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authorIngo Molnar <mingo@kernel.org>2024-01-26 10:26:50 +0100
committerIngo Molnar <mingo@kernel.org>2024-01-26 10:26:50 +0100
commit42ac0be18bfa09c03f52244f7c3e15c89b38532f (patch)
tree601fd5e6da2ca0b77aa8cb22f0e81a29ba6fe1d6 /tools/testing/selftests/bpf/progs/pyperf180.c
parent8e5647a723c49d73b9f108a8bb38e8c29d3948ea (diff)
parentecb1b8288dc7ccbdcb3b9df005fa1c0e0c0388a7 (diff)
Merge branch 'linus' into x86/mm, to refresh the branch and pick up fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'tools/testing/selftests/bpf/progs/pyperf180.c')
-rw-r--r--tools/testing/selftests/bpf/progs/pyperf180.c22
1 files changed, 22 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/pyperf180.c b/tools/testing/selftests/bpf/progs/pyperf180.c
index c39f559d3100..42c4a8b62e36 100644
--- a/tools/testing/selftests/bpf/progs/pyperf180.c
+++ b/tools/testing/selftests/bpf/progs/pyperf180.c
@@ -1,4 +1,26 @@
// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2019 Facebook
#define STACK_MAX_LEN 180
+
+/* llvm upstream commit at clang18
+ * https://github.com/llvm/llvm-project/commit/1a2e77cf9e11dbf56b5720c607313a566eebb16e
+ * changed inlining behavior and caused compilation failure as some branch
+ * target distance exceeded 16bit representation which is the maximum for
+ * cpu v1/v2/v3. Macro __BPF_CPU_VERSION__ is later implemented in clang18
+ * to specify which cpu version is used for compilation. So a smaller
+ * unroll_count can be set if __BPF_CPU_VERSION__ is less than 4, which
+ * reduced some branch target distances and resolved the compilation failure.
+ *
+ * To capture the case where a developer/ci uses clang18 but the corresponding
+ * repo checkpoint does not have __BPF_CPU_VERSION__, a smaller unroll_count
+ * will be set as well to prevent potential compilation failures.
+ */
+#ifdef __BPF_CPU_VERSION__
+#if __BPF_CPU_VERSION__ < 4
+#define UNROLL_COUNT 90
+#endif
+#elif __clang_major__ == 18
+#define UNROLL_COUNT 90
+#endif
+
#include "pyperf.h"