[OrderFiles] Don't allow lit to run dtrace multithreaded

Dtrace is implemented to try and minimize performance impact on the process being traced. This results in dtrace dropping samples if it is taking too many CPU resources. Multi-threading dtrace increases the sample drop rate dramatically.

llvm-svn: 266213

diff --git a/clang/utils/perf-training/CMakeLists.txt b/clang/utils/perf-training/CMakeLists.txt
index f8647a0..07d9024 100644 (file)
--- a/clang/utils/perf-training/CMakeLists.txt
+++ b/clang/utils/perf-training/CMakeLists.txt
@@ -48,6 +48,7 @@ if(DTRACE)
 
   add_lit_testsuite(generate-dtrace-logs "Generating clang dtrace data"
     ${CMAKE_CURRENT_BINARY_DIR}/order-files/
+    ARGS -j 1
     DEPENDS clang clear-dtrace-logs
     )