On 02/16/2012 11:30 AM, Alexander Graf wrote: > > On 16.02.2012, at 18:28, Scott Wood wrote: > >> On 02/16/2012 11:18 AM, Alexander Graf wrote: >>> Hrm. But we can clobber ctr, right? So how about we make the generic version do a bctr and then just do a small C wrapper that takes lr, moves it to ctr and branches to the generic one? >> >> If it's just for this, I would say don't mess with the normal hcall path >> for the sake of idle. If using CTR would let us get away without >> creating a stack frame in call sites, maybe that would be worthwhile, >> depending on what sort of hcalls we end up having. >> >>> Then we don't have to replicate the hypercall code all over again for every invocation. >> >> We shouldn't need to do it for every invocation. Idle is special due to >> the TLF_NAPPING hack. > > Famous last words. If it's the only case, duplication should be ok. Let's hope there are no others. Actually, we can't use CTR -- it's volatile in the ePAPR hypercall ABI. -Scott -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
