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Subsequent patches will add > -EPERM returns when the calling sub-sched lacks the required cap on the > target cid. > > Signed-off-by: Tejun Heo > --- > kernel/sched/ext.c | 13 ++++++++----- > tools/sched_ext/include/scx/common.bpf.h | 2 +- > 2 files changed, 9 insertions(+), 6 deletions(-) > > diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c > index 32ebbc351564..fedd501de67e 100644 > --- a/kernel/sched/ext.c > +++ b/kernel/sched/ext.c > @@ -9405,9 +9405,10 @@ __bpf_kfunc void scx_bpf_kick_cpu(s32 cpu, u64 flags, const struct bpf_prog_aux > * @flags: %SCX_KICK_* flags > * @aux: implicit BPF argument to access bpf_prog_aux hidden from BPF progs > * > - * cid-addressed equivalent of scx_bpf_kick_cpu(). > + * cid-addressed equivalent of scx_bpf_kick_cpu(). Return 0 on success, > + * -errno otherwise. > */ > -__bpf_kfunc void scx_bpf_kick_cid(s32 cid, u64 flags, const struct bpf_prog_aux *aux) > +__bpf_kfunc s32 scx_bpf_kick_cid(s32 cid, u64 flags, const struct bpf_prog_aux *aux) > { > struct scx_sched *sch; > s32 cpu; > @@ -9415,10 +9416,12 @@ __bpf_kfunc void scx_bpf_kick_cid(s32 cid, u64 flags, const struct bpf_prog_aux > guard(rcu)(); > sch = scx_prog_sched(aux); > if (unlikely(!sch)) > - return; > + return -ENODEV; > cpu = scx_cid_to_cpu(sch, cid); > - if (cpu >= 0) > - scx_kick_cpu(sch, cpu, flags); > + if (cpu < 0) > + return -EINVAL; Right now scx_cid_to_cpu() can only return -EINVAL, but should we propagate the error to the caller and return cpu here (in case we add more errors in the future)? Thanks, -Andrea