Revert "[ci] Start capture process earlier to reduce benchmark repeti…

…tions"

build_tools/benchmarks/common/benchmark_definition.py

@@ -183,12 +183,14 @@ def get_iree_benchmark_module_arguments(
 ):
     """Returns the common arguments to run iree-benchmark-module."""
 
-    if capture_mode:
-        repetitions = 1
-    elif driver_info.loader_name == "vmvx-module":
+    if driver_info.loader_name == "vmvx-module":
         # VMVX is very unoptimized for now and can take a long time to run.
         # Decrease the repetition for it until it's reasonably fast.
         repetitions = 3
+    elif capture_mode:
+        # Capture mode is slower and we just need enough repetition to collect
+        # trace after the warmup phase.
+        repetitions = 4
     else:
         repetitions = 10
 

build_tools/benchmarks/run_benchmarks_on_linux.py

@@ -19,7 +19,6 @@
 import shutil
 import subprocess
 import tarfile
-import time
 
 from common import benchmark_suite as benchmark_suite_module
 from common.benchmark_driver import BenchmarkDriver
@@ -236,28 +235,15 @@ def __run_capture(
                 )
             )
 
-        capture_cmd = [capture_config.trace_capture_tool, "-f", "-o", capture_filename]
-        if self.verbose:
-            print(f"cmd: {capture_cmd}")
-        stdout_redirect = None if self.verbose else subprocess.DEVNULL
-
-        # The benchmark process can finish and exit quickly. So start the
-        # capture process first.
-        subprocess.Popen(capture_cmd, stdout=stdout_redirect)
-
-        # Then start the benchmark process and wait for it to stop.
-        execute_cmd(
-            cmd,
-            env={"TRACY_NO_EXIT": "1"},
-            stdout=stdout_redirect,
-            verbose=self.verbose,
+        process = subprocess.Popen(
+            cmd, env={"TRACY_NO_EXIT": "1"}, stdout=subprocess.PIPE, text=True
         )
 
-        # Some extra grace time to let the capture process finish collection.
-        # Note that we will start the next model's benchmarking and capturing
-        # afterwards; so in theory we can overlap here and might not even
-        # need this, but just to be conservative.
-        time.sleep(2)
+        wait_for_iree_benchmark_module_start(process, self.verbose)
+
+        capture_cmd = [capture_config.trace_capture_tool, "-f", "-o", capture_filename]
+        stdout_redirect = None if self.verbose else subprocess.DEVNULL
+        execute_cmd(capture_cmd, verbose=self.verbose, stdout=stdout_redirect)
 
 
 def main(args):