On Fri, Apr 05, 2019 at 01:08:58PM +0200, Florian Weimer wrote: > * Peter Zijlstra: > > > On Fri, Apr 05, 2019 at 12:16:39PM +0200, Florian Weimer wrote: > > > >> > True; but I suppose glibc already does lots of that anyway, right? It > >> > does contain the right information. > >> > >> If I recall correctly my last investigation, > >> /sys/devices/system/cpu/possible does not reflect the size of the > >> affinity mask, either. > > > > Strictly speaking correct; the bitmap can be longer than the highest > > possible cpu number, however the remainder would be 0-padding and could > > thus be stripped without issue. > > Doesn't the kernel still enforce the larget bitmap in sched_getaffinity, > even if the bits are always zero? Oh crap, you're right. That's unfortunate I suppose.