From: Ingo Molnar <mingo@xxxxxxx> Date: Fri, 5 Dec 2008 07:10:12 +0100 > * David Miller <davem@xxxxxxxxxxxxx> wrote: > > > From: Thomas Gleixner <tglx@xxxxxxxxxxxxx> > > Date: Thu, 04 Dec 2008 23:44:39 -0000 > > > > > - No interaction with ptrace: any task (with sufficient permissions) can > > > monitor other tasks, without having to stop that task. > > > > This isn't going to work. > > > > If you look at the things the perfmon libraries do, you do need to stop > > the task. > > > > Consider counter virtualization as the most direct example. [...] > > Note that counter virtualization is not offered in the perfmon3 patchset > that has been posted to lkml. (It is part of the much larger 'full' > perfmon patchset which has not been submitted for integration) I know, it was yanked out to make a merge more likely. > Relying on ptrace machinery can be considered one of the bigger design > mistakes of the permon3 patchset. I totally disagree. > We pointed that out in review, and now we demonstrate it via this > patchset that it can be done much cleaner and much simpler. (Please stay > tuned for -v2 if you want to see the proof of the pudding.) I hope it will provide enough for full PAPI library support, otherwise it's useless for most of the world. -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
