From patchwork Mon Mar 7 15:47:24 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lecopzer Chen X-Patchwork-Id: 12772068 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id CC663C433EF for ; Mon, 7 Mar 2022 15:59:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-ID:Date:Subject:CC :To:From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=wOVowmkw9D3gHZijoUe20wDYsl5gb2/VhN3tVag69EU=; b=uLvZJaRlfKOAdX Flru4w4xyevdcX8FImdrgP6EJtu9G/fWz0wNZtnFfc4587d8pMxQ8eJ48fAGRZFzqDVyb9RA4E2kc 5SYJjXcpTEKEyrmM0cmIyZkuH/4bHYoSFOefuw4A6pbrdX8khchUikox6GeZZMemw1g9Zfl00Qzx/ q3fASQj4g3I/veCFd36FJHs6e8JIJ4W9xOnTgCZU2HJI8aGDS2xFMAJTr89+BMx9PYanZaC5ORUf6 TkXoNFQnDTu4oH2dVLwdPdi8p0lcRbUxJQZa6YJKocxpz4HkyHwKpow3edMTTEToRafS78Qv9ueNl uEeFdbXj3QJv+vHCYezQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nRFkc-000lLH-FU; Mon, 07 Mar 2022 15:58:23 +0000 Received: from mailgw02.mediatek.com ([216.200.240.185]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nRFkV-000lGJ-Um; Mon, 07 Mar 2022 15:58:18 +0000 X-UUID: f28da88335694567809102b0dc9afa75-20220307 X-UUID: f28da88335694567809102b0dc9afa75-20220307 Received: from mtkcas66.mediatek.inc [(172.29.193.44)] by mailgw02.mediatek.com (envelope-from ) (musrelay.mediatek.com ESMTP with TLSv1.2 ECDHE-RSA-AES256-SHA384 256/256) with ESMTP id 1867811872; Mon, 07 Mar 2022 08:58:11 -0700 Received: from mtkexhb01.mediatek.inc (172.21.101.102) by MTKMBS62DR.mediatek.inc (172.29.94.18) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Mon, 7 Mar 2022 07:48:09 -0800 Received: from mtkcas11.mediatek.inc (172.21.101.40) by mtkexhb01.mediatek.inc (172.21.101.102) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Mon, 7 Mar 2022 23:47:55 +0800 Received: from mtksdccf07.mediatek.inc (172.21.84.99) by mtkcas11.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Mon, 7 Mar 2022 23:47:54 +0800 From: Lecopzer Chen To: CC: , , , , , , , , , , , , , , , , , , , , , , , , , , , Subject: [PATCH v2 0/5] Suppot hld based on Pseudo-NMI for arm64 Date: Mon, 7 Mar 2022 23:47:24 +0800 Message-ID: <20220307154729.13477-1-lecopzer.chen@mediatek.com> X-Mailer: git-send-email 2.18.0 MIME-Version: 1.0 X-MTK: N X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220307_075816_030743_FDEB256A X-CRM114-Status: GOOD ( 15.02 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org As we already used hld internally for arm64 since 2020, there still doesn't have a proper commit on the upstream and we badly need it. This serise rework on 5.17-rc7 from [1] and the origin author is Pingfan Liu Sumit Garg Qoute from [1]: > Hard lockup detector is helpful to diagnose unpaired irq enable/disable. > But the current watchdog framework can not cope with arm64 hw perf event > easily. > On arm64, when lockup_detector_init()->watchdog_nmi_probe(), PMU is not > ready until device_initcall(armv8_pmu_driver_init). And it is deeply > integrated with the driver model and cpuhp. Hence it is hard to push the > initialization of armv8_pmu_driver_init() before smp_init(). > But it is easy to take an opposite approach by enabling watchdog_hld to > get the capability of PMU async. > The async model is achieved by expanding watchdog_nmi_probe() with > -EBUSY, and a re-initializing work_struct which waits on a > wait_queue_head. [1] https://lore.kernel.org/lkml/20211014024155.15253-1-kernelfans@gmail.com/ v2: 1. Tweak commit message in patch 01/02/04/05 2. Remove vobose WARN in patch 04 within watchdog core. 3. Change from three states variable: detector_delay_init_state to two states variable: lockup_detector_pending_init Thanks Petr Mladek for the idea. > 1. lockup_detector_work() called before lockup_detector_check(). > In this case, wait_event() will wait until lockup_detector_check() > clears detector_delay_pending_init and calls wake_up(). > 2. lockup_detector_check() called before lockup_detector_work(). > In this case, wait_even() will immediately continue because > it will see cleared detector_delay_pending_init. 4. Add comment in code in patch 04/05 for two states variable changing. Lecopzer Chen (4): kernel/watchdog: remove WATCHDOG_DEFAULT kernel/watchdog: change watchdog_nmi_enable() to void kernel/watchdog: Adapt the watchdog_hld interface for async model arm64: Enable perf events based hard lockup detector Pingfan Liu (1): kernel/watchdog_hld: Ensure CPU-bound context when creating hardlockup detector event arch/arm64/Kconfig | 2 + arch/arm64/kernel/Makefile | 1 + arch/arm64/kernel/perf_event.c | 12 +++++- arch/sparc/kernel/nmi.c | 8 ++-- drivers/perf/arm_pmu.c | 5 +++ include/linux/nmi.h | 5 ++- include/linux/perf/arm_pmu.h | 2 + kernel/watchdog.c | 67 +++++++++++++++++++++++++++++++--- kernel/watchdog_hld.c | 8 +++- 9 files changed, 95 insertions(+), 15 deletions(-)