Messages in this thread | | | From | Sumit Garg <> | Date | Mon, 18 May 2020 19:39:23 +0530 | Subject | Re: [PATCH 0/3] arm64: perf: Add support for Perf NMI interrupts |
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On Mon, 18 May 2020 at 16:47, Alexandru Elisei <alexandru.elisei@arm.com> 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. >
Thanks Mark, Alex for the status updates on perf NMI feature.
Alex,
As the hard-lockup detection patch [1] has a dependency on perf NMI patch-set, I will rebase and test hard-lockup detector when you have got a working tree. But due to the dependency, I think patch [1] should be accepted along with perf NMI patch-set. So would you be open to include this patch as part of your series?
[1] http://lists.infradead.org/pipermail/linux-arm-kernel/2020-May/732227.html
-Sumit
> 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
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