From patchwork Mon May 13 12:53:41 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Haakon Bugge X-Patchwork-Id: 13663421 Received: from mx0a-00069f02.pphosted.com (mx0a-00069f02.pphosted.com [205.220.165.32]) (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 91D1914C5A3; Mon, 13 May 2024 12:54:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=205.220.165.32 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715604880; cv=none; b=Xd52kQixgUbujxhsN9iDIwZpkjsyHjNr9P55EcL7uQ/Fnxw1L/IXM7MnPhN0t6t0KShQQwhYlFJaE6JPtr9M8V5Bpm+4fYxsnh7h/jVUXtI4PY19HRqIfANtfXzwoKvNPgbkbsKL/iPWL9hpBNJcVVqLRLDcT3GKSOyoKwiK9zc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715604880; c=relaxed/simple; bh=5Fu2t6pdCGvMZ87OXqyq9jKcjSje6VEv3PXJNmjruDE=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version:Content-Type; b=GfsGm+HtCXO931Hpd8Vm3AihuNPnaSlh8U9vu7yy9tsEd/nJO+laW8oTN5AAhFVf/5pYyDeWkkLyCfDf7G7ebAzPxZnxrGmNdEP9YsywYTQWSbvQ/8h7Y1kQ2Hl9dklVLZvF6oOiTmZXhnNOcDLN4UFccl3ixkh/+8IZWggc8cs= 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=GGCnjCCa; arc=none smtp.client-ip=205.220.165.32 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 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="GGCnjCCa" Received: from pps.filterd (m0333521.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 44DCY1Y7006201; Mon, 13 May 2024 12:54:18 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=QadSPCoRER7zNpX9ygLFAoFpDXIIuRTQdmDBorA2gZQ=; b=GGCnjCCaQ6DPQubMvAHWCbDsZf1pv+uss+vrmG9uZQlI0wV5n9/gIIF1SN239UFRqZdk sQep7I4pLCu/2UomBA0opAh4siAQ/9Ptb06kqgfcnspnLT3dLV6IxATGZbnSmDKEV+j7 Ge7JizlkVQhouAdj30KrP8+MeU65l7N53n2dKMqK+V3AbF0lNY3dm0+9ljkqbG87/35S JHS8mbx6iKsLpOWxy2kVHznVxqd8y0xHYBxWm8eUPLoXVWm6tcOzqfjvVSGJy8Uf6xt5 JAgLwfayjI7nz7wUwCOKjoZ73msTRiUUFFLe4EshZERh1qU7mStcJjVpP3zMmkzWbnv9 zQ== Received: from iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com (iadpaimrmta03.appoci.oracle.com [130.35.103.27]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 3y3jygr1gr-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 13 May 2024 12:54:18 +0000 Received: from pps.filterd (iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com [127.0.0.1]) by iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com (8.17.1.19/8.17.1.19) with ESMTP id 44DBG9uq018091; Mon, 13 May 2024 12:54:16 GMT Received: from pps.reinject (localhost [127.0.0.1]) by iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com (PPS) with ESMTPS id 3y1y4c136k-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 13 May 2024 12:54:16 +0000 Received: from iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com (iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com [127.0.0.1]) by pps.reinject (8.17.1.5/8.17.1.5) with ESMTP id 44DCq97x001819; Mon, 13 May 2024 12:54:16 GMT Received: from lab61.no.oracle.com (lab61.no.oracle.com [10.172.144.82]) by iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com (PPS) with ESMTP id 3y1y4c12sj-2; Mon, 13 May 2024 12:54:15 +0000 From: =?utf-8?q?H=C3=A5kon_Bugge?= 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_Bugge?= , Chuck Lever , Shiraz Saleem , Yang Li Subject: [PATCH 1/6] workqueue: Inherit NOIO and NOFS alloc flags Date: Mon, 13 May 2024 14:53:41 +0200 Message-Id: <20240513125346.764076-2-haakon.bugge@oracle.com> X-Mailer: git-send-email 2.39.3 In-Reply-To: <20240513125346.764076-1-haakon.bugge@oracle.com> References: <20240513125346.764076-1-haakon.bugge@oracle.