From patchwork Fri Apr 30 06:01:58 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Morton X-Patchwork-Id: 12232617 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=-20.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 568FAC433ED for ; Fri, 30 Apr 2021 06:02:01 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 07A8561424 for ; Fri, 30 Apr 2021 06:02:01 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 07A8561424 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 9CA4994004A; Fri, 30 Apr 2021 02:02:00 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 902FC940046; Fri, 30 Apr 2021 02:02:00 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 77D3F94004A; Fri, 30 Apr 2021 02:02:00 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0231.hostedemail.com [216.40.44.231]) by kanga.kvack.org (Postfix) with ESMTP id 52927940046 for ; Fri, 30 Apr 2021 02:02:00 -0400 (EDT) Received: from smtpin39.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 2404F180ACC20 for ; Fri, 30 Apr 2021 06:02:00 +0000 (UTC) X-FDA: 78087987600.39.B7F13EC Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf17.hostedemail.com (Postfix) with ESMTP id BEAB34080F5B for ; Fri, 30 Apr 2021 06:01:55 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id AA8C1613AD; Fri, 30 Apr 2021 06:01:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1619762519; bh=jfCA3DrrnjFCDrmOt6HauUBGUxKQ4tO/brGzf5Z+he4=; h=Date:From:To:Subject:In-Reply-To:From; b=FpZ01qOmQL8xS1tP3EPaiWHuAMqwySW5gIjxNElfjcqnajQnK1RafC4VdcxkSBrSl r4hbrjVUbOZ/N4vea9nFxrzsf05wQmJP8r/8NuTmOdYY1GybND+BPaUA0WIluZwLMN 1OYbRPLRYqSncnxiiWNfslNQtgCK0rIbQr70DgcQ= Date: Thu, 29 Apr 2021 23:01:58 -0700 From: Andrew Morton To: akpm@linux-foundation.org, alexander.duyck@gmail.com, alobakin@pm.me, brouer@redhat.com, chuck.lever@oracle.com, davem@davemloft.net, hch@infradead.org, ilias.apalodimas@linaro.org, linux-mm@kvack.org, mgorman@techsingularity.net, mm-commits@vger.kernel.org, torvalds@linux-foundation.org, vbabka@suse.cz, willy@infradead.org Subject: [patch 171/178] SUNRPC: set rq_page_end differently Message-ID: <20210430060158.L6Qo6kR9i%akpm@linux-foundation.org> In-Reply-To: <20210429225251.02b6386d21b69255b4f6c163@linux-foundation.org> User-Agent: s-nail v14.8.16 Authentication-Results: imf17.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=FpZ01qOm; dmarc=none; spf=pass (imf17.hostedemail.com: domain of akpm@linux-foundation.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org X-Rspamd-Server: rspam03 X-Stat-Signature: xf8uzhfxke1tyn3t5qtd7e1cxhk343a1 X-Rspamd-Queue-Id: BEAB34080F5B Received-SPF: none (linux-foundation.org>: No applicable sender policy available) receiver=imf17; identity=mailfrom; envelope-from=""; helo=mail.kernel.org; client-ip=198.145.29.99 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1619762515-106366 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: From: Chuck Lever Subject: SUNRPC: set rq_page_end differently Patch series "SUNRPC consumer for the bulk page allocator" This patch set and the measurements below are based on yesterday's bulk allocator series: git://git.kernel.org/pub/scm/linux/kernel/git/mel/linux.git mm-bulk-rebase-v5r9 The patches change SUNRPC to invoke the array-based bulk allocator instead of alloc_page(). The micro-benchmark results are promising. I ran a mixture of 256KB reads and writes over NFSv3. The server's kernel is built with KASAN enabled, so the comparison is exaggerated but I believe it is still valid. I instrumented svc_recv() to measure the latency of each call to svc_alloc_arg() and report it via a trace point. The following results are averages across the trace events. Single page: 25.007 us per call over 532,571 calls Bulk list: 6.258 us per call over 517,034 calls Bulk array: 4.590 us per call over 517,442 calls This patch (of 2) Refactor: I'm about to use the loop variable @i for something else. As far as the "i++" is concerned, that is a post-increment. The value of @i is not used subsequently, so the increment operator is unnecessary and can be removed. Also note that nfsd_read_actor() was renamed nfsd_splice_actor() by commit cf8208d0eabd ("sendfile: convert nfsd to splice_direct_to_actor()"). Link: https://lkml.kernel.org/r/20210325114228.27719-7-mgorman@techsingularity.net Signed-off-by: Chuck Lever Signed-off-by: Mel Gorman Reviewed-by: Alexander Lobakin Cc: Alexander Duyck Cc: Christoph Hellwig Cc: David Miller Cc: Ilias Apalodimas Cc: Jesper Dangaard Brouer Cc: Matthew Wilcox (Oracle) Cc: Vlastimil Babka Signed-off-by: Andrew Morton --- net/sunrpc/svc_xprt.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) --- a/net/sunrpc/svc_xprt.c~sunrpc-set-rq_page_end-differently +++ a/net/sunrpc/svc_xprt.c @@ -661,7 +661,7 @@ static void svc_check_conn_limits(struct static int svc_alloc_arg(struct svc_rqst *rqstp) { struct svc_serv *serv = rqstp->rq_server; - struct xdr_buf *arg; + struct xdr_buf *arg = &rqstp->rq_arg; int pages; int i; @@ -686,11 +686,10 @@ static int svc_alloc_arg(struct svc_rqst } rqstp->rq_pages[i] = p; } - rqstp->rq_page_end = &rqstp->rq_pages[i]; - rqstp->rq_pages[i++] = NULL; /* this might be seen in nfs_read_actor */ + rqstp->rq_page_end = &rqstp->rq_pages[pages]; + rqstp->rq_pages[pages] = NULL; /* this might be seen in nfsd_splice_actor() */ /* Make arg->head point to first page and arg->pages point to rest */ - arg = &rqstp->rq_arg; arg->head[0].iov_base = page_address(rqstp->rq_pages[0]); arg->head[0].iov_len = PAGE_SIZE; arg->pages = rqstp->rq_pages + 1;