On 06/06/2013 09:33 AM, Michael Ellerman wrote: > In commit 59affcd I added context switching of more PMU SPRs, because > they are potentially exposed to userspace on Power8. However despite me > being a smart arse in the commit message it's actually not correct. In > particular it interacts badly with a global perf record.
Could you please explain how it would interact badly with a global perf record. If any user space try to mess around with the MMCR* registers itself, it would definitely interfere with the kernel's own PMU config going on during perf record. But thats how it works. So when we are actually dealing with MMCR* registers directly, we should not invoke "perf record" session which can potential run on the same PMU. Regards Anshuman _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
