On 10/14/2013 11:49 AM, Michael Ellerman wrote: > 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.
So which are the HW chips, you would like to test this fix for possible problems ? _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
