From: Su Zhidao <[email protected]> This series does a small cleanup pass on the sched_ext bypass code path and adds a selftest for the bypass mechanism.
Patch 1 removes SCX_OPS_HAS_CGROUP_WEIGHT, which was marked deprecated in 6.15 with a "will be removed on 6.18" comment. We are now past that point. Patches 2-3 improve the bypass code in ext.c: add inline comments explaining the bypass depth counter semantics and the dequeue/enqueue re-queue loop, and replace rcu_dereference_all() with the more precise rcu_dereference_bh() in scx_bypass_lb_timerfn() which runs in softirq context. Patch 4 adds a selftest that verifies forward progress under bypass mode: worker processes are spawned while the scheduler is active, then bpf_link__destroy() is called (triggering bypass), and the test confirms all workers complete successfully. Patch 5 adds a comment to the scx_bypass_depth declaration noting its planned migration into struct scx_sched. Tested on 6.18.7 with CONFIG_SCHED_CLASS_EXT=y; all existing selftests pass. Su Zhidao (5): sched_ext: Remove deprecated SCX_OPS_HAS_CGROUP_WEIGHT flag sched_ext: Add comments to scx_bypass() for bypass depth semantics sched_ext: Use rcu_dereference_bh() in scx_bypass_lb_timerfn() sched_ext/selftests: Add bypass mode operational test sched_ext: Document scx_bypass_depth migration path kernel/sched/ext.c | 29 ++++- kernel/sched/ext_internal.h | 8 +- .../sched_ext/include/scx/enum_defs.autogen.h | 1 - tools/sched_ext/scx_flatcg.bpf.c | 2 +- tools/testing/selftests/sched_ext/Makefile | 1 + .../testing/selftests/sched_ext/bypass.bpf.c | 32 ++++++ tools/testing/selftests/sched_ext/bypass.c | 105 ++++++++++++++++++ 7 files changed, 165 insertions(+), 13 deletions(-) create mode 100644 tools/testing/selftests/sched_ext/bypass.bpf.c create mode 100644 tools/testing/selftests/sched_ext/bypass.c -- 2.43.0
