On Mon, 2017-06-26 at 17:04 +0200, Peter Zijlstra wrote: > On Mon, Jun 26, 2017 at 10:55:41AM -0400, Rik van Riel wrote: > > On Mon, 2017-06-26 at 16:46 +0200, Peter Zijlstra wrote: > > > On Mon, Jun 26, 2017 at 04:44:37PM +0200, Peter Zijlstra wrote: > > > > On Fri, Jun 23, 2017 at 12:55:30PM -0400, r...@redhat.com > > > > wrote: > > > > > From: Rik van Riel <r...@redhat.com> > > > > > > > > > > The function effective_load was only used by the NUMA > > > > > balancing > > > > > code, and not by the regular load balancing code. Now that > > > > > the > > > > > NUMA balancing code no longer uses it either, get rid of it. > > > > > > > > Hmm,... funny. It used to be used by wake-affine. I'll have to > > > > go > > > > check > > > > what happened. > > > > > > Ah, it fell pray to that LLC == NUMA confusion from the previous > > > patch. > > > > > > That really looks buggered. > > > > Do the changelog or comments of that patch need fixing, > > to avoid LLC / NUMA confusion? > > Neither, I think the code is actually wrong for the case where LLC < > NUMA (a somewhat rare case these days, granted, but something that > might > still happen on !x86 perhaps).
Oh, indeed. I guess in wake_affine() we should test whether the CPUs are in the same NUMA node, rather than doing cpus_share_cache() ? Or, alternatively, have an update_numa_stats() variant for numa_wake_affine() that works on the LLC level?
