Messages in this thread | | | Subject | Re: [PATCH 0/3] arm64: perf: Add support for Perf NMI interrupts | From | Alexandru Elisei <> | Date | Wed, 20 May 2020 11:30:45 +0100 |
| |
Hi,
On 5/18/20 12:17 PM, Alexandru Elisei wrote: > Hi, > > On 5/18/20 11:45 AM, Mark Rutland wrote: >> 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? > I'm currently working on rebasing the patches on top of 5.7-rc5, when I have > something usable I'll post a link (should be a couple of days). After that I will > address the review comments, and I plan to do a thorough testing because I'm not > 100% confident that some of the assumptions around the locks that were removed are > correct. My guess is this will take a few weeks.
Pushed a WIP branch on linux-arm.org [1]:
git clone -b WIP-pmu-nmi git://linux-arm.org/linux-ae
Practically untested, I only did perf record on a defconfig kernel running on the model.
[1] http://www.linux-arm.org/git?p=linux-ae.git;a=shortlog;h=refs/heads/WIP-pmu-nmi
Thanks, Alex > > Thanks, > Alex >> 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 > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
| |