[PATCH 0/4] sched_ext: Compatible testing of SCX_ENQ_CPU_SELECTED

From: Changwoo Min
Date: Fri Feb 07 2025 - 23:43:57 EST


This patchset is for testing `SCX_ENQ_CPU_SELECTED` in a compatible way.
More specifically, it handles two cases:
1. a BPF scheduler is compiled against vmlinux.h where
SCX_ENQ_CPU_SELECTED is defined, but it runs on a kernel that does not
have SCX_ENQ_CPU_SELECTED.
2. a BPF scheduler is compiling against vmlinux.h where
SCX_ENQ_CPU_SELECTED is not defined.

The patch consists of three parts:
1. Add enum_defs.autogen.h, which has macros denoting whether SCX
enums are defined in the vmlinux.h or not.
2. Implement __COMPAT_is_enq_cpu_selected(), which provide the test of
SCX_ENQ_CPU_SELECTED in a compatible way.
3. Use __COMPAT_is_enq_cpu_selected() in scx_qmap.

Also, this patchset is a sync of the relevant PR [1] in the scx repo.

[1] https://github.com/sched-ext/scx/pull/1314

Changwoo Min (4):
sched_ext: Add enum_defs.autogen.h
sched_ext: Include enum_defs.autogen.h from common/common.bpf.h
sched_ext: Add __COMPAT_is_enq_cpu_selected() for BPF compatability
sched_ext: Use __COMPAT_is_enq_cpu_selected() in scx_qmap

tools/sched_ext/include/scx/common.bpf.h | 1 +
tools/sched_ext/include/scx/common.h | 1 +
tools/sched_ext/include/scx/compat.bpf.h | 52 ++++++++
.../sched_ext/include/scx/enum_defs.autogen.h | 120 ++++++++++++++++++
tools/sched_ext/scx_qmap.bpf.c | 2 +-
5 files changed, 175 insertions(+), 1 deletion(-)
create mode 100644 tools/sched_ext/include/scx/enum_defs.autogen.h

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2.48.1