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 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=2024-05-13_08,2024-05-10_02,2023-05-22_02 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 malwarescore=0 mlxlogscore=999 adultscore=0 mlxscore=0 spamscore=0 suspectscore=0 phishscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2405010000 definitions=main-2405130082 X-Proofpoint-ORIG-GUID: 6wYfbYVtkFvZ0tSeI9aBze7nBGESzq7w X-Proofpoint-GUID: 6wYfbYVtkFvZ0tSeI9aBze7nBGESzq7w For drivers/modules running inside a memalloc_{noio,nofs}_{save,restore} region, if a work-queue is created, we make sure work executed on the work-queue inherits the same flag(s). This in order to conditionally enable drivers to work aligned with block I/O devices. This commit makes sure that any work queued later on work-queues created during module initialization, when current's flags has PF_MEMALLOC_{NOIO,NOFS} set, will inherit the same flags. We do this in order to enable drivers to be used as a network block I/O device. This in order to support XFS or other file-systems on top of a raw block device which uses said drivers as the network transport layer. Under intense memory pressure, we get memory reclaims. Assume the file-system reclaims memory, goes to the raw block device, which calls into said drivers. Now, if regular GFP_KERNEL allocations in the drivers require reclaims to be fulfilled, we end up in a circular dependency. We break this circular dependency by: 1. Force all allocations in the drivers 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). That is what this commit contributes with. Signed-off-by: Håkon Bugge --- include/linux/workqueue.h | 2 ++ kernel/workqueue.c | 17 +++++++++++++++++ 2 files changed, 19 insertions(+) diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h index 158784dd189ab..09ecc692ffcae 100644 --- a/include/linux/workqueue.h +++ b/include/linux/workqueue.h @@ -398,6 +398,8 @@ enum wq_flags { __WQ_DRAINING = 1 << 16, /* internal: workqueue is draining */ __WQ_ORDERED = 1 << 17, /* internal: workqueue is ordered */ __WQ_LEGACY = 1 << 18, /* internal: create*_workqueue() */ + __WQ_NOIO = 1 << 19, /* internal: execute work with NOIO */ + __WQ_NOFS = 1 << 20, /* internal: execute work with NOFS */ /* BH wq only allows the following flags */ __WQ_BH_ALLOWS = WQ_BH | WQ_HIGHPRI, diff --git a/kernel/workqueue.c b/kernel/workqueue.c index d2dbe099286b9..a1d166a7c0f85 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -51,6 +51,7 @@ #include #include #include +#include #include #include #include @@ -3172,6 +3173,10 @@ __acquires(&pool->lock) unsigned long work_data; int lockdep_start_depth, rcu_start_depth; bool bh_draining = pool->flags & POOL_BH_DRAINING; + bool use_noio_allocs = pwq->wq->flags & __WQ_NOIO; + bool use_nofs_allocs = pwq->wq->flags & __WQ_NOFS; + unsigned long noio_flags; + unsigned long nofs_flags; #ifdef CONFIG_LOCKDEP /* * It is permissible to free the struct work_struct from @@ -3184,6 +3189,12 @@ __acquires(&pool->lock) lockdep_copy_map(&lockdep_map, &work->lockdep_map); #endif + /* Set inherited alloc flags */ + if (use_noio_allocs) + noio_flags = memalloc_noio_save(); + if (use_nofs_allocs) + nofs_flags = memalloc_nofs_save(); + /* ensure we're on the correct CPU */ WARN_ON_ONCE(!(pool->flags & POOL_DISASSOCIATED) && raw_smp_processor_id() != pool->cpu); @@ -3320,6 +3331,12 @@ __acquires(&pool->lock) /* must be the last step, see the function comment */ pwq_dec_nr_in_flight(pwq, work_data); + + /* Restore alloc flags */ + if (use_nofs_allocs) + memalloc_nofs_restore(nofs_flags); + if (use_noio_allocs) + memalloc_noio_restore(noio_flags); } /** From patchwork Mon May 13 12:53:42 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Haakon Bugge X-Patchwork-Id: 13663425 X-Patchwork-Delegate: kuba@kernel.org Received: from mx0a-00069f02.pphosted.com (mx0a-00069f02.pphosted.com [205.220.165.32]) (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 E3A1B1534F4; Mon, 13 