Received: by 2002:ab2:6a05:0:b0:1f8:1780:a4ed with SMTP id w5csp3297680lqo; Wed, 15 May 2024 05:56:04 -0700 (PDT) X-Forwarded-Encrypted: i=3; AJvYcCWbxFqkxvecd0L3Nc+f9jYw4/6lBQJnlsgEZpgO48v78Pdp3ndU6Lgr5tGMzdVSsRRV0669zFcwqPZBuqosE97dFW4Y+xrEuwKvbVoxMQ== X-Google-Smtp-Source: AGHT+IFFna8UiWefHUNR/kfQlEABeHSnQUnLVMpVCQ/5WRdJZ/BDNxs7awjCC+o9KHNstJp03atS X-Received: by 2002:a05:6358:2621:b0:186:27ce:63aa with SMTP id e5c5f4694b2df-193bcfe3cebmr1772597955d.24.1715777763715; Wed, 15 May 2024 05:56:03 -0700 (PDT) ARC-Seal: i=2; a=rsa-sha256; t=1715777763; cv=pass; d=google.com; s=arc-20160816; b=x/TaeEYVE4gS1xqXyGvAhmizHb5UvwxA/qiVWguw/8RXFsJbPQROs060T8GrG8rAVA JW//nwPDOz8/JiQHgJB7AhHwPFJcJEQ0BjnVC7CRvd3HiYQBIqjgoTZ69FE1nFowGfIS cniiav/qISaW0004iivlU2yCMvJZk0WnIPVAEtDCPAPjlZNtsnJXhucIiMwrTYUjyMmB OXWdGYU4mPh5rRCCgXAPQTvi1RmNzMyRUnGeMqBdWX/6HWyH/ZfTINBEDHLSkruiS+Mh 0wfjMyrBGKAv9pLB+pVZ7z0ykxecOwyAXmRw6Mjbz7JRy3h8z9Q8/81iiFUQckldJtCk NNKw== ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=content-transfer-encoding:mime-version:list-unsubscribe :list-subscribe:list-id:precedence:references:in-reply-to:message-id :date:subject:cc:to:from:dkim-signature; bh=lwFCNObJX0XFJa8hB9AVQPbhaHJVkhAUATWysKIQAgU=; fh=GaSAYfh5FLoTC6t2Xhg6bNmq0NjRUvBIE2VOTI0dJc4=; b=Dx6jJY97clhu4DBWNL/GJdX/ManPWfQ5QjV8pwrLolNVmRcyi4ZDHz1PqMSBwTVi4F QQfyWePaZT55yilNrIltoMeR2XWOK8Gt+rFkb8BiZS9Z3jouvg1iEoxVjLzg+ZriDQxQ RNmMJC8I7tGkZ4xfxZmLj8fFs0Qm578d4ZwjA4VJ+MrzZ0MONuIFjojSMBLkDQG7Sskp 3RK9uT86RLxGsKjLYH8BDm49+Gfo7I42ZZpg/tUpTPvfug+gkscpmMtdOswyxHS72ePg ZcICwTkKqI1Hy3sGcji+Zta9F3uaw8ukZSW16sVq1Fxz5hbzIDxBBHW4GRUhHVG1TLTE PQMQ==; dara=google.com ARC-Authentication-Results: i=2; mx.google.com; dkim=pass header.i=@oracle.com header.s=corp-2023-11-20 header.b=jwZU8C3x; arc=pass (i=1 spf=pass spfdomain=oracle.com dkim=pass dkdomain=oracle.com dmarc=pass fromdomain=oracle.com); spf=pass (google.com: domain of linux-kernel+bounces-179863-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:45e3:2400::1 as permitted sender) smtp.mailfrom="linux-kernel+bounces-179863-linux.lists.archive=gmail.com@vger.kernel.org"; dmarc=pass (p=QUARANTINE sp=QUARANTINE dis=NONE) header.from=oracle.com Return-Path: Received: from sv.mirrors.kernel.org (sv.mirrors.kernel.org. [2604:1380:45e3:2400::1]) by mx.google.com with ESMTPS id 41be03b00d2f7-654a527942csi1287335a12.588.2024.05.15.05.56.03 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 15 May 2024 05:56:03 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel+bounces-179863-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:45e3:2400::1 as permitted sender) client-ip=2604:1380:45e3:2400::1; Authentication-Results: mx.google.com; dkim=pass header.i=@oracle.com header.s=corp-2023-11-20 header.b=jwZU8C3x; arc=pass (i=1 spf=pass spfdomain=oracle.com dkim=pass dkdomain=oracle.com dmarc=pass fromdomain=oracle.com); spf=pass (google.com: domain of linux-kernel+bounces-179863-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:45e3:2400::1 as permitted sender) smtp.mailfrom="linux-kernel+bounces-179863-linux.lists.archive=gmail.com@vger.kernel.org"; dmarc=pass (p=QUARANTINE sp=QUARANTINE dis=NONE) header.from=oracle.com Received: from smtp.subspace.kernel.org (wormhole.subspace.