Messages in this thread | | | Date | Mon, 18 May 2020 11:45:24 +0100 | From | Mark Rutland <> | Subject | Re: [PATCH 0/3] arm64: perf: Add support for Perf NMI interrupts |
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Hi all,
On Mon, May 18, 2020 at 02:26:00PM +0800, Lecopzer Chen wrote: > HI Sumit, > > Thanks for your information. > > I've already implemented IPI (same as you did [1], little difference > in detail), hardlockup detector and perf in last year(2019) for > debuggability. > And now we tend to upstream to reduce kernel maintaining effort. > I'm glad if someone in ARM can do this work :) > > Hi Julien, > > Does any Arm maintainers can proceed this action?
Alexandru (Cc'd) has been rebasing and reworking Julien's patches, which is my preferred approach.
I understand that's not quite ready for posting since he's investigating some of the nastier subtleties (e.g. mutual exclusion with the NMI), but maybe we can put the work-in-progress patches somewhere in the mean time.
Alexandru, do you have an idea of what needs to be done, and/or when you expect you could post that?
Thanks, Mark.
> This is really useful in debugging. > Thank you!! > > > > [1] https://lkml.org/lkml/2020/4/24/328 > > > Lecopzer > > Sumit Garg <sumit.garg@linaro.org> 於 2020年5月18日 週一 下午1:46寫道: > > > > + Julien > > > > Hi Lecopzer, > > > > On Sat, 16 May 2020 at 18:20, Lecopzer Chen <lecopzer@gmail.com> wrote: > > > > > > These series implement Perf NMI funxtionality and depends on > > > Pseudo NMI [1] which has been upstreamed. > > > > > > In arm64 with GICv3, Pseudo NMI was implemented for NMI-like interruts. > > > That can be extended to Perf NMI which is the prerequisite for hard-lockup > > > detector which had already a standard interface inside Linux. > > > > > > Thus the first step we need to implement perf NMI interface and make sure > > > it works fine. > > > > > > > This is something that is already implemented via Julien's patch-set > > [1]. Its v4 has been floating since July, 2019 and I couldn't find any > > major blocking comments but not sure why things haven't progressed > > further. > > > > Maybe Julien or Arm maintainers can provide updates on existing > > patch-set [1] and how we should proceed further with this interesting > > feature. > > > > And regarding hard-lockup detection, I have been able to enable it > > based on perf NMI events using Julien's perf patch-set [1]. Have a > > look at the patch here [2]. > > > > [1] https://patchwork.kernel.org/cover/11047407/ > > [2] http://lists.infradead.org/pipermail/linux-arm-kernel/2020-May/732227.html > > > > -Sumit > > > > > Perf NMI has been test by dd if=/dev/urandom of=/dev/null like the link [2] > > > did. > > > > > > [1] https://lkml.org/lkml/2019/1/31/535 > > > [2] https://www.linaro.org/blog/debugging-arm-kernels-using-nmifiq > > > > > > > > > Lecopzer Chen (3): > > > arm_pmu: Add support for perf NMI interrupts registration > > > arm64: perf: Support NMI context for perf event ISR > > > arm64: Kconfig: Add support for the Perf NMI > > > > > > arch/arm64/Kconfig | 10 +++++++ > > > arch/arm64/kernel/perf_event.c | 36 ++++++++++++++++++------ > > > drivers/perf/arm_pmu.c | 51 ++++++++++++++++++++++++++++++---- > > > include/linux/perf/arm_pmu.h | 6 ++++ > > > 4 files changed, 88 insertions(+), 15 deletions(-) > > > > > > -- > > > 2.25.1 > > > > > > > > > _______________________________________________ > > > linux-arm-kernel mailing list > > > linux-arm-kernel@lists.infradead.org > > > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
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