On 23/08/24 09:47, Peter Zijlstra wrote: > On Wed, Aug 21, 2024 at 02:57:16PM -0700, Paul E. McKenney wrote: > >> 2e0199df252a ("sched/fair: Prepare exit/cleanup paths for delayed_dequeue") >> >> The preceding commit is very reliable. >> >> Only instead of (or maybe as well as?) introducing the dequeue_rt_stack() >> bug, the 2e0199df252a commit introduced a build bug: >> >> ------------------------------------------------------------------------ >> >> In file included from kernel/sched/fair.c:54: >> kernel/sched/fair.c: In function ‘switched_from_fair’: >> kernel/sched/sched.h:2154:58: error: ‘__SCHED_FEAT_DELAY_ZERO’ undeclared (first use in this function); did you mean ‘__SCHED_FEAT_LATENCY_WARN’? >> 2154 | #define sched_feat(x) !!(sysctl_sched_features & (1UL << __SCHED_FEAT_##x)) >> | ^~~~~~~~~~~~~ >> kernel/sched/fair.c:12878:21: note: in expansion of macro ‘sched_feat’ >> 12878 | if (sched_feat(DELAY_ZERO) && p->se.vlag > 0) >> | ^~~~~~~~~~ >> kernel/sched/sched.h:2154:58: note: each undeclared identifier is reported only once for each function it appears in >> 2154 | #define sched_feat(x) !!(sysctl_sched_features & (1UL << __SCHED_FEAT_##x)) >> | ^~~~~~~~~~~~~ >> kernel/sched/fair.c:12878:21: note: in expansion of macro ‘sched_feat’ >> 12878 | if (sched_feat(DELAY_ZERO) && p->se.vlag > 0) >> | ^~~~~~~~~~ >> > > Oh gawd, last minute back-merges :/ > > Does the below help any? That's more or less what it was before Valentin > asked me why it was weird like that :-) > Woops...