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

[Changwoo Min <changwoo@igalia.com>]

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