke_ipi_all_self.diff
Does anybody object to committing it? Should __FreeBSD_version be
bumped for this?

Marius