From: Zhao Mengmeng <[email protected]> When compiling sched_ext selftests using clang 17.0.6, it raised compiler crash and build error:
Error at line 68: Unsupport signed division for DAG: 0x55b2f9a60240: i64 = sdiv 0x55b2f9a609b0, Constant:i64<100>, peek_dsq.bpf.c:68:25 @[ peek_dsq.bpf.c:95:4 @[ peek_dsq.bpf.c:169:8 @[ peek _dsq.bpf.c:140:6 ] ] ]Please convert to unsigned div/mod After digging, it's not a compiler error, clang supported Signed division only when using -mcpu=v4, while we use -mcpu=v3 currently, the better way is to use unsigned div, see [1] for details. [1] https://github.com/llvm/llvm-project/issues/70433 Signed-off-by: Zhao Mengmeng <[email protected]> --- tools/testing/selftests/sched_ext/peek_dsq.bpf.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/sched_ext/peek_dsq.bpf.c b/tools/testing/selftests/sched_ext/peek_dsq.bpf.c index a3faf5bb49d6..784f2f6c1af9 100644 --- a/tools/testing/selftests/sched_ext/peek_dsq.bpf.c +++ b/tools/testing/selftests/sched_ext/peek_dsq.bpf.c @@ -58,14 +58,14 @@ static void record_peek_result(long pid) { u32 slot_key; long *slot_pid_ptr; - int ix; + u32 ix; if (pid <= 0) return; /* Find an empty slot or one with the same PID */ bpf_for(ix, 0, 10) { - slot_key = (pid + ix) % MAX_SAMPLES; + slot_key = ((u64)pid + ix) % MAX_SAMPLES; slot_pid_ptr = bpf_map_lookup_elem(&peek_results, &slot_key); if (!slot_pid_ptr) continue; -- 2.43.0
