On Fri, Jul 14, 2023 at 03:39:06PM +0200, Peter Zijlstra wrote: > + /* > + * Encode the futex size in the offset. This makes cross-size > + * wake-wait fail -- see futex_match(). > + * > + * NOTE that cross-size wake-wait is fundamentally broken wrt > + * FLAGS_NUMA but could possibly work for !NUMA. > + */ > + key->both.offset |= FUT_OFF_SIZE * (flags & FLAGS_SIZE_MASK); this wee bit should've gone in patch 9.