There is indeed something wrong. Avi Goren: > Hi, > I'm using lttng-ust and in the process of the attempt to gain some flush > frequency control I encountered a problem. > I'm having difficulties with the use of enable-channel. > it doesn't seem to apply property changes. here's an example: > ------------------------------------------------------------------------- > root@ubuntu:~# lttng list > Currently no available tracing session > root@ubuntu:~# lttng create ses > Session ses created. > Traces will be written in /home/avig/lttng-traces/ses-20130624-163340 > root@ubuntu:~# lttng enable-event -a -u -s ses -c ch > All UST events are enabled in channel ch
This command creates and enables all event in the channel "ch" with the default settings for the channel. > root@ubuntu:~# lttng disable-channel ch -u -s ses > UST channel ch disabled for session ses > root@ubuntu:~# lttng enable-channel ch -u --subbuf-size 1024 --num-subbuf 1 > UST channel ch enabled for session ses This command actually only enable the *already* existing channel. Once a channel is created, you can't change the attributes, it's immutable. > root@ubuntu:~# lttng list ses -c ch > Tracing session ses: [inactive] > Trace path: /home/avig/lttng-traces/ses-20130624-163340 > > === Domain: UST global === > > Buffer type: per PID > > - ch: [enabled] > > Attributes: > write mode: discard > subbufers size: 4096 bytes > number of subbufers: 4 > switch timer interval: 0 usec > read timer interval: 0 usec > output: mmap() > > Events: > * (type: tracepoint) [enabled] > > root@ubuntu:~# lttng version > lttng version 2.2.0-rc2 - Cuda > ... > ------------------------------------------------------------------------- > > Am I doing something wrong? > Is there a way to control flushing policy besides the use of enable-channel? If you want to control the flushing timing of a channel, use "--switch-timer". For instance, for a flush buffer at each 200ms: $ lttng enable-channel ch -u --switch timer 200000 Hope this can help! David > Thanks, > Avi > > > This body part will be downloaded on demand. _______________________________________________ lttng-dev mailing list [email protected] http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
