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* tracing: Document trace_marker triggersSteven Rostedt (VMware)2018-05-291-1/+544
| | | | | | | | Add documentation and an example on how to use trace_marker triggers. Reviewed-by: Tom Zanussi <tom.zanussi@linux.intel.com> Reviewed-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
* tracing: Add a clock attribute for hist triggersTom Zanussi2018-03-101-1/+10
| | | | | | | | | | | | | | The default clock if timestamps are used in a histogram is "global". If timestamps aren't used, the clock is irrelevant. Use the "clock=" param only if you want to override the default "global" clock for a histogram with timestamps. Link: http://lkml.kernel.org/r/427bed1389c5d22aa40c3e0683e30cc3d151e260.1516069914.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> Signed-off-by: Rajvi Jingar <rajvi.jingar@intel.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
* tracing: Add inter-event hist trigger DocumentationTom Zanussi2018-03-101-0/+381
| | | | | | | | | | | Add background and details on inter-event hist triggers, including hist variables, synthetic events, and actions. Link: http://lkml.kernel.org/r/b0414efb66535aa52aa7411f58c3d56724027fce.1516069914.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> Signed-off-by: Baohong Liu <baohong.liu@intel.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
* tracing: Add 'last error' error facility for hist triggersTom Zanussi2018-03-101-0/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | With the addition of variables and actions, it's become necessary to provide more detailed error information to users about syntax errors. Add a 'last error' facility accessible via the erroring event's 'hist' file. Reading the hist file after an error will display more detailed information about what went wrong, if information is available. This extended error information will be available until the next hist trigger command for that event. # echo xxx > /sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger echo: write error: Invalid argument # cat /sys/kernel/debug/tracing/events/sched/sched_wakeup/hist ERROR: Couldn't yyy: zzz Last command: xxx Also add specific error messages for variable and action errors. Link: http://lkml.kernel.org/r/64e9c422fc8aeafcc2f7a3b4328c0cffe7969129.1516069914.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
* tracing: Add cpu field for hist triggersTom Zanussi2018-03-101-0/+15
| | | | | | | | | | A common key to use in a histogram is the cpuid - add a new cpu 'synthetic' field named 'cpu' for that purpose. Link: http://lkml.kernel.org/r/89537645bfc957e0d76e2cacf5f0ada88691a6cc.1516069914.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
* tracing: Add usecs modifier for hist trigger timestampsTom Zanussi2018-03-101-0/+1
| | | | | | | | | | | | | | | | | | Appending .usecs onto a common_timestamp field will cause the timestamp value to be in microseconds instead of the default nanoseconds. A typical latency histogram using usecs would look like this: # echo 'hist:keys=pid,prio:ts0=common_timestamp.usecs ... # echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0 ... This also adds an external trace_clock_in_ns() to trace.c for the timestamp conversion. Link: http://lkml.kernel.org/r/4e813705a170b3e13e97dc3135047362fb1a39f3.1516069914.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
* tracing: Add Documentation for log2 modifierTom Zanussi2018-03-101-0/+1
| | | | | | | | | | Add a line for the log2 modifier, to keep it aligned with tracing/README. Link: http://lkml.kernel.org/r/a419028bccab155749a4b8702d5b97af75f1578f.1516069914.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
* tracing: Move hist trigger Documentation to histogram.txtTom Zanussi2018-03-101-0/+1568
The hist trigger Documentation takes up a large part of events.txt - since it will be getting even larger, move it to a separate file. Link: http://lkml.kernel.org/r/92761155ea4f529e590821b1e02207fe8619f248.1516069914.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>