From patchwork Mon Feb 7 04:46:01 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: NeilBrown X-Patchwork-Id: 12736834 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id E68DAC433EF for ; Mon, 7 Feb 2022 04:48:49 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 87E3D6B0083; Sun, 6 Feb 2022 23:48:49 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 82CD66B0085; Sun, 6 Feb 2022 23:48:49 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 6A84A6B0088; Sun, 6 Feb 2022 23:48:49 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0207.hostedemail.com [216.40.44.207]) by kanga.kvack.org (Postfix) with ESMTP id 5B1546B0083 for ; Sun, 6 Feb 2022 23:48:49 -0500 (EST) Received: from smtpin25.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 1A48495271 for ; Mon, 7 Feb 2022 04:48:49 +0000 (UTC) X-FDA: 79114753578.25.A1E4322 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) by imf08.hostedemail.com (Postfix) with ESMTP id 95AC9160002 for ; Mon, 7 Feb 2022 04:48:48 +0000 (UTC) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 9A4A7210E8; Mon, 7 Feb 2022 04:48:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1644209327; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=NiDP9RcSA5ZHYXdBK498Y6AaH3rCTlt+B3aX1Ji9K8c=; b=yFQcY7p2U+yMBieYQ9Ap5kiuPCxStsoseCRC/zR9E8aD0xHJbjesBUcCSH2xeK28Xr+qra dBFVvzDjLz+SJR7Iz4DHuuW4NfNXt/7NY9lNVgM8wxG8miIeReC8BtVti8+5AsmJdOPQjI qhhGKn3Dig0Sw1MKlQQ6CBz1NZmWp3I= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1644209327; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=NiDP9RcSA5ZHYXdBK498Y6AaH3rCTlt+B3aX1Ji9K8c=; b=aKDca+HVCXocFEMyCBbTi5HaOEdAbBSDpju6By0CvJgdLM20DtD9hw8g8NZToqQcESJ+Hg g/+Hg4IWfhZVLSAA== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 9D0F91330E; Mon, 7 Feb 2022 04:48:44 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id WBpCFqykAGKKNQAAMHmgww (envelope-from ); Mon, 07 Feb 2022 04:48:44 +0000 Subject: [PATCH 17/21] SUNRPC: improve 'swap' handling: scheduling and PF_MEMALLOC From: NeilBrown To: Trond Myklebust , Anna Schumaker , Chuck Lever , Andrew Morton , Mark Hemment , Christoph Hellwig , David Howells Cc: linux-nfs@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Date: Mon, 07 Feb 2022 15:46:01 +1100 Message-ID: <164420916122.29374.8760841832230503670.stgit@noble.brown> In-Reply-To: <164420889455.29374.17958998143835612560.stgit@noble.brown> References: <164420889455.29374.17958998143835612560.stgit@noble.brown> User-Agent: StGit/0.23 MIME-Version: 1.0 X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 95AC9160002 X-Stat-Signature: mn6nbpqfa5eqizufy4mkaj5kc8um368c Authentication-Results: imf08.hostedemail.com; dkim=pass header.d=suse.de header.s=susede2_rsa header.b=yFQcY7p2; dkim=pass header.d=suse.de header.s=susede2_ed25519 header.b=aKDca+HV; dmarc=pass (policy=none) header.from=suse.de; spf=pass (imf08.hostedemail.com: domain of neilb@suse.de designates 195.135.220.28 as permitted sender) smtp.mailfrom=neilb@suse.de X-Rspam-User: nil X-HE-Tag: 1644209328-578 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: rpc tasks can be marked as RPC_TASK_SWAPPER. This causes GFP_MEMALLOC to be used for some allocations. This is needed in some cases, but not in all where it is currently provided, and in some where it isn't provided. Currently *all* tasks associated with a rpc_client on which swap is enabled get the flag and hence some GFP_MEMALLOC support. GFP_MEMALLOC is provided for ->buf_alloc() but only swap-writes need it. However xdr_alloc_bvec does not get GFP_MEMALLOC - though it often does need it. xdr_alloc_bvec is called while the XPRT_LOCK is held. If this blocks, then it blocks all other queued tasks. So this allocation needs GFP_MEMALLOC for *all* requests, not just writes, when the xprt is used for any swap writes. Similarly, if the transport is not connected, that will block all requests including swap writes, so memory allocations should get GFP_MEMALLOC if swap writes are possible. So with this patch: 1/ we ONLY set RPC_TASK_SWAPPER for swap writes. 2/ __rpc_execute() sets PF_MEMALLOC while handling any task with RPC_TASK_SWAPPER set, or when handling any task that holds the XPRT_LOCKED lock on an xprt used for swap. This removes the need for the RPC_IS_SWAPPER() test in ->buf_alloc handlers. 3/ xprt_prepare_transmit() sets PF_MEMALLOC after locking any task to a swapper xprt. __rpc_execute() will clear it. 3/ PF_MEMALLOC is set for all the connect workers. Signed-off-by: NeilBrown Reviewed-by: Chuck Lever --- fs/nfs/write.c | 2 ++ net/sunrpc/clnt.c | 2 -- net/sunrpc/sched.c | 20 +++++++++++++++++--- net/sunrpc/xprt.c | 3 +++ net/sunrpc/xprtrdma/transport.c | 6 ++++-- net/sunrpc/xprtsock.c | 8 ++++++++ 6 files changed, 34 insertions(+), 7 deletions(-) diff --git a/fs/nfs/write.c b/fs/nfs/write.c index 987a187bd39a..9f7176745fef 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -1409,6 +1409,8 @@ static void nfs_initiate_write(struct nfs_pgio_header *hdr, { int priority = flush_task_priority(how); + if (IS_SWAPFILE(hdr->inode)) + task_setup_data->flags |= RPC_TASK_SWAPPER; task_setup_data->priority = priority; rpc_ops->write_setup(hdr, msg, &task_setup_data->rpc_client); trace_nfs_initiate_write(hdr); diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c index d1fb7c0c7685..842366a2fc57 100644 --- a/net/sunrpc/clnt.c +++ b/net/sunrpc/clnt.c @@ -1085,8 +1085,6 @@ void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt) task->tk_flags |= RPC_TASK_TIMEOUT; if (clnt->cl_noretranstimeo) task->tk_flags |= RPC_TASK_NO_RETRANS_TIMEOUT; - if (atomic_read(&clnt->cl_swapper)) - task->tk_flags |= RPC_TASK_SWAPPER; /* Add to the client's list of all tasks */ spin_lock(&clnt->cl_lock); list_add_tail(&task->tk_task, &clnt->cl_tasks); diff --git a/net/sunrpc/sched.c b/net/sunrpc/sched.c index 256302bf6557..9020cedb7c95 100644 --- a/net/sunrpc/sched.c +++ b/net/sunrpc/sched.c @@ -869,6 +869,15 @@ void rpc_release_calldata(const struct rpc_call_ops *ops, void *calldata) ops->rpc_release(calldata); } +static bool xprt_needs_memalloc(struct rpc_xprt *xprt, struct rpc_task *tk) +{ + if (!xprt) + return false; + if (!atomic_read(&xprt->swapper)) + return false; + return test_bit(XPRT_LOCKED, &xprt->state) && xprt->snd_task == tk; +} + /* * This is the RPC `scheduler' (or rather, the finite state machine). */ @@ -877,6 +886,7 @@ static void __rpc_execute(struct rpc_task *task) struct rpc_wait_queue *queue; int task_is_async = RPC_IS_ASYNC(task); int status = 0; + unsigned long pflags = current->flags; WARN_ON_ONCE(RPC_IS_QUEUED(task)); if (RPC_IS_QUEUED(task)) @@ -899,6 +909,10 @@ static void __rpc_execute(struct rpc_task *task) } if (!do_action) break; + if (RPC_IS_SWAPPER(task) || + xprt_needs_memalloc(task->tk_xprt, task)) + current->flags |= PF_MEMALLOC; + trace_rpc_task_run_action(task, do_action); do_action(task); @@ -936,7 +950,7 @@ static void __rpc_execute(struct rpc_task *task) rpc_clear_running(task); spin_unlock(&queue->lock); if (task_is_async) - return; + goto out; /* sync task: sleep here */ trace_rpc_task_sync_sleep(task, task->tk_action); @@ -960,6 +974,8 @@ static void __rpc_execute(struct rpc_task *task) /* Release all resources associated with the task */ rpc_release_task(task); +out: + current_restore_flags(pflags, PF_MEMALLOC); } /* @@ -1018,8 +1034,6 @@ int rpc_malloc(struct rpc_task *task) if (RPC_IS_ASYNC(task)) gfp = GFP_NOWAIT | __GFP_NOWARN; - if (RPC_IS_SWAPPER(task)) - gfp |= __GFP_MEMALLOC; size += sizeof(struct rpc_buffer); if (size <= RPC_BUFFER_MAXSIZE) diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c index a0a2583fe941..0614e7463d4b 100644 --- a/net/sunrpc/xprt.c +++ b/net/sunrpc/xprt.c @@ -1492,6 +1492,9 @@ bool xprt_prepare_transmit(struct rpc_task *task) return false; } + if (atomic_read(&xprt->swapper)) + /* This will be clear in __rpc_execute */ + current->flags |= PF_MEMALLOC; return true; } diff --git a/net/sunrpc/xprtrdma/transport.c b/net/sunrpc/xprtrdma/transport.c index 923e4b512ee9..6b7e10e5a141 100644 --- a/net/sunrpc/xprtrdma/transport.c +++ b/net/sunrpc/xprtrdma/transport.c @@ -235,8 +235,11 @@ xprt_rdma_connect_worker(struct work_struct *work) struct rpcrdma_xprt *r_xprt = container_of(work, struct rpcrdma_xprt, rx_connect_worker.work); struct rpc_xprt *xprt = &r_xprt->rx_xprt; + unsigned int pflags = current->flags; int rc; + if (atomic_read(&xprt->swapper)) + current->flags |= PF_MEMALLOC; rc = rpcrdma_xprt_connect(r_xprt); xprt_clear_connecting(xprt); if (!rc) { @@ -250,6 +253,7 @@ xprt_rdma_connect_worker(struct work_struct *work) rpcrdma_xprt_disconnect(r_xprt); xprt_unlock_connect(xprt, r_xprt); xprt_wake_pending_tasks(xprt, rc); + current_restore_flags(pflags, PF_MEMALLOC); } /** @@ -572,8 +576,6 @@ xprt_rdma_allocate(struct rpc_task *task) flags = RPCRDMA_DEF_GFP; if (RPC_IS_ASYNC(task)) flags = GFP_NOWAIT | __GFP_NOWARN; - if (RPC_IS_SWAPPER(task)) - flags |= __GFP_MEMALLOC; if (!rpcrdma_check_regbuf(r_xprt, req->rl_sendbuf, rqst->rq_callsize, flags)) diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c index 69b6ee5a5fd1..c461a0ce9531 100644 --- a/net/sunrpc/xprtsock.c +++ b/net/sunrpc/xprtsock.c @@ -2047,7 +2047,10 @@ static void xs_udp_setup_socket(struct work_struct *work) struct rpc_xprt *xprt = &transport->xprt; struct socket *sock; int status = -EIO; + unsigned int pflags = current->flags; + if (atomic_read(&xprt->swapper)) + current->flags |= PF_MEMALLOC; sock = xs_create_sock(xprt, transport, xs_addr(xprt)->sa_family, SOCK_DGRAM, IPPROTO_UDP, false); @@ -2067,6 +2070,7 @@ static void xs_udp_setup_socket(struct work_struct *work) xprt_clear_connecting(xprt); xprt_unlock_connect(xprt, transport); xprt_wake_pending_tasks(xprt, status); + current_restore_flags(pflags, PF_MEMALLOC); } /** @@ -2226,7 +2230,10 @@ static void xs_tcp_setup_socket(struct work_struct *work) struct socket *sock = transport->sock; struct rpc_xprt *xprt = &transport->xprt; int status; + unsigned int pflags = current->flags; + if (atomic_read(&xprt->swapper)) + current->flags |= PF_MEMALLOC; if (!sock) { sock = xs_create_sock(xprt, transport, xs_addr(xprt)->sa_family, SOCK_STREAM, @@ -2291,6 +2298,7 @@ static void xs_tcp_setup_socket(struct work_struct *work) xprt_clear_connecting(xprt); out_unlock: xprt_unlock_connect(xprt, transport); + current_restore_flags(pflags, PF_MEMALLOC); } /**