On Friday 28 December 2007 23:05:05 Mike Travis wrote: > Andi Kleen wrote: > > On Friday 28 December 2007 01:10:51 [EMAIL PROTECTED] wrote: > >> x86_64 provides an optimized way to determine the local per cpu area > >> offset through the pda and determines the base by accessing a remote > >> pda. > > > > And? The rationale for this patch seems to be incomplete. > > > > As far as I can figure out you're replacing an optimized percpu > > implementation which a dumber generic one. Which needs > > at least some description why. > > The specific intent for the next wave of changes coming are to reduce [...] That should be in the changelog of the patch.
Anyways the difference between the x86 percpu.h and the generic one is that x86-64 uses a short cut through the PDA to get the current cpu offset for the current CPU case. The generic one goes through smp_processor_id()->array reference instead. I would request that this optimization is not being removed without suitable replacement in the same patchkit. -Andi -- 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/
