From: Zhao Mengmeng <zhaomengmeng@kylinos.cn>

Newer kernels generate SCX_ENQ_IMMED from enums.autogen.bpf.h,
while compat.bpf.h still defines a fallback macro unconditionally.
Including both headers then triggers a macro redefinition warning
when building BPF schedulers.

warning: 'SCX_ENQ_IMMED' macro redefined [-Wmacro-redefined]

Fix it by defining the compat fallback only when HAVE_SCX_ENQ_IMMED
is absent.

Fixes: 98d709cba319 ("sched_ext: Implement SCX_ENQ_IMMED")
Signed-off-by: Zhao Mengmeng <zhaomengmeng@kylinos.cn>
---
 tools/sched_ext/include/scx/compat.bpf.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/tools/sched_ext/include/scx/compat.bpf.h b/tools/sched_ext/include/scx/compat.bpf.h
index 654b566bd94a..52e6fb9ea211 100644
--- a/tools/sched_ext/include/scx/compat.bpf.h
+++ b/tools/sched_ext/include/scx/compat.bpf.h
@@ -425,7 +425,9 @@ static inline void scx_bpf_dsq_reenq(u64 dsq_id, u64 reenq_flags)
 /*
  * v7.1: %SCX_ENQ_IMMED.
  */
+#ifndef HAVE_SCX_ENQ_IMMED
 #define SCX_ENQ_IMMED	__COMPAT_ENUM_OR_ZERO(enum scx_enq_flags, SCX_ENQ_IMMED)
+#endif
 
 /*
  * Define sched_ext_ops. This may be expanded to define multiple variants for
-- 
2.43.0

Hello,

The compat fallback isn't necessary anymore as the autogen definition
through const volatile __weak already resolves to 0 on older kernels.
I just removed it instead.

Thanks.

--
tejun

compat.bpf.h defined a fallback SCX_ENQ_IMMED macro using
__COMPAT_ENUM_OR_ZERO(). After 6bf36c68b0a2 ("tools/sched_ext:
Regenerate autogen enum headers") added SCX_ENQ_IMMED to the autogen
headers, including both triggers -Wmacro-redefined warnings.

The autogen definition through const volatile __weak already resolves to
0 on older kernels, providing the same backward compatibility. Remove
the now-redundant compat fallback.

Fixes: 6bf36c68b0a2 ("tools/sched_ext: Regenerate autogen enum headers")
Link: https://lore.kernel.org/r/20260326100313.338388-1-zhaomzhao@126.com
Reported-by: Zhao Mengmeng <zhaomengmeng@kylinos.cn>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
 tools/sched_ext/include/scx/compat.bpf.h | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/tools/sched_ext/include/scx/compat.bpf.h b/tools/sched_ext/include/scx/compat.bpf.h
index 654b566bd94a..8977b5a2caa1 100644
--- a/tools/sched_ext/include/scx/compat.bpf.h
+++ b/tools/sched_ext/include/scx/compat.bpf.h
@@ -422,11 +422,6 @@ static inline void scx_bpf_dsq_reenq(u64 dsq_id, u64 reenq_flags)
 		scx_bpf_error("kernel too old to reenqueue foreign local or user DSQs");
 }
 
-/*
- * v7.1: %SCX_ENQ_IMMED.
- */
-#define SCX_ENQ_IMMED	__COMPAT_ENUM_OR_ZERO(enum scx_enq_flags, SCX_ENQ_IMMED)
-
 /*
  * Define sched_ext_ops. This may be expanded to define multiple variants for
  * backward compatibility. See compat.h::SCX_OPS_LOAD/ATTACH().
-- 
2.53.0

Applied to sched_ext/for-7.1.

Thanks.

--
tejun