2016-08-19 18:22, Jerin Jacob: > On Fri, Aug 19, 2016 at 02:24:58PM +0200, Jan Viktorin wrote: > > On Fri, 19 Aug 2016 17:16:12 +0530 > > Jerin Jacob <jerin.jacob at caviumnetworks.com> wrote: > > > > > > I've got a private kernel driver enabling and disabling (hopefully) properly > > this for ARMv7. If we'd like to merge it, I'd like to have a single module > > or at least single module with 2 implementations... > > > > I can post it if it would be helpful. > > I don't think we can use this in production as this may alter PMU state used > by 'perf' etc.I think let it be a debug interface for armv7 and armv8 > and disable it by default.
Please could you document the use of PMU for debug and how it alters usage of kernel counters? A patch in doc/guides/prog_guide/profile_app.rst would be welcome. Ideally, it would be a lot better to have a sysfs entry to enable PMU counter with an upstream kernel.
