# futex contention # (c) 2010, Arnaldo Carvalho de Melo # 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, 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 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) ref='/cgit.cgi/linux/net-next.git/refs/?id=4d1ceea8516cd6adf21f6b75995e2a7d4f376f9b'>refslog tree commit diff

path: root/net/sched/sch_gred.c

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