On 28 August 2016 at 16:00, Madhavan Srinivasan <ma...@linux.vnet.ibm.com> wrote: > Patchset to extend PERF_SAMPLE_REGS_INTR to include > platform specific PMU registers. > > Patchset applies cleanly on tip:perf/core branch > > It's a perennial request from hardware folks to be able to > see the raw values of the pmu registers. Partly it's so that > they can verify perf is doing what they want, and some > of it is that they're interested in some of the more obscure > info that isn't plumbed out through other perf interfaces. > > Over the years internally we have used various hack to get > the requested data out but this is an attempt to use a > somewhat standard mechanism (using PERF_SAMPLE_REGS_INTR). > > This would also be helpful for those of us working on the perf > hardware backends, to be able to verify that we're programming > things correctly, without resorting to debug printks etc. > > Mechanism proposed: > > 1)perf_regs structure is extended with a perf_arch_regs structure > which each arch/ can populate with their specific platform > registers to sample on each perf interrupt and an arch_regs_mask > variable, which is for perf tool to know about the perf_arch_regs > that are supported. > > 2)perf/core func perf_sample_regs_intr() extended to update > the perf_arch_regs structure and the perf_arch_reg_mask. Set of new > support functions added perf_get_arch_regs_mask() and > perf_get_arch_reg() to aid the updates from arch/ side. > > 3) perf/core funcs perf_prepare_sample() and perf_output_sample() > are extended to support the update for the perf_arch_regs_mask and > perf_arch_regs in the sample > > 4)perf/core func perf_output_sample_regs() extended to dump > the arch_regs to the output sample. > > 5)Finally, perf tool side is updated to include a new element > "arch_regs_mask" in the "struct regs_dump", event sample funcs > and print functions are updated to support perf_arch_regs. >
I read the patch series and I have one suggestion to make. I think we should not use 'arch regs' to refer to these pmu registers. I think architectural registers typically refer to the ones that hold the state of the process. Can we replace arch_regs by pmu_regs, or some other choice? Thanks Nilay
