From patchwork Mon Mar 7 15:47:25 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lecopzer Chen X-Patchwork-Id: 12772053 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 99CC7C433EF for ; Mon, 7 Mar 2022 15:51:09 +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:References:In-Reply-To: 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: List-Owner; bh=9eBQA5551iGmDQ1yYYLBUE7sAoSf2y5gl5dtuDzsqfc=; b=cTxuLIvuXD+55d W8bJncnXo8z7XG5QS8aP6FsN+llDC8Ua4SpGomqLScczBxwQ811N9pGO1R7KeFTfBDsjyybKd4TyO moHzA8TY7Lhi1ZpglkKkjxa5FMSZykax4SyQI+5a/9yZEpw/KVKJ/t9TWMwgxYzPV0CuRw58E91S1 flNd9s1/9p9bSWLX8dxYspjVbB96P914Ca/1+nGGMpdFIYWggX406IvZyQOHo/+X31zSZlxJuuGVL cu9l667vPoWMcRRWAZzNuIbwy8NKXO47n3upOTAIv6hpwENV9KWoPNsii6kxdj0E/XpiYmO+JQz8l iqnnj52gt+NmAtDY3nQg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nRFcR-000hjh-Jg; Mon, 07 Mar 2022 15:49:55 +0000 Received: from mailgw01.mediatek.com ([216.200.240.184]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nRFav-000gxq-IS; Mon, 07 Mar 2022 15:48:23 +0000 X-UUID: 94a8496df9074dc999b0471d982338b4-20220307 X-UUID: 94a8496df9074dc999b0471d982338b4-20220307 Received: from mtkcas67.mediatek.inc [(172.29.193.45)] by mailgw01.mediatek.com (envelope-from ) (musrelay.mediatek.com ESMTP with TLSv1.2 ECDHE-RSA-AES256-SHA384 256/256) with ESMTP id 815334611; Mon, 07 Mar 2022 08:48:16 -0700 Received: from mtkexhb02.mediatek.inc (172.21.101.103) by MTKMBS62N1.mediatek.inc (172.29.193.41) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Mon, 7 Mar 2022 07:48:14 -0800 Received: from mtkcas11.mediatek.inc (172.21.101.40) by mtkexhb02.mediatek.inc (172.21.101.103) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Mon, 7 Mar 2022 23:48:01 +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 23:48:00 +0800 From: Lecopzer Chen To: CC: , , , , , , , , , , , , , , , , , , , , , , , , , , , Subject: [PATCH v2 1/5] kernel/watchdog: remove WATCHDOG_DEFAULT Date: Mon, 7 Mar 2022 23:47:25 +0800 Message-ID: <20220307154729.13477-2-lecopzer.chen@mediatek.com> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20220307154729.13477-1-lecopzer.chen@mediatek.com> References: <20220307154729.13477-1-lecopzer.chen@mediatek.com> MIME-Version: 1.0 X-MTK: N X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220307_074821_637318_DA7CD71D X-CRM114-Status: UNSURE ( 7.81 ) X-CRM114-Notice: Please train this message. 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 No reference to WATCHDOG_DEFAULT, remove it. Signed-off-by: Pingfan Liu Signed-off-by: Lecopzer Chen Reviewed-by: Petr Mladek --- kernel/watchdog.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/kernel/watchdog.c b/kernel/watchdog.c index 99afb88d2e85..db451e943a04 100644 --- a/kernel/watchdog.c +++ b/kernel/watchdog.c @@ -30,10 +30,8 @@ static DEFINE_MUTEX(watchdog_mutex); #if defined(CONFIG_HARDLOCKUP_DETECTOR) || defined(CONFIG_HAVE_NMI_WATCHDOG) -# define WATCHDOG_DEFAULT (SOFT_WATCHDOG_ENABLED | NMI_WATCHDOG_ENABLED) # define NMI_WATCHDOG_DEFAULT 1 #else -# define WATCHDOG_DEFAULT (SOFT_WATCHDOG_ENABLED) # define NMI_WATCHDOG_DEFAULT 0 #endif From patchwork Mon Mar 7 15:47:26 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lecopzer Chen X-Patchwork-Id: 12772052 