| # 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) |
| |