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 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 8F316C28CF5 for ; Wed, 26 Jan 2022 08:58:40 +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:Cc:To:From:Subject:Mime-Version: Message-Id:Date: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=Yi+oheg4khiz4a7qFsyN3bm01X3tYKbUvky7WxwDi9w=; b=MHD CfCwU7KvnPqHoT9mQEOj8q35oygOCrRevGdiyczV+UOEZaa3KFCBEXBGB9TqduSjpgdrLtbWFyrkW a6rZ/eL9Q0D9Yqv/2MyK8YTj4ofzDvgJELz3vPeI98bKBJQq2ObS7h7dRsrIiG1KNqmDz1gpzYNpF b7ko3kdIJLonqEiJTSiZfIMDDzzFco/o5PDrJVjDV6jFagYpQoU3FXIrmFw/9XLKnXuODLoodwsfs tY9wizENLMe73ataINySFBLQiCmGoBlGIJArwVdC8JglBDNrqwVm8gGvJZ0nMXkrppphIVqIOj8R0 3dReT0gGi2R80Ma2AlZrQB+8BPDv3RQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nCe7c-00AotU-Ar; Wed, 26 Jan 2022 08:57:44 +0000 Received: from mail-yb1-xb49.google.com ([2607:f8b0:4864:20::b49]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nCe7Z-00AosD-G8 for linux-mtd@lists.infradead.org; Wed, 26 Jan 2022 08:57:42 +0000 Received: by mail-yb1-xb49.google.com with SMTP id c7-20020a25a2c7000000b00613e4dbaf97so42914122ybn.13 for ; Wed, 26 Jan 2022 00:57:40 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:message-id:mime-version:subject:from:to:cc; bh=lwgxdYwkYYoV60lC8eOCPlgo4Kltdl+GrrvrUKoXqeE=; b=GCHZoL2KMYN56Bb9bArQotAcUIaGcFRa4jJ0xMUOzCWB9X1/MdLNz/kq9Eud0X6jQR OItIooe8ERGMPdHPWn3T2DvWBEBvVwttzLV9fJbfUp++vVxM2nsV9AQTeGPXR2vk/KP0 VpBiTkPR9Vplkpa4chZkwDEk6Lpe53fthwT9JbX2Kbi7rZyl4BLiF5B08Ww2wv8Z2X3y XDx69Pt0QAjeonxrtPJu6R7M1Ca3PoSpoSK4+zQ4UPo4dIhDkdua0AkRIbIKQRq2NNAK Wb3griZiPsq3QsJ1CFiYegt1R43GczSoObqOUZ3xh8PDwR95RF6uMioikK2bJ213wfFG VVlA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=lwgxdYwkYYoV60lC8eOCPlgo4Kltdl+GrrvrUKoXqeE=; b=a+ClJxFDsk/Kc4r8ck57NAvFbC0mOeN5DPsIfmHWT9Mu8EOsN5tg+dLBns9LPAUdUR 2R1Zt/KA5ab7bsOuYiwu9kQP21UuuJjR0IHdULwj+Rl81r+RFSe4PvP1YpJGILbH7Od+ FTKj51zCZz8rJeCV+s+0Go16InmQHvS61tHLyUk+7cqvM5mIpjXjABtNw1UUgmMJKiQf pkvnC3LeJETMoWlJZH5urv1o6PbIc6SpdT0mTZs/3V6ZNO9lp4x4KdFpGZI34SWGsAed W4E4k6N2pbwzWwWDbZuS59wl2YtXBvAcxW6JX7H+HclmomajiB0gpRu957KUBK0vDD3D YprA== X-Gm-Message-State: AOAM533v6dzShiHza65KHkI41robzOBQB2TjUdzd8ygxMQJEI3abw6yg PI2btugiswjSoqdatARzxW9xpylD/w== X-Google-Smtp-Source: ABdhPJxcNL7P3y0SVGcvCOiZCO4BPDNhBNML9s720/dkl9zginGY5V7+nVvKQmx6XPU7EOLpV8e748k2fQ== X-Received: from decot.svl.corp.google.com ([2620:15c:2c5:11:bb79:635d:80b2:3c02]) (user=decot job=sendgmr) by 2002:a81:a89:0:b0:2ca:287c:6d32 with SMTP id 00721157ae682-2ca287c6f7bmr6600087b3.471.1643187459021; Wed, 26 Jan 2022 00:57:39 -0800 (PST) Date: Wed, 26 Jan 2022 00:57:35 -0800 Message-Id: <20220126085735.575625-1-decot+git@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.35.0.rc0.227.g00780c9af4-goog Subject: [PATCH RFC v1 1/1] mtd_blkdevs: avoid soft lockups with some mtd/spi devices From: David Decotigny To: linux-kernel@vger.kernel.org Cc: Miquel Raynal , Richard Weinberger , Vignesh Raghavendra , linux-mtd@lists.infradead.org, David Decotigny X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220126_005741_572940_680F0D95 X-CRM114-Status: GOOD ( 10.96 ) X-BeenThere: linux-mtd@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-mtd" Errors-To: linux-mtd-bounces+linux-mtd=archiver.kernel.org@lists.infradead.org From: David Decotigny With some spi devices, the heavy cpu usage due to polling the spi registers may lead to netdev timeouts, RCU complaints, etc. This can be acute in the absence of CONFIG_PREEMPT. This patch allows to give enough breathing room to avoid those false positives. Signed-off-by: David Decotigny --- I tested this on a 5.10 base (lockdep). drivers/mtd/mtd_blkdevs.