May 2024 12:54:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=205.220.165.32 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715604891; cv=none; b=gypymViPqYa3fcxpnW0iXpouGQDTSyF6Uy8o7CSAHM4u+UEl+AA20uWLMtcy6MJ33Zyu3Y7UOMuEbiXCKBsUIqVrWAslEX8zl58ThrO7VwRK3Wio8bgYBzvjLgezNgFYaB/Hns8fW9tyoSpAZMUUM1K5wAlNnaey4NmQAtJOar4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715604891; c=relaxed/simple; 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Mon, 13 May 2024 12:54:20 GMT Received: from pps.reinject (localhost [127.0.0.1]) by iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com (PPS) with ESMTPS id 3y1y4c137y-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 13 May 2024 12:54:20 +0000 Received: from iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com (iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com [127.0.0.1]) by pps.reinject (8.17.1.5/8.17.1.5) with ESMTP id 44DCq982001819; Mon, 13 May 2024 12:54:20 GMT Received: from lab61.no.oracle.com (lab61.no.oracle.com [10.172.144.82]) by iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com (PPS) with ESMTP id 3y1y4c12sj-3; Mon, 13 May 2024 12:54:19 +0000 From: =?utf-8?q?H=C3=A5kon_Bugge?= 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_Bugge?= , Chuck Lever , Shiraz Saleem , Yang Li Subject: [PATCH 2/6] rds: Brute force GFP_NOIO Date: Mon, 13 May 2024 14:53:42 +0200 Message-Id: <20240513125346.764076-3-haakon.bugge@oracle.com> X-Mailer: git-send-email 2.39.3 In-Reply-To: <20240513125346.764076-1-haakon.bugge@oracle.com> References: <20240513125346.764076-1-haakon.bugge@oracle.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 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=2024-05-13_08,2024-05-10_02,2023-05-22_02 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 malwarescore=0 mlxlogscore=999 adultscore=0 mlxscore=0 spamscore=0 suspectscore=0 phishscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2405010000 definitions=main-2405130082 X-Proofpoint-ORIG-GUID: yQqe6sDAyaj4B4VhjcDdfWbca_tFey57 X-Proofpoint-GUID: yQqe6sDAyaj4B4VhjcDdfWbca_tFey57 X-Patchwork-Delegate: kuba@kernel.org For most entry points to RDS, we call memalloc_noio_{save,restore} in a parenthetic fashion when enabled by the module parameter force_noio. We skip the calls to memalloc_noio_{save,restore} in rds_ioctl(), as no memory allocations are executed in this function or its callees. The reason we execute memalloc_noio_{save,restore} in rds_poll(), is due to the following call chain: rds_poll() poll_wait() __pollwait() poll_get_entry() __get_free_page(GFP_KERNEL) The function rds_setsockopt() allocates memory in its callee's rds_get_mr() and rds_get_mr_for_dest(). Hence, we need memalloc_noio_{save,restore} in rds_setsockopt(). In rds_getsockopt(), we have rds_info_getsockopt() that allocates memory. Hence, we need memalloc_noio_{save,restore} in rds_getsockopt(). All the above, in order to conditionally enable RDS to become a block I/O device. Signed-off-by: Håkon Bugge --- net/rds/af_rds.c | 60 +++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 57 insertions(+), 3 deletions(-) diff --git a/net/rds/af_rds.c b/net/rds/af_rds.c index 8435a20968ef5..a89d192aabc0b 100644 --- a/net/rds/af_rds.c +++ b/net/rds/af_rds.c @@ -37,10 +37,16 @@ #include #include #include +#include #include #include "rds.h" +bool rds_force_noio; +EXPORT_SYMBOL(rds_force_noio); +module_param_named(force_noio, rds_force_noio, bool, 0444); +MODULE_PARM_DESC(force_noio, "Force the use of GFP_NOIO (Y/N)"); + /* this is just used for stats gathering :/ */ static DEFINE_SPINLOCK(rds_sock_lock); static unsigned long rds_sock_count; @@ -60,6 +66,10 @@ static int rds_release(struct socket *sock) { struct sock *sk = sock->sk; struct rds_sock *rs; + unsigned int noio_flags; + + if (rds_force_noio) + noio_flags = memalloc_noio_save(); if (!sk) goto out; @@ -90,6 +100,8 @@ static int rds_release(struct socket *sock) sock->sk = NULL; sock_put(sk); out: + if (rds_force_noio) + memalloc_noio_restore(noio_flags); return 0; } @@ -214,9 +226,13 @@ static __poll_t rds_poll(struct file *file, struct socket *sock, { struct sock *sk = sock->sk; struct rds_sock *rs = rds_sk_to_rs(sk); + unsigned int noio_flags; __poll_t mask = 0; unsigned long flags; + if (rds_force_noio) + noio_flags = memalloc_noio_save(); + poll_wait(file, sk_sleep(sk), wait); if (rs->rs_seen_congestion) @@ -249,6 +265,8 @@ static __poll_t rds_poll(struct file *file, struct socket *sock, if (mask) rs->rs_seen_congestion = 0; + if (rds_force_noio) + memalloc_noio_restore(noio_flags); return mask; } @@ -294,8 +312,12 @@ static int rds_cancel_sent_to(struct rds_sock *rs, sockptr_t optval, int len) { struct sockaddr_in6 sin6; struct sockaddr_in sin; + unsigned int noio_flags; int ret = 0; + if (rds_force_noio) + noio_flags = memalloc_noio_save(); + /* racing with another thread binding seems ok here */ if (ipv6_addr_any(&rs->rs_bound_addr)) { ret = -ENOTCONN; /* XXX not a great errno */ @@ -324,6 +346,8 @@ static int rds_cancel_sent_to(struct rds_sock *rs, sockptr_t optval, int len) rds_send_drop_to(rs, &sin6); out: + if (rds_force_noio) + noio_flags = memalloc_noio_save(); return ret; } @@ -485,8 +509,12 @@ static int rds_getsockopt(struct socket *sock, int level, int optname, { struct rds_sock *rs = rds_sk_to_rs(sock->sk); int ret = -ENOPROTOOPT, len; + unsigned int noio_flags; int trans; + if (rds_force_noio) + noio_flags = memalloc_noio_save(); + if (level != SOL_RDS) goto out; @@ -529,6 +557,8 @@ static int rds_getsockopt(struct socket *sock, int level, int optname, } out: + if (rds_force_noio) + memalloc_noio_restore(noio_flags); return ret; } @@ -538,12 +568,16 @@ static int rds_connect(struct socket *sock, struct sockaddr *uaddr, { struct sock *sk = sock->sk; struct sockaddr_in *sin; + unsigned int noio_flags; struct rds_sock *rs = rds_sk_to_rs(sk); int ret = 0; if (addr_len < offsetofend(struct sockaddr, sa_family)) return -EINVAL; + if (rds_force_noio) + noio_flags = memalloc_noio_save(); + lock_sock(sk); switch (uaddr->sa_family) { @@ -626,6 +660,8 @@ static int rds_connect(struct socket *sock, struct sockaddr *uaddr, } release_sock(sk); + if (rds_force_noio) + memalloc_noio_restore(noio_flags); return ret; } @@ -697,16 +733,28 @@ static int __rds_create(struct socket *sock, struct sock *sk, int protocol) static int rds_create(struct net *net, struct socket *sock, int protocol, int kern) { + unsigned int noio_flags; struct sock *sk; + int ret; if (sock->type != SOCK_SEQPACKET || protocol) return -ESOCKTNOSUPPORT; + if (rds_force_noio) + noio_flags = memalloc_noio_save(); + sk = sk_alloc(net, AF_RDS, GFP_KERNEL, &rds_proto, kern); - if (!sk) - return -ENOMEM; + if (!sk) { + ret = -ENOMEM; + goto out; + } - return __rds_create(sock, sk, protocol); + ret = __rds_create(sock, sk, protocol); +out: + if (rds_force_noio) + memalloc_noio_restore(noio_flags); + + return ret; } void rds_sock_addref(struct rds_sock *rs) @@ -895,8 +943,12 @@ u32 rds_gen_num; static int __init rds_init(void) { + unsigned int noio_flags; int ret; + if (rds_force_noio) + noio_flags = memalloc_noio_save(); + net_get_random_once(&rds_gen_num, sizeof(rds_gen_num)); ret = rds_bind_lock_init(); @@ -947,6 +999,8 @@ static int __init rds_init(void) out_bind: rds_bind_lock_destroy(); out: + if (rds_force_noio) + memalloc_noio_restore(noio_flags); return ret; } module_init(rds_init); From patchwork Mon May 13 12:53:43 