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 49B1EC433F5 for ; Mon, 7 Mar 2022 15:50:53 +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:References:In-Reply-To: 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: List-Owner; bh=dGZOLgc/QEOuT7prmuITllrQSoW1x2KkI52G4DdmOwU=; b=q5bBqpcuoC8iWv h0WZjbduy2laWCgozoiepQUwHZQsiSeyOjr2gz4L9aSrXD/Swlk9Ds7xS7Hk3d5ZpK4mXvcaazX5g 7EWj+i3BrezIK512ffgT4awKSKf9kITwHee2OBz93FE3+5El/WsPFDuty+Wbw/BUbsPeWGq8neLff 826e2JM2gSoc3FNyzugVD57OLZ50D+E+w1VnXrW9ipdY0luyDJ0aM0mUUi/UrfKiz8MgSNBCffbGK VdFfJfAJZYB01xZtl8u2fMOlbgm1OKQHbBjvSkEAM2aVCLPDQv+ZGjEPqYLRtRD3+k44glqz31WRQ 5ssyxiH/4q3DjmCroGaA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nRFc5-000hXd-7i; Mon, 07 Mar 2022 15:49:33 +0000 Received: from mailgw01.mediatek.com ([216.200.240.184]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nRFau-000gwV-Lr; Mon, 07 Mar 2022 15:48:22 +0000 X-UUID: 78422e7fd00a4d45953ebaa4cf41c563-20220307 X-UUID: 78422e7fd00a4d45953ebaa4cf41c563-20220307 Received: from mtkcas67.mediatek.inc [(172.29.193.45)] by mailgw01.mediatek.com (envelope-from ) (musrelay.mediatek.com ESMTP with TLSv1.2 ECDHE-RSA-AES256-SHA384 256/256) with ESMTP id 1853331508; Mon, 07 Mar 2022 08:48:16 -0700 Received: from mtkexhb02.mediatek.inc (172.21.101.103) by MTKMBS62N1.mediatek.inc (172.29.193.41) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Mon, 7 Mar 2022 07:48:15 -0800 Received: from mtkcas11.mediatek.inc (172.21.101.40) by mtkexhb02.mediatek.inc (172.21.101.103) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Mon, 7 Mar 2022 23:48:02 +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 23:48:01 +0800 From: Lecopzer Chen To: CC: , , , , , , , , , , , , , , , , , , , , , , , , , , , Subject: [PATCH v2 2/5] kernel/watchdog: change watchdog_nmi_enable() to void Date: Mon, 7 Mar 2022 23:47:26 +0800 Message-ID: <20220307154729.13477-3-lecopzer.chen@mediatek.com> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20220307154729.13477-1-lecopzer.chen@mediatek.com> References: <20220307154729.13477-1-lecopzer.chen@mediatek.com> MIME-Version: 1.0 X-MTK: N X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220307_074820_766369_BD516F21 X-CRM114-Status: GOOD ( 11.70 ) 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 Nobody cares about the return value of watchdog_nmi_enable(), changing its prototype to void. Signed-off-by: Pingfan Liu Signed-off-by: Lecopzer Chen Reviewed-by: Petr Mladek --- arch/sparc/kernel/nmi.c | 8 +++----- include/linux/nmi.h | 2 +- kernel/watchdog.c | 3 +-- 3 files changed, 5 insertions(+), 8 deletions(-) diff --git a/arch/sparc/kernel/nmi.c b/arch/sparc/kernel/nmi.c index 060fff95a305..5dcf31f7e81f 100644 --- a/arch/sparc/kernel/nmi.c +++ b/arch/sparc/kernel/nmi.c @@ -282,11 +282,11 @@ __setup("nmi_watchdog=", setup_nmi_watchdog); * sparc specific NMI watchdog enable function. * Enables watchdog if it is not enabled already. */ -int watchdog_nmi_enable(unsigned int cpu) +void watchdog_nmi_enable(unsigned int cpu) { if (atomic_read(&nmi_active) == -1) { pr_warn("NMI watchdog cannot be enabled or disabled\n"); - return -1; + return; } /* @@ -295,11 +295,9 @@ int watchdog_nmi_enable(unsigned int cpu) * process first. */ if (!nmi_init_done) - return 