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/mtd/mtd_blkdevs.c b/drivers/mtd/mtd_blkdevs.c index 243f28a3206b4..64d2b093f114b 100644 --- a/drivers/mtd/mtd_blkdevs.c +++ b/drivers/mtd/mtd_blkdevs.c @@ -158,6 +158,7 @@ static void mtd_blktrans_work(struct mtd_blktrans_dev *dev) } background_done = 0; + cond_resched(); spin_lock_irq(&dev->queue_lock); } } -- 2.35.0.rc0.227.g00780c9af4-goog ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/ 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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C7A6FC2BA4C for ; Wed, 26 Jan 2022 08:57:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238634AbiAZI5m (ORCPT ); Wed, 26 Jan 2022 03:57:42 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36462 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230348AbiAZI5k (ORCPT ); Wed, 26 Jan 2022 03:57:40 -0500 Received: from mail-yb1-xb49.google.com (mail-yb1-xb49.google.com [IPv6:2607:f8b0:4864:20::b49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 84556C06161C for ; Wed, 26 Jan 2022 00:57:40 -0800 (PST) Received: by mail-yb1-xb49.google.com with SMTP id s7-20020a5b0447000000b005fb83901511so46763444ybp.11 for ; Wed, 26 Jan 2022 00:57:40 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:message-id:mime-version:subject:from:to:cc; bh=lwgxdYwkYYoV60lC8eOCPlgo4Kltdl+GrrvrUKoXqeE=; b=GCHZoL2KMYN56Bb9bArQotAcUIaGcFRa4jJ0xMUOzCWB9X1/MdLNz/kq9Eud0X6jQR OItIooe8ERGMPdHPWn3T2DvWBEBvVwttzLV9fJbfUp++vVxM2nsV9AQTeGPXR2vk/KP0 VpBiTkPR9Vplkpa4chZkwDEk6Lpe53fthwT9JbX2Kbi7rZyl4BLiF5B08Ww2wv8Z2X3y XDx69Pt0QAjeonxrtPJu6R7M1Ca3PoSpoSK4+zQ4UPo4dIhDkdua0AkRIbIKQRq2NNAK Wb3griZiPsq3QsJ1CFiYegt1R43GczSoObqOUZ3xh8PDwR95RF6uMioikK2bJ213wfFG VVlA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=lwgxdYwkYYoV60lC8eOCPlgo4Kltdl+GrrvrUKoXqeE=; b=adBUIEeX5/LJVv7KRqxF9Pm0FmS6qu9Tv3X5EBMCsbwc6ua8yQGDcQoePxCL1CrPiZ bhEaJA/VKvVey4vCcLO/p26GZmOM07UQM/upvO4EBE6AeYOgmDbPg5pCjRLLdEPFuD+T FN/JEp+8RUZsbru8iGFvt0Z09s1H8mni1cYgNhgDpjRWw/bWmi6ECJqN23B3bph7+2Mm j773OqppTB7VOFrJma2oM2788nRyJ63ROUvjjjYqdg/CUMY7W5dB9TWm64kJ6IdXGLlp 9EZyA1iujuclOFfOOORVVBBwZcU1QEOQj7r80C1OWI//DNocx9rU4l/urjMjLRNzZyjj N5JA== X-Gm-Message-State: AOAM531SsRjPxaIRF4Na22m5grJ+K0QZWlpRerXxFANVAxbEjbMup9ko laAXsNmA7LZrHgQJm9A76kSMXhPHP/e++k6flHTLO4LAmwFXOudRFQIWn+u8pwd7gJMIh8VpUqV QLvoOr2xfE40zvtwgCqjHikB1Enguq2rNWnt/OH7YpmSdlh7QxAjMDkrHg04X7yHw5+M= X-Google-Smtp-Source: ABdhPJxcNL7P3y0SVGcvCOiZCO4BPDNhBNML9s720/dkl9zginGY5V7+nVvKQmx6XPU7EOLpV8e748k2fQ== X-Received: from decot.svl.corp.google.com ([2620:15c:2c5:11:bb79:635d:80b2:3c02]) (user=decot job=sendgmr) by 2002:a81:a89:0:b0:2ca:287c:6d32 with SMTP id 00721157ae682-2ca287c6f7bmr6600087b3.471.1643187459021; Wed, 26 Jan 2022 00:57:39 -0800 (PST) Date: Wed, 26 Jan 2022 00:57:35 -0800 Message-Id: <20220126085735.575625-1-decot+git@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.35.0.rc0.227.g00780c9af4-goog Subject: [PATCH RFC v1 1/1] mtd_blkdevs: avoid soft lockups with some mtd/spi devices From: David Decotigny To: linux-kernel@vger.kernel.org Cc: Miquel Raynal , Richard Weinberger , Vignesh Raghavendra , linux-mtd@lists.infradead.org, David Decotigny Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: David Decotigny With some spi devices, the heavy cpu usage due to polling the spi registers may lead to netdev timeouts, RCU complaints, etc. This can be acute in the absence of CONFIG_PREEMPT. This patch allows to give enough breathing room to avoid those false positives. Signed-off-by: David Decotigny --- I tested this on a 5.10 base (lockdep). drivers/mtd/mtd_blkdevs.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/mtd/mtd_blkdevs.c b/drivers/mtd/mtd_blkdevs.c index 243f28a3206b4..64d2b093f114b 100644 --- a/drivers/mtd/mtd_blkdevs.c +++ b/drivers/mtd/mtd_blkdevs.c @@ -158,6 +158,7 @@ static void mtd_blktrans_work(struct mtd_blktrans_dev *dev) } background_done = 0; + cond_resched(); spin_lock_irq(&dev->queue_lock); } } -- 2.35.0.rc0.227.g00780c9af4-goog