Messages in this thread | | | Subject | Re: [PATCH 0/3] arm64: perf: Add support for Perf NMI interrupts | From | Alexandru Elisei <> | Date | Thu, 21 May 2020 13:36:06 +0100 |
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Hi,
On 5/21/20 4:00 AM, Song Bao Hua (Barry Song) wrote:
> >> -----Original Message----- >> From: linux-arm-kernel [mailto:linux-arm-kernel-bounces@lists.infradead.org] >> On Behalf Of Alexandru Elisei >> Sent: Wednesday, May 20, 2020 10:31 PM> >> 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-pm >> u-nmi > Fortunately, it does work. I used this tree to perf annotate arm_smmu_cmdq_issue_cmdlist() which > is completely disabling IRQ. Luckily, it reports correct data. Before that, it reported all time was spent by > the code which enabled IRQ .
That's good news that it works for you, thanks for letting me know.
Alex
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