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, Alex > > Thanks, > Mark. > >> This is really useful in debugging. >> Thank you!! >> >> >> >> [1] https://lkml.org/lkml/2020/4/24/328 >> >> >> Lecopzer >> >> Sumit Garg <sumit.g...@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 <lecop...@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-ker...@lists.infradead.org >>>> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
