On Thu, Dec 08, 2016 at 01:49:28PM +0100, Thomas Gleixner wrote: > > > > - if (logical_packages > __max_logical_packages) { > > > - pr_warn("Detected more packages (%u), then computed by BIOS > > > data (%u).\n", > > > - logical_packages, __max_logical_packages); > > > - logical_packages_frozen = true; > > > - __max_logical_packages = logical_packages; > > > > So we'll never 'shrink' the initially computed max; which could result > > in using more memory than strictly needed, otoh it makes physical > > hotplug happier. > > Yes. I was debating that back and forth and at the end decided that making > it simple and robust is a good tradeoff vs. the slightly higher memory > consumption. Though on most systems that's a non issue as number of > possible cpus/packages is the same as the actual available ones. The insane > setups have to suffer - rightfully so.
Don't we overestimate by a factor of 2 due to HT? That is, every single socket Intel box will have a max_packages of 2. Not that I care too deeply, and arguably the HT case _is_ insane because its impossible to tell etc..