[PATCHSET v3 sched_ext/for-7.3] sched_ext: Split sub-scheduler implementation into sub.c

[Tejun Heo <tj@kernel.org>]

Hello,

v3: Patch 2 also exposes scx_rq_online(), scx_flush_dispatch_buf() and
    scx_kick_cpu() which scx_dispatch_sched() in sub.h calls, so that patch
    4 builds on its own (sashiko AI). Added Andrea's Reviewed-by. Patches
    1, 3 and 4 are otherwise unchanged.

v2: https://lore.kernel.org/all/20260701181046.2490390-1-tj@kernel.org
v1: https://lore.kernel.org/all/20260701031429.1892218-1-tj@kernel.org

The sub-scheduler implementation has grown and will keep growing. Move it
out of ext.c into a new kernel/sched/ext/sub.c. The first three patches are
mechanical prep (prefix file-local helpers, expose shared internals, inline
a few trivial helpers) so the move itself stays pure code motion. No
functional change.

Based on sched_ext/for-7.3 (5df6a4506d06) with sched_ext/for-7.2-fixes
(b7d9c359e5cf) assumed merged.

Tejun Heo (4):
  sched_ext: Prefix file-local ext.c helpers exposed by the sub.c split
  sched_ext: Expose the ext.c internals used by the sub.c split
  sched_ext: Inline small ext.c helpers shared across the sub.c split
  sched_ext: Split sub-scheduler implementation into sub.c

 kernel/sched/build_policy.c |    2 +
 kernel/sched/ext/ext.c      | 1122 ++++-------------------------------
 kernel/sched/ext/internal.h |  167 +++++-
 kernel/sched/ext/sub.c      |  668 +++++++++++++++++++++
 kernel/sched/ext/sub.h      |  161 +++++
 5 files changed, 1106 insertions(+), 1014 deletions(-)

Thanks.

--
tejun