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This is problematic > because the only purpose of the warn flag is to trigger > WARN_ONCE, but the early return prevented it from ever firing, > leaving invalid task states undetected and untraced. > > To fix this, a WARN_ONCE call is now added directly in the > default case. > > The fix addresses two aspects: > > - Guarantees the invalid task states are properly logged > and traced. > > - Provides a distinct warning message > ("sched_ext: Invalid task state") specifically for > states outside the defined scx_task_state enum values, > making it easier to distinguish from other transition > warnings. > > This ensures proper detection and reporting of invalid states. > > Signed-off-by: Samuele Mariotti > Signed-off-by: Paolo Valente Nice catch, we should probably add: Fixes: f0e1a0643a59 ("sched_ext: Implement BPF extensible scheduler class") With that: Reviewed-by: Andrea Righi Thanks, -Andrea > --- > kernel/sched/ext.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c > index 1594987d637b..10683ce4e415 100644 > --- a/kernel/sched/ext.c > +++ b/kernel/sched/ext.c > @@ -2863,7 +2863,8 @@ static void scx_set_task_state(struct task_struct *p, enum scx_task_state state) > warn = prev_state != SCX_TASK_READY; > break; > default: > - warn = true; > + WARN_ONCE(1, "sched_ext: Invalid task state %d -> %d for %s[%d]", > + prev_state, state, p->comm, p->pid); > return; > } > > -- > 2.47.3 >