On Fri, Oct 11, 2013 at 10:02:28AM +0530, Anshuman Khandual wrote: > On 10/11/2013 07:41 AM, Michael Ellerman wrote: > > On Thu, Oct 10, 2013 at 02:20:22PM +0530, Anshuman Khandual wrote: > > > >> Even I think this is not right. Instruction sampling should have been > >> enabled before we enable PMU interrupts. Else there is a small window > >> of time where we could have the PMU enabled with events (which requires > >> sampling) without the sampling itself being enabled in MMCRA. > > > > Yes I agree. That's a separate bug, which we'll need to test on all the > > book3s > > platforms we have perf support for. > > Okay, I guess any platform which supports sampling will definitely want to > have > it enabled before we can set the events to count on PMU. Can you think of any > problem which can arise if we move it before the enabling the PMU back ? Else > we can fix this easily.
In theory it should be a trivial change. But hardware can behave in strange ways, it's possible on some old chip we need to do it the current way for some reason. So although I don't think it will be a problem, it could be, so we will need to test it thoroughly. cheers _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