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sv.mirrors.kernel.org (Postfix) with ESMTPS id 4452F28530D for ; Wed, 15 May 2024 12:55:44 +0000 (UTC) Received: from localhost.localdomain (localhost.localdomain [127.0.0.1]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 8FA2512C801; Wed, 15 May 2024 12:54:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="jwZU8C3x" Received: from mx0b-00069f02.pphosted.com (mx0b-00069f02.pphosted.com [205.220.177.32]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DBCE6128382; Wed, 15 May 2024 12:54:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=205.220.177.32 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715777666; cv=none; b=dfX4V+rBl93i6NvpzTzY2DK8Or8wI7Kj1Zz/VQ5H+D+/y98tNVnA9FM3VQsbr9gi+r/0HFFYw6Da2RIPUm3pjrzEzLvFR9mnml7/bPanhTT7mBtFSmoljITPaDdj9IU+/+N1v3lcGryf7sd/dppZcPcGMKFhfrkUgdmUK/LOJ28= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715777666; c=relaxed/simple; bh=bC51ekxs+x55vMw5lPjDrzXR33HcuoruRI1JEsJzfAQ=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version:Content-Type; b=nsoFQqTm0CIwfy5yuhbYfiLswqL/vCf7Uw6ua+5JMe1n5uuQD63n5KcdxLT5p45BcSWj/txuCfYzkBgZHRMBb5TPuYPe49nd+TIyXQwF6Y2VpXge5GfJx2sbgAz3pXPN7nkAsrjpm62d4TCrpVfmEhzusH1M2bxLmzhD+KXMMsA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=oracle.com; spf=pass smtp.mailfrom=oracle.com; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b=jwZU8C3x; arc=none smtp.client-ip=205.220.177.32 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=oracle.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=oracle.com Received: from pps.filterd (m0333520.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 44F7n2n4008508; Wed, 15 May 2024 12:54:04 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-type : content-transfer-encoding; s=corp-2023-11-20; bh=lwFCNObJX0XFJa8hB9AVQPbhaHJVkhAUATWysKIQAgU=; b=jwZU8C3x/otvDKVXjLu5jM6iBLWrzNPMqLm5OumM7uLmuVPYNzI/YWNJkaI3BVcJ6d93 9049Uz8Mc8W7z6BARMbO/iM/Q1vtmwzbCb9KisAQcr9gK/WmSktePESkZKMCpm9CbOsB dQBJznWtdS/sys7Q3VqnqLF0ZfT0gzzX5ujb4N2x/InM3YAZ2fh/L3zxAoTbKY8CEtJr 2A5AHO1rnzpsdFcHegQjHOkCFHNx7lFQST/SV5U+vMcXxsX/oC0f3OPwwL+Hg+mOC92g CbXP9pGbwGqB8mBlH+acFqjVz1jru3N+i2LXVfiJdyWKsWT7+uJyV0jVuMC4kZfwJT4f 1A== Received: from phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com (phxpaimrmta01.appoci.oracle.com [138.1.114.2]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 3y3t4fcxkc-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 15 May 2024 12:54:03 +0000 Received: from pps.filterd (phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com [127.0.0.1]) by phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com (8.17.1.19/8.17.1.19) with ESMTP id 44FB3H0j038357; Wed, 15 May 2024 12:54:02 GMT Received: from pps.reinject (localhost [127.0.0.1]) by phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com (PPS) with ESMTPS id 3y24pxgus7-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 15 May 2024 12:54:02 +0000 Received: from phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com (phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com [127.0.0.1]) by pps.reinject (8.17.1.5/8.17.1.5) with ESMTP id 44FCmlrg038458; Wed, 15 May 2024 12:54:02 GMT Received: from lab61.no.oracle.com (lab61.no.oracle.com [10.172.144.82]) by phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com (PPS) with ESMTP id 3y24pxgud9-4; Wed, 15 May 2024 12:54:01 +0000 From: =?UTF-8?q?H=C3=A5kon=20Bugge?= To: linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, rds-devel@oss.oracle.com Cc: Jason Gunthorpe , Leon Romanovsky , Saeed Mahameed , Tariq Toukan , "David S . Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Tejun Heo , Lai Jiangshan , Allison Henderson , Manjunath Patil , Mark Zhang , =?UTF-8?q?H=C3=A5kon=20Bugge?= , Chuck Lever , Shiraz Saleem , Yang Li Subject: [PATCH v2 3/6] RDMA/cma: Brute force GFP_NOIO Date: Wed, 15 May 2024 14:53:39 +0200 Message-Id: <20240515125342.1069999-4-haakon.bugge@oracle.com> X-Mailer: git-send-email 2.39.3 In-Reply-To: <20240515125342.1069999-1-haakon.bugge@oracle.com> References: <20240515125342.1069999-1-haakon.bugge@oracle.