Android: uses settask to enable CPU affinity for ADB.

build/android/bb_run_sharded_steps.py

Index: build/android/bb_run_sharded_steps.py
diff --git a/build/android/bb_run_sharded_steps.py b/build/android/bb_run_sharded_steps.py
index 086a3a13e3154c9858ba6ff6178e72ffedf9f88d..628f7be6f3c7ccb658338c86c5497a20e9b148c0 100755
--- a/build/android/bb_run_sharded_steps.py
+++ b/build/android/bb_run_sharded_steps.py
@@ -175,11 +175,9 @@ def _KillPendingServers():
           os.kill(int(pid), signal.SIGQUIT)
         except Exception as e:
           logging.warning('Failed killing %s %s %s', server, pid, e)
-  # Restart the adb server with full trace, and redirect stderr to stdout
-  # so the extra tracing won't confuse higher up layers.
-  os.environ['ADB_TRACE'] = 'all'
+  # Restart the adb server with taskset to set a single CPU affinity.
   cmd_helper.RunCmd(['adb', 'kill-server'])
-  cmd_helper.RunCmd(['adb', 'start-server'])
+  cmd_helper.RunCmd(['taskset', '-c', '1', 'adb', 'start-server'])

[frankf, 2013/08/08 21:38:09]

why not -c 0?

[bulach, 2013/08/09 09:15:47]

my bad, I was confused by "man taskset": it says for mask, 0x00000001 is the CPU
#0... that's not the case for -c, thanks for pointing out.

   cmd_helper.RunCmd(['adb', 'root'])
   i = 1
   while not android_commands.GetAttachedDevices():