On 15/12/06 20:41, "Hollis Blanchard" <[EMAIL PROTECTED]> wrote:
> It's an issue with any architecture with a large number of registers > which aren't automatically saved by hardware (and a C ABI that makes > some of them non-volatile). > > x86 has a small number of registers. ia64 automatically saves them (from > what I understand). So of the currently-supported architectures, yes, > that leaves PowerPC. I see. It sounds like returning from context_switch() is perhaps the right thing for powerpc. That would be easier if you have per-cpu stacks (like ia64). If not there are issues in saving register state later (and hence delaying your call to context_saved()) as there are calls to do_softirq() outside your asm code (well, not many, but there is one in domain.c for example) where you won't end up executing your do_softirq() wrapper. In general we'd like to reserve the right to include voluntary yield points, and that won't mix well with lazy register saves and per-physical-cpu stacks. -- Keir _______________________________________________ Xen-ppc-devel mailing list Xen-ppc-devel@lists.xensource.com http://lists.xensource.com/xen-ppc-devel