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Haakon Bugge X-Patchwork-Id: 13663423 Received: from mx0a-00069f02.pphosted.com (mx0a-00069f02.pphosted.com [205.220.165.32]) (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 372091509BA; Mon, 13 May 2024 12:54:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=205.220.165.32 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715604883; cv=none; b=S9I1QJ4C40expJquo47WVc0xCjn7VsNQzRUj4H9J1EYrUBacjCdGIUvZ9tNgQZaLaouP11Ykyb7JdOzt42DgeRiwqDGo+cAH7O1vAqNRHJvbSnwNJ1hGqw2bEZ30ActlVCLN8+K0fGLA64MmMLSzjhGg/bv7/jkRGWDTJ6dzplg= ARC-Message-Signature: i=1; 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Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Tejun Heo , Lai Jiangshan , Allison Henderson , Manjunath Patil , Mark Zhang , =?utf-8?q?H=C3=A5kon_Bugge?= , Chuck Lever , Shiraz Saleem , Yang Li Subject: [PATCH 3/6] RDMA/cma: Brute force GFP_NOIO Date: Mon, 13 May 2024 14:53:43 +0200 Message-Id: <20240513125346.764076-4-haakon.bugge@oracle.com> X-Mailer: git-send-email 2.39.3 In-Reply-To: <20240513125346.764076-1-haakon.bugge@oracle.com> References: <20240513125346.764076-1-haakon.bugge@oracle.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 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=2024-05-13_08,2024-05-10_02,2023-05-22_02 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 malwarescore=0 mlxlogscore=999 adultscore=0 mlxscore=0 spamscore=0 suspectscore=0 phishscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2405010000 definitions=main-2405130082 X-Proofpoint-GUID: kyetM88yNMUg-WwcLsMwfkcfSGQcLT__ X-Proofpoint-ORIG-GUID: kyetM88yNMUg-WwcLsMwfkcfSGQcLT__ 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: Håkon 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); 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Mon, 13 May 2024 12:54:29 +0000 Received: from pps.filterd (iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com [127.0.0.1]) by iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com (8.17.1.19/8.17.1.19) with ESMTP id 44DBUHIJ018081; Mon, 13 May 2024 12:54:28 GMT Received: from pps.reinject (localhost [127.0.0.1]) by iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com (PPS) with ESMTPS id 3y1y4c13b1-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 13 May 2024 12:54:27 +0000 Received: from iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com (iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com [127.0.0.1]) by pps.reinject (8.17.1.5/8.17.1.5) with ESMTP id 44DCq988001819; Mon, 13 May 2024 12:54:27 GMT Received: from lab61.no.oracle.com (lab61.no.oracle.com [10.172.144.82]) by iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com (PPS) with ESMTP id 3y1y4c12sj-5; Mon, 13 May 2024 12:54:27 +0000 From: =?utf-8?q?H=C3=A5kon_Bugge?= 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_Bugge?= , Chuck Lever , Shiraz Saleem , Yang Li Subject: [PATCH 4/6] RDMA/cm: Brute force GFP_NOIO Date: Mon, 13 May 2024 14:53:44 +0200 Message-Id: <20240513125346.764076-5-haakon.bugge@oracle.com> X-Mailer: git-send-email 2.39.3 In-Reply-To: <20240513125346.764076-1-haakon.bugge@oracle.com> References: <20240513125346.764076-1-haakon.bugge@oracle.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 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=2024-05-13_08,2024-05-10_02,2023-05-22_02 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 malwarescore=0 mlxlogscore=999 adultscore=0 mlxscore=0 spamscore=0 suspectscore=0 phishscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2405010000 definitions=main-2405130082 X-Proofpoint-GUID: WgP0Gbq6W0_dadF2J4IoTaCH58UaEYGa X-Proofpoint-ORIG-GUID: WgP0Gbq6W0_dadF2J4IoTaCH58UaEYGa In ib_cm_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 ib_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 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: Håkon Bugge --- drivers/infiniband/core/cm.