On Fri, 21 Nov 2014, Dennis Ferguson wrote: > On 21 Nov, 2014, at 00:22 , Eduardo Horvath <e...@netbsd.org> 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