Hi Daniel,
On Thu, 2015-04-30 at 12:06 +0200, Daniel Wagner wrote:
Hi,
I would like to discuss a possible way of getting the feature of the
latecy_hist.patch [1] added to mainline.
"Latency histograms are primarily relevant in the context of real-time
enabled kernels (CONFIG_PREEMPT/CONFIG_PREEMPT_RT)and are used in the
quality management of the Linux real-time capabilities."
Steven pointed out that this might be doable based on Tom Zanussi's
"[PATCH v4 0/7] tracing: 'hist' triggers" [2].
Here are my findings. It was not too complicated to get it working,
though I had to add some hacks. I have added comments to each patch.
It looks like you were able to do quite a bit here with not much code -
nice!
Just FYI, I'll be working on a v5 of the hist triggers patchset that
will incorporate the stuff from patch 1 (needs to be split into a
separate patch for the triggers code already upstream, and one for hist
triggers) and your comments from patch 2 (see comments in my reply to
that patch), along with a couple other unrelated changes...