From: Tejun Heo Date: Fri, 10 Apr 2026 17:54:06 +0000 (-1000) Subject: sched_ext: Add select_cpu kfuncs to scx_kfunc_ids_unlocked X-Git-Tag: ceph-for-7.1-rc4~252^2~12 X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=a37e134317c68941fb3e0a4890d95de41eac63f5;p=ceph-client.git sched_ext: Add select_cpu kfuncs to scx_kfunc_ids_unlocked select_cpu_from_kfunc() has an extra scx_kf_allowed_if_unlocked() branch that accepts calls from unlocked contexts and takes task_rq_lock() itself - a "callable from unlocked" property encoded in the kfunc body rather than in set membership. That's fine while the runtime check is the authoritative gate, but the upcoming verifier-time filter uses set membership as the source of truth and needs it to reflect every context the kfunc may be called from. Add the three select_cpu kfuncs to scx_kfunc_ids_unlocked so their full set of callable contexts is captured by set membership. This follows the existing dual-set convention used by scx_bpf_dsq_move{,_vtime} and scx_bpf_dsq_move_set_{slice,vtime}, which are members of both scx_kfunc_ids_dispatch and scx_kfunc_ids_unlocked. While at it, add brief comments on each duplicate BTF_ID_FLAGS block (including the pre-existing dsq_move ones) explaining the dual membership. No runtime behavior change: the runtime check in select_cpu_from_kfunc() remains the authoritative gate until it is removed along with the rest of the scx_kf_mask enforcement in a follow-up. v2: Clarify dispatch-set comment to name scx_bpf_dsq_move*() explicitly so it doesn't appear to cover scx_bpf_sub_dispatch() (Andrea Righi). Signed-off-by: Tejun Heo Reviewed-by: Andrea Righi --- diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c index b757b853b42b..11a8f936ecc1 100644 --- a/kernel/sched/ext.c +++ b/kernel/sched/ext.c @@ -8497,6 +8497,7 @@ BTF_ID_FLAGS(func, scx_bpf_dispatch_nr_slots, KF_IMPLICIT_ARGS) BTF_ID_FLAGS(func, scx_bpf_dispatch_cancel, KF_IMPLICIT_ARGS) BTF_ID_FLAGS(func, scx_bpf_dsq_move_to_local, KF_IMPLICIT_ARGS) BTF_ID_FLAGS(func, scx_bpf_dsq_move_to_local___v2, KF_IMPLICIT_ARGS) +/* scx_bpf_dsq_move*() also in scx_kfunc_ids_unlocked: callable from unlocked contexts */ BTF_ID_FLAGS(func, scx_bpf_dsq_move_set_slice, KF_RCU) BTF_ID_FLAGS(func, scx_bpf_dsq_move_set_vtime, KF_RCU) BTF_ID_FLAGS(func, scx_bpf_dsq_move, KF_RCU) @@ -8612,10 +8613,15 @@ __bpf_kfunc_end_defs(); BTF_KFUNCS_START(scx_kfunc_ids_unlocked) BTF_ID_FLAGS(func, scx_bpf_create_dsq, KF_IMPLICIT_ARGS | KF_SLEEPABLE) +/* also in scx_kfunc_ids_dispatch: also callable from ops.dispatch() */ BTF_ID_FLAGS(func, scx_bpf_dsq_move_set_slice, KF_RCU) BTF_ID_FLAGS(func, scx_bpf_dsq_move_set_vtime, KF_RCU) BTF_ID_FLAGS(func, scx_bpf_dsq_move, KF_RCU) BTF_ID_FLAGS(func, scx_bpf_dsq_move_vtime, KF_RCU) +/* also in scx_kfunc_ids_select_cpu: also callable from ops.select_cpu()/ops.enqueue() */ +BTF_ID_FLAGS(func, __scx_bpf_select_cpu_and, KF_IMPLICIT_ARGS | KF_RCU) +BTF_ID_FLAGS(func, scx_bpf_select_cpu_and, KF_RCU) +BTF_ID_FLAGS(func, scx_bpf_select_cpu_dfl, KF_IMPLICIT_ARGS | KF_RCU) BTF_KFUNCS_END(scx_kfunc_ids_unlocked) static const struct btf_kfunc_id_set scx_kfunc_set_unlocked = { diff --git a/kernel/sched/ext_idle.c b/kernel/sched/ext_idle.c index cd88aee47bd8..8c31fb65477c 100644 --- a/kernel/sched/ext_idle.c +++ b/kernel/sched/ext_idle.c @@ -1482,6 +1482,10 @@ static const struct btf_kfunc_id_set scx_kfunc_set_idle = { * contexts where @p's pi_lock state is unknown. Keep them out of * BPF_PROG_TYPE_TRACING by registering them in their own set which is exposed * only to STRUCT_OPS and SYSCALL programs. + * + * These kfuncs are also members of scx_kfunc_ids_unlocked (see ext.c) because + * they're callable from unlocked contexts in addition to ops.select_cpu() and + * ops.enqueue(). */ BTF_KFUNCS_START(scx_kfunc_ids_select_cpu) BTF_ID_FLAGS(func, __scx_bpf_select_cpu_and, KF_IMPLICIT_ARGS | KF_RCU)