On Tue, Apr 03, 2018 at 03:45:17PM -0700, Palmer Dabbelt wrote: > On Tue, 03 Apr 2018 07:29:02 PDT (-0700), alan...@andestech.com wrote: > >On Mon, Apr 02, 2018 at 08:15:44PM -0700, Palmer Dabbelt wrote: > >>On Mon, 02 Apr 2018 05:31:22 PDT (-0700), alan...@andestech.com wrote: > >>>This implements the baseline PMU for RISC-V platforms. > >>> > >>>To ease future PMU portings, a guide is also written, containing > >>>perf concepts, arch porting practices and some hints. > >>> > >>>Changes in v2: > >>> - Fix the bug reported by Alex, which was caused by not sufficient > >>> initialization. Check https://lkml.org/lkml/2018/3/31/251 for the > >>> discussion. > >>> > >>>Alan Kao (2): > >>> perf: riscv: preliminary RISC-V support > >>> perf: riscv: Add Document for Future Porting Guide > >>> > >>> Documentation/riscv/pmu.txt | 249 +++++++++++++++++++ > >>> arch/riscv/Kconfig | 12 + > >>> arch/riscv/include/asm/perf_event.h | 76 +++++- > >>> arch/riscv/kernel/Makefile | 1 + > >>> arch/riscv/kernel/perf_event.c | 468 > >>> ++++++++++++++++++++++++++++++++++++ > >>> 5 files changed, 802 insertions(+), 4 deletions(-) > >>> create mode 100644 Documentation/riscv/pmu.txt > >>> create mode 100644 arch/riscv/kernel/perf_event.c > >> > >>I'm having some trouble pulling this into my tree. I think you might have > >>another patch floating around somewhere, as I don't have any > >>arch/riscv/include/asm/perf_event.h right now. > >> > >>Do you mind rebasing this on top of linux-4.16 so I can look properly? > >> > >>Thanks! > > > >Sorry for the inconvenience, but this patch was based on Alex's patch at > >https://github.com/riscv/riscv-linux/pull/124/files. I thought that one > >had already been picked into your tree. > > > >Any ideas? > > Thanks, it applies on top of that. I'm going to play around with this a > bit, but it looks generally good.
Note that to make it work better when wraparound occurs, you should change the value of *.counter_width* into the width of real hardware counters. This is because this patch does not handle wraparound checking, so using a wider bit mask may sometimes report a extremely large number. Ideally this should be done by adding a Kconfig option called "Hifive Unleashed PMU" which automatically sets the width an reuses most of the baseline codes. What do you think about this? Thanks. -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html