0; + return; smp_call_function_single(cpu, start_nmi_watchdog, NULL, 1); - - return 0; } /* * sparc specific NMI watchdog disable function. diff --git a/include/linux/nmi.h b/include/linux/nmi.h index 750c7f395ca9..b7bcd63c36b4 100644 --- a/include/linux/nmi.h +++ b/include/linux/nmi.h @@ -119,7 +119,7 @@ static inline int hardlockup_detector_perf_init(void) { return 0; } void watchdog_nmi_stop(void); void watchdog_nmi_start(void); int watchdog_nmi_probe(void); -int watchdog_nmi_enable(unsigned int cpu); +void watchdog_nmi_enable(unsigned int cpu); void watchdog_nmi_disable(unsigned int cpu); /** diff --git a/kernel/watchdog.c b/kernel/watchdog.c index db451e943a04..b71d434cf648 100644 --- a/kernel/watchdog.c +++ b/kernel/watchdog.c @@ -93,10 +93,9 @@ __setup("nmi_watchdog=", hardlockup_panic_setup); * softlockup watchdog start and stop. The arch must select the * SOFTLOCKUP_DETECTOR Kconfig. */ -int __weak watchdog_nmi_enable(unsigned int cpu) +void __weak watchdog_nmi_enable(unsigned int cpu) { hardlockup_detector_perf_enable(); - return 0; } void __weak watchdog_nmi_disable(unsigned int cpu) From patchwork Mon Mar 7 15:47:27 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lecopzer Chen X-Patchwork-Id: 12772049 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 E53B5C433EF for ; Mon, 7 Mar 2022 15:49:53 +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:References:In-Reply-To: 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: List-Owner; bh=+YL1rUmWBOahpRjOHl/RI1n8f0sbvs0WDzV+Io9zBc8=; b=S3mQosThWDPFCS svZBQjC63okjDPvjHB2lyIKN0OT4YDLSCG5mOmasV0R6pgnHMa1BSIVFKxWXtQ9Qp1ilJNce0+h2Q OSrq62qrd58HEENQORfXG2sk+i4zXU15Xm0dXmdPnqCAmY7ZQr6Q0Z4pxqwn4mK96R6JHExqboV/V hWjbJgmueRAXvMQ/lkV7vy8E77pc8fXzs7kxaddUf9XijjrJxHK8K6zCc124hsGyke5tpjBdZpfbN +d/oYK5p1f8KDWY/pHEha7vtshmK8wbnRcn5EnP70GUb/1j7PkUl6oYnCt/Vmx7kluSqLexCOu+g+ G//FMUBwHjucRSbe6Afg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nRFb1-000gxg-VW; Mon, 07 Mar 2022 15:48:29 +0000 Received: from mailgw01.mediatek.com ([216.200.240.184]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nRFan-000gpO-5R; Mon, 07 Mar 2022 15:48:14 +0000 X-UUID: 0fb53cdb0db14143ab70c4482de56dd8-20220307 X-UUID: 0fb53cdb0db14143ab70c4482de56dd8-20220307 Received: from mtkcas66.mediatek.inc [(172.29.193.44)] by mailgw01.mediatek.com (envelope-from ) (musrelay.mediatek.com ESMTP with TLSv1.2 ECDHE-RSA-AES256-SHA384 256/256) with ESMTP id 910439454; Mon, 07 Mar 2022 08:48:06 -0700 Received: from mtkmbs10n2.mediatek.inc (172.21.101.183) by MTKMBS62N2.mediatek.inc (172.29.193.42) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Mon, 7 Mar 2022 07:48:04 -0800 Received: from mtkcas11.mediatek.inc (172.21.101.40) by mtkmbs10n2.mediatek.inc (172.21.101.183) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id 15.2.792.3; Mon, 7 Mar 2022 23:48:03 +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 23:48:02 +0800 From: Lecopzer Chen To: CC: , , , , , , , , , , , , , , , , , , , , , , , , , , , Subject: [PATCH v2 3/5] kernel/watchdog_hld: Ensure CPU-bound context when creating hardlockup detector event Date: Mon, 7 Mar 2022 23:47:27 +0800 Message-ID: <20220307154729.13477-4-lecopzer.chen@mediatek.com> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20220307154729.13477-1-lecopzer.chen@mediatek.com> References: <20220307154729.13477-1-lecopzer.chen@mediatek.com> MIME-Version: 1.0 X-MTK: N X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220307_074813_243037_FB0CFECF X-CRM114-Status: GOOD ( 12.67 ) 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 From: Pingfan Liu hardlockup_detector_event_create() should create perf_event on the current CPU. Preemption could not get disabled because perf_event_create_kernel_counter() allocates memory. Instead, the CPU locality is achieved by processing the code in a per-CPU bound kthread. Add a check to prevent mistakes when calling the code in another code path. Signed-off-by: Pingfan Liu Co-developed-by: Lecopzer Chen Signed-off-by: Lecopzer Chen Reviewed-by: Petr Mladek --- kernel/watchdog_hld.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/kernel/watchdog_hld.c b/kernel/watchdog_hld.c index 247bf0b1582c..96b717205952 100644 --- a/kernel/watchdog_hld.c +++ b/kernel/watchdog_hld.c @@ -165,10 +165,16 @@ static void watchdog_overflow_callback(struct perf_event *event, static int hardlockup_detector_event_create(void) { - unsigned int cpu = smp_processor_id(); + unsigned int cpu; struct perf_event_attr *wd_attr; struct perf_event *evt; + /* + * Preemption is not disabled because memory will be allocated. + * Ensure CPU-locality by calling this in per-CPU kthread. + */ + WARN_ON(!is_percpu_thread()); + cpu = raw_smp_processor_id(); wd_attr = &wd_hw_attr; wd_attr->sample_period = hw_nmi_get_sample_period(watchdog_thresh); From patchwork Mon Mar 7 15:47:28 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lecopzer Chen X-Patchwork-Id: 12772050 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 1F15CC433EF for ; Mon, 7 Mar 2022 15:50:19 +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:References:In-Reply-To: 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: List-Owner; bh=ccNZrWTDEZahEu2ysRHuMxVuI2z9NVxZpqu2TNywNQI=; b=D3Ra3Xh+sfcKgc j81Xq+jRbT3OLrx+DWLFoN3zmp6Q4ti5IaRXB6PwG8lWufpSlMRJXOMHmBXVfVzUjyUEwSlD1hsOh ofeN02VSlX+epw9ZaC7+ams7FRIcr++BTtGB+B/a5E78RvxbYL3f3i4iwj25aP7E18V9+Y+IHFOrV c3wzCKQIbF7RH1R4CZshjSuwXbhzhCSlvizJ5tpc/7+YGMyoPeDE6/wCUmy/xBZHVpAd9wrdJMtyE lsOu3Lz0vDCmGUjESUY9sjJnhPAEGqfz3OKVj3WYEqafMaJ4xpQupjgJZv8GQDCwMLFggLO2ie5/2 yLctUB9rznjFTJwuICUw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nRFbU-000hIC-Gd; Mon, 07 Mar 2022 15:48:56 +0000 Received: from mailgw01.mediatek.com ([216.200.240.184]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nRFan-000gpW-Gz; Mon, 07 Mar 2022 15:48:15 +0000 X-UUID: e438ad9a9c95498da893a556f7056f9b-20220307 X-UUID: e438ad9a9c95498da893a556f7056f9b-20220307 Received: from mtkcas66.mediatek.inc [(172.29.193.44)] by mailgw01.mediatek.com (envelope-from ) (musrelay.mediatek.com ESMTP with TLSv1.2 ECDHE-RSA-AES256-SHA384 256/256) with ESMTP id 642656085; Mon, 07 Mar 2022 08:48:06 -0700 Received: from MTKMBS07N2.mediatek.inc (172.21.101.141) by MTKMBS62N2.mediatek.inc (172.29.193.42) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Mon, 7 Mar 2022 07:48:05 -0800 Received: from mtkcas11.mediatek.inc (172.21.101.40) by mtkmbs07n2.mediatek.inc (172.21.101.141) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Mon, 7 