Re: pserialize(9) vs. TAILQ

[Eduardo Horvath <eeh%NetBSD.org@localhost>]

On Fri, 21 Nov 2014, Dennis Ferguson wrote:

> On 21 Nov, 2014, at 00:22 , Eduardo Horvath <eeh%NetBSD.org@localhost> wrote:
> > Or you could try to get the kernel to run on a SPARC V9 machine running 
> > with RMO memory ordering.  There's a lot more of those around.  I'm not 
> > convinced the existing APIs are sufficient to get that working.
> 
> It would be worrying if the kernel wouldn't run that way.  The table from
> the McKenney paper, reproduced here
> 
>     http://en.wikipedia.org/wiki/Memory_ordering
> 
> indicates that SPARC RMO potentially reorders the same operations as
> ARMv7 and POWER.  Someone else would have to comment on how well NetBSD
> runs on multiprocessor versions of the latter processors, but it is supposed
> to and I haven't noticed any code which omits required barriers for machines
> like that (unlike the Alpha, where missing barriers for its unique quirk are
> easy to find).  The API seems sufficient.

The last time I tried it the kernel would only run in TSO mode on SPARC 
machines.  Mutexes just didn't work.

Eduardo