On Thu, 3 Aug 2006, Andi Kleen wrote: > > I still wonder why you are so focused on ifdefs. Why would we need those? > > Because the Xen drivers will run on a couple of architectures, including > IA64 and PPC. > > If IA64 or PPC didn't implement at least wrappers for the sync ops > then they would all need special ifdefs to handle this. No they would just need to do an #include <xen-bitops.h> > > Maybe the best thing would be to have proper atomic ops in UP mode on > > i386? The current way of just dropping the lock bit is the source of the > > troubles. > > It's a huge performance difference. I understand but why dont we use regular ops explicitly instead of hacking the atomic ops. Then we would not have unhack them now. > > Just adding a single line #include <asm/xen-bitops.h> to drivers that need > > this functionality is not an undue burden for the drivers that support > > Xen. They have to use special _xxx bitops anyways. > > Ok it could be put into a separate file (although with a neutral name) > > But you would still need to add that to IA64, PPC etc. too, so it > would only avoid adding a single to the other architectures. Could we not just add one fallback definition to asm-generic?