Mar 2022 23:48:03 +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 23:48:03 +0800 From: Lecopzer Chen To: CC: , , , , , , , , , , , , , , , , , , , , , , , , , , , Subject: [PATCH v2 4/5] kernel/watchdog: Adapt the watchdog_hld interface for async model Date: Mon, 7 Mar 2022 23:47:28 +0800 Message-ID: <20220307154729.13477-5-lecopzer.chen@mediatek.com> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20220307154729.13477-1-lecopzer.chen@mediatek.com> References: <20220307154729.13477-1-lecopzer.chen@mediatek.com> MIME-Version: 1.0 X-MTK: N X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220307_074813_630441_31678712 X-CRM114-Status: GOOD ( 19.18 ) 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 When lockup_detector_init()->watchdog_nmi_probe(), PMU may be not ready yet. E.g. on arm64, 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 this initialization 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. Co-developed-by: Pingfan Liu Signed-off-by: Pingfan Liu Signed-off-by: Lecopzer Chen Suggested-by: Petr Mladek --- include/linux/nmi.h | 3 +++ kernel/watchdog.c | 62 +++++++++++++++++++++++++++++++++++++++++++-- 2 files changed, 63 insertions(+), 2 deletions(-) diff --git a/include/linux/nmi.h b/include/linux/nmi.h index b7bcd63c36b4..cc7df31be9db 100644 --- a/include/linux/nmi.h +++ b/include/linux/nmi.h @@ -118,6 +118,9 @@ static inline int hardlockup_detector_perf_init(void) { return 0; } void watchdog_nmi_stop(void); void watchdog_nmi_start(void); + +extern bool lockup_detector_pending_init; +extern struct wait_queue_head hld_detector_wait; int watchdog_nmi_probe(void); void watchdog_nmi_enable(unsigned int cpu); void watchdog_nmi_disable(unsigned int cpu); diff --git a/kernel/watchdog.c b/kernel/watchdog.c index b71d434cf648..49bdcaf5bd8f 100644 --- a/kernel/watchdog.c +++ b/kernel/watchdog.c @@ -103,7 +103,11 @@ void __weak watchdog_nmi_disable(unsigned int cpu) hardlockup_detector_perf_disable(); } -/* Return 0, if a NMI watchdog is available. Error code otherwise */ +/* + * Arch specific API. Return 0, if a NMI watchdog is available. -EBUSY if not + * ready, and arch code should wake up hld_detector_wait when ready. Other + * negative value if not support. + */ int __weak __init watchdog_nmi_probe(void) { return hardlockup_detector_perf_init(); @@ -839,16 +843,70 @@ static void __init watchdog_sysctl_init(void) #define watchdog_sysctl_init() do { } while (0) #endif /* CONFIG_SYSCTL */ +static void lockup_detector_delay_init(struct work_struct *work); +bool lockup_detector_pending_init __initdata; + +struct wait_queue_head hld_detector_wait __initdata = + __WAIT_QUEUE_HEAD_INITIALIZER(hld_detector_wait); + +static struct work_struct detector_work __initdata = + __WORK_INITIALIZER(detector_work, lockup_detector_delay_init); + +static void __init lockup_detector_delay_init(struct work_struct *work) +{ + int ret; + + wait_event(hld_detector_wait, + lockup_detector_pending_init == false); + + /* + * Here, we know the PMU should be ready, so set pending to true to + * inform watchdog_nmi_probe() that it shouldn't return -EBUSY again. + */ + lockup_detector_pending_init = true; + ret = watchdog_nmi_probe(); + if (ret) { + pr_info("Delayed init of the lockup detector failed: %d\n", ret); + pr_info("Perf NMI watchdog permanently disabled\n"); + return; + } + + nmi_watchdog_available = true; + lockup_detector_setup(); + lockup_detector_pending_init = false; +} + +/* Ensure the check is called after the initialization of PMU driver */ +static int __init lockup_detector_check(void) +{ + if (!lockup_detector_pending_init) + return 0; + + pr_info("Delayed init checking failed, retry for once.