On Thu, Mar 29, 2018 at 06:45:12AM -0700, Dave Hansen wrote: > On 03/29/2018 06:16 AM, Thomas Gleixner wrote: > >> This is OK at least on the hardware we are immediately concerned about > >> because the LLC sharing happens at both the slice and at the package > >> level, which are also NUMA boundaries. > > So that addresses the scheduler interaction, but it still leaves the > > information in the sysfs files unchanged. See cpu/intel_cacheinfo.c. There > > are applications which use that information so it should be correct. > > Were you thinking of shared_cpu_list/map?
Yes, the fact that those are changed and the Changelog doesn't mention them is a giant fail all by itself. > The information in there is > correct for core->off-package access. It is not correct for > core->on-package access, unless that access is perfectly interleaved > across both package "slices". The fact that 'simple' measures like cache/cpu are now completely broken is a problem.