1 files changed, 50 insertions, 0 deletions

diff --git a/tools/perf/scripts/python/futex-contention.py b/tools/perf/scripts/python/futex-contention.py
new file mode 100644
index 00000000000..11e70a388d4
--- /dev/null
+++ b/tools/perf/scripts/python/futex-contention.py
@@ -0,0 +1,50 @@
+# futex contention
+# (c) 2010, Arnaldo Carvalho de Melo <acme@redhat.com>
+# Licensed under the terms of the GNU GPL License version 2
+#
+# Translation of:
+#
+# http://sourceware.org/systemtap/wiki/WSFutexContention
+#
+# to perf python scripting.
+#
+# Measures futex contention
+
+import os, sys
+sys.path.append(os.environ['PERF_EXEC_PATH'] + '/scripts/python/Perf-Trace-Util/lib/Perf/Trace')
+from Util import *
+
+process_names = {}
+thread_thislock = {}
+thread_blocktime = {}
+
+lock_waits = {} # long-lived stats on (tid,lock) blockage elapsed time
+process_names = {} # long-lived pid-to-execname mapping
+
+def syscalls__sys_enter_futex(event, ctxt, cpu, s, ns, tid, comm,
+                              nr, uaddr, op, val, utime, uaddr2, val3):
+        cmd = op & FUTEX_CMD_MASK
+        if cmd != FUTEX_WAIT:
+                return # we don't care about originators of WAKE events
+
+        process_names[tid] = comm
+        thread_thislock[tid] = uaddr
+        thread_blocktime[tid] = nsecs(s, ns)
+
+def syscalls__sys_exit_futex(event, ctxt, cpu, s, ns, tid, comm,
+                             nr, ret):
+        if thread_blocktime.has_key(tid):
+                elapsed = nsecs(s, ns) - thread_blocktime[tid]
+                add_stats(lock_waits, (tid, thread_thislock[tid]), elapsed)
+                del thread_blocktime[tid]
+                del thread_thislock[tid]
+
+def trace_begin():
+        print "Press control+C to stop and show the summary"
+
+def trace_end():
+        for (tid, lock) in lock_waits:
+                min, max, avg, count = lock_waits[tid, lock]
+                print "%s[%d] lock %x contended %d times, %d avg ns" % \
+                      (process_names[tid], tid, lock, count, avg)
+