From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C7C3EC433E0 for ; Thu, 21 May 2020 12:35:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9B2AF2070A for ; Thu, 21 May 2020 12:35:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729350AbgEUMfi (ORCPT ); Thu, 21 May 2020 08:35:38 -0400 Received: from foss.arm.com ([217.140.110.172]:45608 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728133AbgEUMfh (ORCPT ); Thu, 21 May 2020 08:35:37 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 929EF30E; Thu, 21 May 2020 05:35:36 -0700 (PDT) Received: from [192.168.0.110] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 3591B3F305; Thu, 21 May 2020 05:35:34 -0700 (PDT) Subject: Re: [PATCH 0/3] arm64: perf: Add support for Perf NMI interrupts To: "Song Bao Hua (Barry Song)" , Mark Rutland , Lecopzer Chen Cc: Sumit Garg , "jolsa@redhat.com" , Jian-Lin Chen , "alexander.shishkin@linux.intel.com" , Catalin Marinas , "yj.chiang@mediatek.com" , Linux Kernel Mailing List , "acme@kernel.org" , Peter Zijlstra , "mingo@redhat.com" , "linux-mediatek@lists.infradead.org" , "julien.thierry.kdev@gmail.com" , "matthias.bgg@gmail.com" , "namhyung@kernel.org" , Will Deacon , linux-arm-kernel , Linuxarm References: <20200516124857.75004-1-lecopzer@gmail.com> <20200518104524.GA1224@C02TD0UTHF1T.local> <8a1022c0-da2b-c83d-81cd-44b11149496b@arm.com> From: Alexandru Elisei Message-ID: <1d615c32-89f0-d9ba-43db-3d90c7d53e15@arm.com> Date: Thu, 21 May 2020 13:36:06 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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