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) diff --git a/drivers/infiniband/core/cm.c b/drivers/infiniband/core/cm.c index 07fb8d3c037f0..767eec38eb57d 100644 --- a/drivers/infiniband/core/cm.c +++ b/drivers/infiniband/core/cm.c @@ -22,6 +22,7 @@ #include #include #include +#include #include #include @@ -35,6 +36,11 @@ MODULE_DESCRIPTION("InfiniBand CM"); MODULE_LICENSE("Dual BSD/GPL"); #define CM_DESTROY_ID_WAIT_TIMEOUT 10000 /* msecs */ + +static bool cm_force_noio; +module_param_named(force_noio, cm_force_noio, bool, 0444); +MODULE_PARM_DESC(force_noio, "Force the use of GFP_NOIO (Y/N)"); + static const char * const ibcm_rej_reason_strs[] = { [IB_CM_REJ_NO_QP] = "no QP", [IB_CM_REJ_NO_EEC] = "no EEC", @@ -4504,6 +4510,10 @@ static void cm_remove_one(struct ib_device *ib_device, void *client_data) static int __init ib_cm_init(void) { int ret; + unsigned int noio_flags; + + if (cm_force_noio) + noio_flags = memalloc_noio_save(); INIT_LIST_HEAD(&cm.device_list); rwlock_init(&cm.device_lock); @@ -4527,10 +4537,13 @@ static int __init ib_cm_init(void) if (ret) goto error3; - return 0; + goto error2; error3: destroy_workqueue(cm.wq); error2: + if (cm_force_noio) + memalloc_noio_restore(noio_flags); + return ret; } From patchwork Mon May 13 12:53:45 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Haakon Bugge X-Patchwork-Id: 13663439 Received: from mx0a-00069f02.pphosted.com (mx0a-00069f02.pphosted.com [205.220.165.32]) (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 7DECC14C5A3; Mon, 13 May 2024 12:58:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=205.220.165.32 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715605132; cv=none; b=j3ESkq/yYZ/mWgHUsityUreLzsAp0gfvTdZ9mh6C0ztM58jtumS6fFJzrfHRTRu/4+p5LBemEzIblYxpiMBfP+H17KXmq4OoDPzdna1oD1PMyu8+ID4CbzWJffF75RAXTSoLf8dZEhCW104h5m0Ptma/QpaJFeJLYAlnPSdUwnE= ARC-Message-Signature: i=1; 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Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Tejun Heo , Lai Jiangshan , Allison Henderson , Manjunath Patil , Mark Zhang , =?utf-8?q?H=C3=A5kon_Bugge?= , Chuck Lever , Shiraz Saleem , Yang Li Subject: [PATCH 5/6] RDMA/mlx5: Brute force GFP_NOIO Date: Mon, 13 May 2024 14:53:45 +0200 Message-Id: <20240513125346.764076-6-haakon.bugge@oracle.com> X-Mailer: git-send-email 2.39.3 In-Reply-To: <20240513125346.764076-1-haakon.bugge@oracle.com> References: <20240513125346.764076-1-haakon.bugge@oracle.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 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=2024-05-13_08,2024-05-10_02,2023-05-22_02 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 malwarescore=0 mlxlogscore=999 adultscore=0 mlxscore=0 spamscore=0 suspectscore=0 phishscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2405010000 definitions=main-2405130082 X-Proofpoint-GUID: TOhy9m6XdMDfEuxZjYPJolG0KLnVJM-D X-Proofpoint-ORIG-GUID: TOhy9m6XdMDfEuxZjYPJolG0KLnVJM-D In mlx5_ib_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 mlx5_ib to work aligned with 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 and the mlx5_ib driver 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 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: Håkon Bugge --- drivers/infiniband/hw/mlx5/main.c | 22 ++++++++++++++++++---- 1 file changed, 18 insertions(+), 4 deletions(-) diff --git a/drivers/infiniband/hw/mlx5/main.c b/drivers/infiniband/hw/mlx5/main.c index c2b557e642906..a424d518538ed 100644 --- a/drivers/infiniband/hw/mlx5/main.c +++ b/drivers/infiniband/hw/mlx5/main.c @@ -56,6 +56,10 @@ MODULE_AUTHOR("Eli Cohen "); MODULE_DESCRIPTION("Mellanox 5th generation network adapters (ConnectX series) IB driver"); MODULE_LICENSE("Dual BSD/GPL"); +static bool mlx5_ib_force_noio; +module_param_named(force_noio, mlx5_ib_force_noio, bool, 0444); +MODULE_PARM_DESC(force_noio, "Force the use of GFP_NOIO (Y/N)"); + struct mlx5_ib_event_work { struct work_struct work; union { @@ -4489,16 +4493,23 @@ static struct auxiliary_driver mlx5r_driver = { static int __init mlx5_ib_init(void) { + unsigned int noio_flags; int ret; + if (mlx5_ib_force_noio) + noio_flags = memalloc_noio_save(); + xlt_emergency_page = (void *)__get_free_page(GFP_KERNEL); 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Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Tejun Heo , Lai Jiangshan , Allison Henderson , Manjunath Patil , Mark Zhang , =?utf-8?q?H=C3=A5kon_Bugge?= , Chuck Lever , Shiraz Saleem , Yang Li Subject: [PATCH 6/6] net/mlx5: Brute force GFP_NOIO Date: Mon, 13 May 2024 14:53:46 +0200 Message-Id: <20240513125346.764076-7-haakon.bugge@oracle.com> X-Mailer: git-send-email 2.39.3 In-Reply-To: <20240513125346.764076-1-haakon.bugge@oracle.com> References: <20240513125346.764076-1-haakon.bugge@oracle.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 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=2024-05-13_08,2024-05-10_02,2023-05-22_02 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 malwarescore=0 mlxlogscore=999 adultscore=0 mlxscore=0 spamscore=0 suspectscore=0 phishscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2405010000 definitions=main-2405130082 X-Proofpoint-GUID: OPHdSHh1CF9xlBESd7cU_Sv3QGKIqKna X-Proofpoint-ORIG-GUID: OPHdSHh1CF9xlBESd7cU_Sv3QGKIqKna X-Patchwork-Delegate: kuba@kernel.org In mlx5_core_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 mlx5_core to work aligned with 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 and the mlx5_core driver 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 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: Håkon Bugge --- drivers/net/ethernet/mellanox/mlx5/core/main.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/mellanox/mlx5/core/main.c b/drivers/net/ethernet/mellanox/mlx5/core/main.c index 331ce47f51a17..aa1bf8bb5d15c 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/main.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/main.c @@ -48,6 +48,7 @@ #include #include #include +#include #include "mlx5_core.h" #include "lib/eq.h" #include "fs_core.h" @@ -87,6 +88,10 @@ static unsigned int prof_sel = MLX5_DEFAULT_PROF; module_param_named(prof_sel, prof_sel, uint, 0444); MODULE_PARM_DESC(prof_sel, "profile selector. Valid range 0 - 2"); +static bool mlx5_core_force_noio; +module_param_named(force_noio, mlx5_core_force_noio, bool, 0444); +MODULE_PARM_DESC(force_noio, "Force the use of GFP_NOIO (Y/N)"); + static u32 sw_owner_id[4]; #define MAX_SW_VHCA_ID (BIT(__mlx5_bit_sz(cmd_hca_cap_2, sw_vhca_id)) - 1) static DEFINE_IDA(sw_vhca_ida); @@ -2312,8 +2317,12 @@ static void mlx5_core_verify_params(void) static int __init mlx5_init(void) { + unsigned int noio_flags; int err; + if (mlx5_core_force_noio) + noio_flags = memalloc_noio_save(); + WARN_ONCE(strcmp(MLX5_ADEV_NAME, KBUILD_MODNAME), "mlx5_core name not in sync with kernel module name"); @@ -2334,7 +2343,7 @@ static int __init mlx5_init(void) if (err) goto err_pci; - return 0; + goto out; err_pci: mlx5_sf_driver_unregister(); @@ -2342,6 +2351,9 @@ static int __init mlx5_init(void) mlx5e_cleanup(); err_debug: mlx5_unregister_debugfs(); +out: + if (mlx5_core_force_noio) + memalloc_noio_restore(noio_flags); return err; }