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1039,Hydra:6.0.650,FMLib:17.11.176.26 definitions=2024-05-15_06,2024-05-15_01,2023-05-22_02 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 bulkscore=0 adultscore=0 mlxscore=0 spamscore=0 phishscore=0 suspectscore=0 mlxlogscore=999 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2405010000 definitions=main-2405150090 X-Proofpoint-ORIG-GUID: oFChewOnUQFX9hbMFeg7JCRgZXWct7Wm X-Proofpoint-GUID: oFChewOnUQFX9hbMFeg7JCRgZXWct7Wm In cma_init(), we call memalloc_noio_{save,restore} in a parenthetic fashion when enabled by the module parameter force_noio. This in order to conditionally enable rdma_cm to work aligned with block I/O devices. Any work queued later on work-queues created during module initialization will inherit the PF_MEMALLOC_{NOIO,NOFS} flag(s), due to commit ("workqueue: Inherit NOIO and NOFS alloc flags"). We do this in order to enable ULPs using the RDMA stack to be used as a network block I/O device. This to support a filesystem on top of a raw block device which uses said ULP(s) and the RDMA stack as the network transport layer. Under intense memory pressure, we get memory reclaims. Assume the filesystem reclaims memory, goes to the raw block device, which calls into the ULP in question, which calls the RDMA stack. Now, if regular GFP_KERNEL allocations in the ULP or the RDMA stack require reclaims to be fulfilled, we end up in a circular dependency. We break this circular dependency by: 1. Force all allocations in the ULP and the relevant RDMA stack to use GFP_NOIO, by means of a parenthetic use of memalloc_noio_{save,restore} on all relevant entry points. 2. Make sure work-queues inherits current->flags wrt. PF_MEMALLOC_{NOIO,NOFS}, such that work executed on the work-queue inherits the same flag(s). Signed-off-by: HÃ¥kon Bugge --- drivers/infiniband/core/cma.c | 20 +++++++++++++++++--- 1 file changed, 17 insertions(+), 3 deletions(-) diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c index 1e2cd7c8716e8..23a50cc3e81cb 100644 --- a/drivers/infiniband/core/cma.c +++ b/drivers/infiniband/core/cma.c @@ -50,6 +50,10 @@ MODULE_LICENSE("Dual BSD/GPL"); #define CMA_IBOE_PACKET_LIFETIME 16 #define CMA_PREFERRED_ROCE_GID_TYPE IB_GID_TYPE_ROCE_UDP_ENCAP +static bool cma_force_noio; +module_param_named(force_noio, cma_force_noio, bool, 0444); +MODULE_PARM_DESC(force_noio, "Force the use of GFP_NOIO (Y/N)"); + static const char * const cma_events[] = { [RDMA_CM_EVENT_ADDR_RESOLVED] = "address resolved", [RDMA_CM_EVENT_ADDR_ERROR] = "address error", @@ -5424,6 +5428,10 @@ static struct pernet_operations cma_pernet_operations = { static int __init cma_init(void) { int ret; + unsigned int noio_flags; + + if (cma_force_noio) + noio_flags = memalloc_noio_save(); /* * There is a rare lock ordering dependency in cma_netdev_callback() @@ -5439,8 +5447,10 @@ static int __init cma_init(void) } cma_wq = alloc_ordered_workqueue("rdma_cm", WQ_MEM_RECLAIM); - if (!cma_wq) - return -ENOMEM; + if (!cma_wq) { + ret = -ENOMEM; + goto out; + } ret = register_pernet_subsys(&cma_pernet_operations); if (ret) @@ -5458,7 +5468,8 @@ static int __init cma_init(void) if (ret) goto err_ib; - return 0; + ret = 0; + goto out; err_ib: ib_unregister_client(&cma_client); @@ -5469,6 +5480,9 @@ static int __init cma_init(void) unregister_pernet_subsys(&cma_pernet_operations); err_wq: destroy_workqueue(cma_wq); +out: + if (cma_force_noio) + memalloc_noio_restore(noio_flags); return ret; } -- 2.45.0