\n"); + lockup_detector_pending_init = false; + wake_up(&hld_detector_wait); + return 0; +} +late_initcall_sync(lockup_detector_check); + void __init lockup_detector_init(void) { + int ret; + if (tick_nohz_full_enabled()) pr_info("Disabling watchdog on nohz_full cores by default\n"); cpumask_copy(&watchdog_cpumask, housekeeping_cpumask(HK_FLAG_TIMER)); - if (!watchdog_nmi_probe()) + ret = watchdog_nmi_probe(); + if (!ret) nmi_watchdog_available = true; + else if (ret == -EBUSY) { + lockup_detector_pending_init = true; + queue_work_on(smp_processor_id(), system_wq, &detector_work); + } + lockup_detector_setup(); watchdog_sysctl_init(); } From patchwork Mon Mar 7 15:47:29 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lecopzer Chen X-Patchwork-Id: 12772051 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 84514C433F5 for ; Mon, 7 Mar 2022 15:50:24 +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:References:In-Reply-To: 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: List-Owner; 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Mon, 07 Mar 2022 08:48:07 -0700 Received: from MTKMBS07N2.mediatek.inc (172.21.101.141) by MTKMBS62N2.mediatek.inc (172.29.193.42) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Mon, 7 Mar 2022 07:48:06 -0800 Received: from mtkcas11.mediatek.inc (172.21.101.40) by mtkmbs07n2.mediatek.inc (172.21.101.141) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Mon, 7 Mar 2022 23:48:04 +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 23:48:04 +0800 From: Lecopzer Chen To: CC: , , , , , , , , , , , , , , , , , , , , , , , , , , , Subject: [PATCH v2 5/5] arm64: Enable perf events based hard lockup detector Date: Mon, 7 Mar 2022 23:47:29 +0800 Message-ID: <20220307154729.13477-6-lecopzer.chen@mediatek.com> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20220307154729.13477-1-lecopzer.chen@mediatek.com> References: <20220307154729.13477-1-lecopzer.chen@mediatek.com> MIME-Version: 1.0 X-MTK: N X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220307_074816_038385_0AD47A5B X-CRM114-Status: GOOD ( 18.92 ) 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 With the recent feature added to enable perf events to use pseudo NMIs as interrupts on platforms which support GICv3 or later, its now been possible to enable hard lockup detector (or NMI watchdog) on arm64 platforms. So enable corresponding support. One thing to note here is that normally lockup detector is initialized just after the early initcalls but PMU on arm64 comes up much later as device_initcall(). To cope with that, overriding watchdog_nmi_probe() to let the watchdog framework know PMU not ready, and inform the framework to re-initialize lockup detection once PMU has been initialized. [1]: http://lore.kernel.org/linux-arm-kernel/1610712101-14929-1-git-send-email-sumit.garg@linaro.org Co-developed-by: Sumit Garg Signed-off-by: Sumit Garg Co-developed-by: Pingfan Liu Signed-off-by: Pingfan Liu Signed-off-by: Lecopzer Chen --- arch/arm64/Kconfig | 2 ++ arch/arm64/kernel/Makefile | 1 + arch/arm64/kernel/perf_event.c | 12 ++++++++++-- drivers/perf/arm_pmu.c | 5 +++++ include/linux/perf/arm_pmu.h | 2 ++ 5 files changed, 20 insertions(+), 2 deletions(-) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 09b885cc4db5..df6fed8327ba 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -190,6 +190,8 @@ config ARM64 select HAVE_NMI select HAVE_PATA_PLATFORM select HAVE_PERF_EVENTS + select HAVE_PERF_EVENTS_NMI if ARM64_PSEUDO_NMI + select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI select HAVE_PERF_REGS select HAVE_PERF_USER_STACK_DUMP select HAVE_REGS_AND_STACK_ACCESS_API diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile index 88b3e2a21408..3e62a8877ed7 100644 --- a/arch/arm64/kernel/Makefile +++ b/arch/arm64/kernel/Makefile @@ -46,6 +46,7 @@ obj-$(CONFIG_MODULES) += module.o obj-$(CONFIG_ARM64_MODULE_PLTS) += module-plts.o obj-$(CONFIG_PERF_EVENTS) += perf_regs.o perf_callchain.o obj-$(CONFIG_HW_PERF_EVENTS) += perf_event.o +obj-$(CONFIG_HARDLOCKUP_DETECTOR_PERF) += watchdog_hld.o obj-$(CONFIG_HAVE_HW_BREAKPOINT) += hw_breakpoint.o obj-$(CONFIG_CPU_PM) += sleep.o suspend.o obj-$(CONFIG_CPU_IDLE) += cpuidle.o diff --git a/arch/arm64/kernel/perf_event.c b/arch/arm64/kernel/perf_event.c index cab678ed6618..77eaefee13ea 100644 --- a/arch/arm64/kernel/perf_event.c +++ b/arch/arm64/kernel/perf_event.c @@ -23,6 +23,7 @@ #include #include #include +#include /* ARMv8 Cortex-A53 specific event types. */ #define ARMV8_A53_PERFCTR_PREF_LINEFILL 0xC2 @@ -1380,10 +1381,17 @@ static struct platform_driver armv8_pmu_driver = { static int __init armv8_pmu_driver_init(void) { + int ret; + if (acpi_disabled) - return platform_driver_register(&armv8_pmu_driver); + ret = platform_driver_register(&armv8_pmu_driver); else - return arm_pmu_acpi_probe(armv8_pmuv3_pmu_init); + ret = arm_pmu_acpi_probe(armv8_pmuv3_pmu_init); + + /* Inform watchdog core we are ready to probe hld by delayed init. */ + lockup_detector_pending_init = false; + wake_up(&hld_detector_wait); + return ret; } device_initcall(armv8_pmu_driver_init) diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c index 295cc7952d0e..e77f4897fca2 100644 --- a/drivers/perf/arm_pmu.c +++ b/drivers/perf/arm_pmu.c @@ -697,6 +697,11 @@ static int armpmu_get_cpu_irq(struct arm_pmu *pmu, int cpu) return per_cpu(hw_events->irq, cpu); } +bool arm_pmu_irq_is_nmi(void) +{ + return has_nmi; +} + /* * PMU hardware loses all context when a CPU goes offline. * When a CPU is hotplugged back in, since some hardware registers are diff --git a/include/linux/perf/arm_pmu.h b/include/linux/perf/arm_pmu.h index 2512e2f9cd4e..9325d01adc3e 100644 --- a/include/linux/perf/arm_pmu.h +++ b/include/linux/perf/arm_pmu.h @@ -169,6 +169,8 @@ void kvm_host_pmu_init(struct arm_pmu *pmu); #define kvm_host_pmu_init(x) do { } while(0) #endif +bool arm_pmu_irq_is_nmi(void); + /* Internal functions only for core arm_pmu code */ struct arm_pmu *armpmu_alloc(void); struct arm_pmu *armpmu_alloc_atomic(void);