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Diffstat (limited to '')
-rw-r--r-- | tools/perf/scripts/python/futex-contention.py | 57 |
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)) |