| Arnaldo Carvalho de Melo | 00204c3 | 2010-10-26 17:07:33 -0200 | [diff] [blame] | 1 | # futex contention |
| 2 | # (c) 2010, Arnaldo Carvalho de Melo <acme@redhat.com> |
| 3 | # Licensed under the terms of the GNU GPL License version 2 |
| 4 | # |
| 5 | # Translation of: |
| 6 | # |
| 7 | # http://sourceware.org/systemtap/wiki/WSFutexContention |
| 8 | # |
| 9 | # to perf python scripting. |
| 10 | # |
| 11 | # Measures futex contention |
| 12 | |
| 13 | import os, sys |
| 14 | sys.path.append(os.environ['PERF_EXEC_PATH'] + '/scripts/python/Perf-Trace-Util/lib/Perf/Trace') |
| 15 | from Util import * |
| 16 | |
| 17 | process_names = {} |
| 18 | thread_thislock = {} |
| 19 | thread_blocktime = {} |
| 20 | |
| 21 | lock_waits = {} # long-lived stats on (tid,lock) blockage elapsed time |
| 22 | process_names = {} # long-lived pid-to-execname mapping |
| 23 | |
| 24 | def syscalls__sys_enter_futex(event, ctxt, cpu, s, ns, tid, comm, |
| 25 | nr, uaddr, op, val, utime, uaddr2, val3): |
| 26 | cmd = op & FUTEX_CMD_MASK |
| 27 | if cmd != FUTEX_WAIT: |
| 28 | return # we don't care about originators of WAKE events |
| 29 | |
| 30 | process_names[tid] = comm |
| 31 | thread_thislock[tid] = uaddr |
| 32 | thread_blocktime[tid] = nsecs(s, ns) |
| 33 | |
| 34 | def syscalls__sys_exit_futex(event, ctxt, cpu, s, ns, tid, comm, |
| 35 | nr, ret): |
| 36 | if thread_blocktime.has_key(tid): |
| 37 | elapsed = nsecs(s, ns) - thread_blocktime[tid] |
| 38 | add_stats(lock_waits, (tid, thread_thislock[tid]), elapsed) |
| 39 | del thread_blocktime[tid] |
| 40 | del thread_thislock[tid] |
| 41 | |
| 42 | def trace_begin(): |
| 43 | print "Press control+C to stop and show the summary" |
| 44 | |
| 45 | def trace_end(): |
| 46 | for (tid, lock) in lock_waits: |
| 47 | min, max, avg, count = lock_waits[tid, lock] |
| 48 | print "%s[%d] lock %x contended %d times, %d avg ns" % \ |
| 49 | (process_names[tid], tid, lock, count, avg) |
| 50 | |