On Wed, 2014-04-30 at 14:56 +1000, Benjamin Herrenschmidt wrote: > On Wed, 2014-03-19 at 17:05 -0500, Scott Wood wrote: > > On Wed, 2014-03-19 at 22:52 +0100, Christophe Leroy wrote: > > > This patch provides VIRT_CPU_ACCOUTING to PPC32 architecture. > > > Unlike PPC64, PPC32 doesn't provide the PACA register. Therefore the > > > implementation is similar to the one done in the IA64 architecture. > > > It is based on additional information added to the Task Info structure. > > > > PACA isn't a register -- just a convention for how Linux uses a GPR. > > Maybe it's time to use it on PPC32 as well? > > PACA is actually a data structure and you really really don't want it > on ppc32 :-) Having a register point to current works, having a register > point to per-cpu data instead works too (ie, change what we do today), > but don't introduce a PACA *please* :-)
What is special about 64-bit that warrants doing things differently from 32-bit? What is the difference between PACA and "per-cpu data", other than the obscure name? -Scott -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
