From patchwork Mon Feb 22 15:23:20 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chuck Lever X-Patchwork-Id: 12098919 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A760DC433E6 for ; Mon, 22 Feb 2021 15:26:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6CF9464E57 for ; Mon, 22 Feb 2021 15:26:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231667AbhBVP0K (ORCPT ); Mon, 22 Feb 2021 10:26:10 -0500 Received: from mail.kernel.org ([198.145.29.99]:56732 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230512AbhBVPYE (ORCPT ); Mon, 22 Feb 2021 10:24:04 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id B5AAC64EDB; Mon, 22 Feb 2021 15:23:21 +0000 (UTC) Subject: [PATCH v2 3/4] SUNRPC: Refresh rq_pages using a bulk page allocator From: Chuck Lever To: mgorman@techsingularity.net Cc: linux-nfs@vger.kernel.org, linux-mm@kvack.org, kuba@kernel.org Date: Mon, 22 Feb 2021 10:23:20 -0500 Message-ID: <161400740085.195066.4366772800812293165.stgit@klimt.1015granger.net> In-Reply-To: <161400722731.195066.9584156841718557193.stgit@klimt.1015granger.net> References: <161400722731.195066.9584156841718557193.stgit@klimt.1015granger.net> User-Agent: StGit/1.0-5-g755c MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org Reduce the rate at which nfsd threads hammer on the page allocator. This improve throughput scalability by enabling the threads to run more independently of each other. Signed-off-by: Chuck Lever Reported-by: kernel test robot Reported-by: kernel test robot --- net/sunrpc/svc_xprt.c | 43 +++++++++++++++++++++++++++++++------------ 1 file changed, 31 insertions(+), 12 deletions(-) diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c index 819e46ab0a4a..15aacfa5ca21 100644 --- a/net/sunrpc/svc_xprt.c +++ b/net/sunrpc/svc_xprt.c @@ -661,11 +661,12 @@ static void svc_check_conn_limits(struct svc_serv *serv) static int svc_alloc_arg(struct svc_rqst *rqstp) { struct svc_serv *serv = rqstp->rq_server; + unsigned long needed; struct xdr_buf *arg; + struct page *page; int pages; int i; - /* now allocate needed pages. If we get a failure, sleep briefly */ pages = (serv->sv_max_mesg + 2 * PAGE_SIZE) >> PAGE_SHIFT; if (pages > RPCSVC_MAXPAGES) { pr_warn_once("svc: warning: pages=%u > RPCSVC_MAXPAGES=%lu\n", @@ -673,19 +674,28 @@ static int svc_alloc_arg(struct svc_rqst *rqstp) /* use as many pages as possible */ pages = RPCSVC_MAXPAGES; } - for (i = 0; i < pages ; i++) - while (rqstp->rq_pages[i] == NULL) { - struct page *p = alloc_page(GFP_KERNEL); - if (!p) { - set_current_state(TASK_INTERRUPTIBLE); - if (signalled() || kthread_should_stop()) { - set_current_state(TASK_RUNNING); - return -EINTR; - } - schedule_timeout(msecs_to_jiffies(500)); + + for (needed = 0, i = 0; i < pages ; i++) + if (!rqstp->rq_pages[i]) + needed++; + if (needed) { + LIST_HEAD(list); + +retry: + alloc_pages_bulk(GFP_KERNEL, 0, needed, &list); + for (i = 0; i < pages; i++) { + if (!rqstp->rq_pages[i]) { + page = list_first_entry_or_null(&list, + struct page, + lru); + if (unlikely(!page)) + goto empty_list; + list_del(&page->lru); + rqstp->rq_pages[i] = page; + needed--; } - rqstp->rq_pages[i] = p; } + } rqstp->rq_page_end = &rqstp->rq_pages[pages]; rqstp->rq_pages[pages] = NULL; /* this might be seen in nfsd_splice_actor() */ @@ -700,6 +710,15 @@ static int svc_alloc_arg(struct svc_rqst *rqstp) arg->len = (pages-1)*PAGE_SIZE; arg->tail[0].iov_len = 0; return 0; + +empty_list: + set_current_state(TASK_INTERRUPTIBLE); + if (signalled() || kthread_should_stop()) { + set_current_state(TASK_RUNNING); + return -EINTR; + } + schedule_timeout(msecs_to_jiffies(500)); + goto retry; } static bool