On Thu, Oct 22, 2020 at 03:20:33PM -0600, Mathieu Poirier wrote:
Suzuki's depiction of the usecase is accurate. Using the pid of the process that created the events comes out of a discussion you and I had in the common area by the Intel booth at ELC in Edinburgh in the fall of 2018. At the time I exposed the problem of having multiple events sharing the same HW resources and you advised to proceed this way.
Bah, I was afraid of that. I desperately tried to find correspondence on it, but alas, verbal crap doesn't end up in the Sent folder :-/
That being said it is plausible that I did not expressed myself clearly enough for you to understand the full extend of the problem. If that is the case we are more than willing to revisit that solution. Do you see a better option than what has currently been implemented?
Moo... that really could've done with a comment I suppose.
So then I don't understand the !->owner issue, that only happens when the task dies, which cannot be concurrent with event creation. Are you somehow accessing ->owner later?
As for the kernel events.. why do you care about the actual task_struct * in there? I see you're using it to grab the task-pid, but how is that useful?