summaryrefslogtreecommitdiffstats
path: root/tools/perf/scripts/python/futex-contention.py
diff options
context:
space:
mode:
Diffstat (limited to 'tools/perf/scripts/python/futex-contention.py')
-rw-r--r--tools/perf/scripts/python/futex-contention.py57
1 files changed, 57 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 000000000..7e884d46f
--- /dev/null
+++ b/tools/perf/scripts/python/futex-contention.py
@@ -0,0 +1,57 @@
+# 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
+
+from __future__ import print_function
+
+import os
+import 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, callchain,
+ 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, callchain,
+ nr, ret):
+ if tid in thread_blocktime:
+ 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 [max: %d ns, min %d ns]" %
+ (process_names[tid], tid, lock, count, avg, max, min))