Andi Kleen wrote: > 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
I'll take a closer look at this, but it may have to wait until Christoph is back this Wednesday. Thanks, Mike -- 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/