[lttng-dev] Enabling and disabling events

Ikaheimonen, JP jp_ikaheimonen at mentor.com
Wed Sep 11 08:22:13 EDT 2013

Hi Daniel,

I can see your point about how the events are created. I do not completely agree with your views, but it is not essential that I do.

How about the following (this is based on the ideas you have brought forth):

We keep the enable-event command as it is. However, we enhance the event name specification syntax somewhat. We could of course do a full regex matching, but I fear that would get too slow.  Instead we'd have something like

$ lttng enable-event -u "*!mine*!alsomine"

This would enable any event ('*'), except those who match with mine* or alsomine.

The matching logic would separate the name specification into parts, using the ! character as a separator. If the new event name matches the first part but does not match any of the latter parts, then the event gets enabled.

I don't like collating the event enablers into unified specifications. I'd like to have each enable-event command create its own entries into the enabler list. I feel a bit uneasy if the event enabler code gets too sophisticated.

I'm still unsure how the disable-event command should work. I'm playing around with the idea that the event specification in the disable-event command should exactly match the event specification given in the enable-event command. It does not feel good, but any solution around it seems to bring about the ideas about disable-lists which I would like to avoid.

JP Ikaheimonen | SW Development Engineer http://go.mentor.com/sourceryanalyzer

Mentor Embedded(tm) | Nucleus(r) | Linux(r) | Android(tm) | Services | UI | Multi-OS

Android is a trademark of Google Inc. Use of this trademark is subject to Google Permissions.
Linux is the registered trademark of Linus Torvalds in the U.S. and other countries.

More information about the lttng-dev mailing list