Documentation/trace/histogram.rst

1701 creates a variable named 'ts0' for a histogram entry with the key
1704   # echo 'hist:keys=next_pid:vals=$ts0:ts0=common_timestamp ... >> \
1707 The ts0 variable can be accessed by any subsequent event having the
1711 the '$' sign.  Thus for example, the ts0 variable above would be
1712 referenced as '$ts0' in expressions.
1729 result in both ts0 and b being created as variables, with both
1732   # echo 'hist:keys=pid:vals=$ts0,$b:ts0=common_timestamp,b=field1 ...' >> \
1739   # echo 'hist:keys=pid:ts0=common_timestamp,b=field1:vals=$ts0,$b ...' >> \
1746   # echo 'hist:keys=pid:ts0=common_timestamp:b=field1 ...' >> event/trigger
1753   # echo 'hist:keys=pid,prio:ts0=common_timestamp ...' >> event1/trigger
1754   # echo 'hist:keys=next_pid:wakeup_lat=common_timestamp-$ts0 ...' >> event2/trigger
1757 variable ts0.  In the next line, ts0 is subtracted from the second
1983     cyclictest thread, save the timestamp in a 'ts0' variable::
1985       # echo 'hist:keys=$saved_pid:saved_pid=pid:ts0=common_timestamp.usecs \
1994       # echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:\
2033       # echo 'hist:keys=pid:ts0=common_timestamp.usecs \
2038               wakeup_lat=common_timestamp.usecs-$ts0:\
2049           common_timestamp-ts0:          0
2055           common_timestamp-ts0: 0
2095     # echo 'hist:keys=pid:ts0=common_timestamp.usecs \
2099     # echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0: \
2301 …# echo 'hist:keys=common_pid:ts0=common_timestamp.usecs if buf == "start"' > events/ftrace/print/t…
2302 …# echo 'hist:keys=common_pid:lat=common_timestamp.usecs-$ts0:onmatch(ftrace.print).latency($lat) i…
2632  # echo 'hist:keys=pid:ts0=common_timestamp.usecs' > events/sched/sched_waking/trigger
2633 …# echo 'hist:keys=common_pid:lat=common_timestamp.usecs-$ts0:onmatch(sched.sched_waking).latency($…