From mboxrd@z Thu Jan 1 00:00:00 1970 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=-21.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 77381C433DB for ; Thu, 25 Mar 2021 11:43:44 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 15BF061974 for ; Thu, 25 Mar 2021 11:43:44 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 15BF061974 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=techsingularity.net Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id A1A866B007D; Thu, 25 Mar 2021 07:43:43 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 9CADD6B007E; Thu, 25 Mar 2021 07:43:43 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 86BDF6B0080; Thu, 25 Mar 2021 07:43:43 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0112.hostedemail.com [216.40.44.112]) by kanga.kvack.org (Postfix) with ESMTP id 6B2C06B007D for ; Thu, 25 Mar 2021 07:43:43 -0400 (EDT) Received: from smtpin10.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 298711DAD7 for ; Thu, 25 Mar 2021 11:43:43 +0000 (UTC) X-FDA: 77958211926.10.915EFBC Received: from outbound-smtp62.blacknight.com (outbound-smtp62.blacknight.com [46.22.136.251]) by imf21.hostedemail.com (Postfix) with ESMTP id 66996E000243 for ; Thu, 25 Mar 2021 11:43:41 +0000 (UTC) Received: from mail.blacknight.com (pemlinmail01.blacknight.ie [81.17.254.10]) by outbound-smtp62.blacknight.com (Postfix) with ESMTPS id 0BBB1FA82E for ; Thu, 25 Mar 2021 11:43:41 +0000 (GMT) Received: (qmail 18382 invoked from network); 25 Mar 2021 11:43:40 -0000 Received: from unknown (HELO stampy.112glenside.lan) (mgorman@techsingularity.net@[84.203.22.4]) by 81.17.254.9 with ESMTPA; 25 Mar 2021 11:43:40 -0000 From: Mel Gorman To: Andrew Morton Cc: Chuck Lever , Jesper Dangaard Brouer , Christoph Hellwig , Alexander Duyck , Vlastimil Babka , Matthew Wilcox , Ilias Apalodimas , LKML , Linux-Net , Linux-MM , Linux-NFS , Mel Gorman Subject: [PATCH 6/9] SUNRPC: Set rq_page_end differently Date: Thu, 25 Mar 2021 11:42:25 +0000 Message-Id: <20210325114228.27719-7-mgorman@techsingularity.net> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20210325114228.27719-1-mgorman@techsingularity.net> References: <20210325114228.27719-1-mgorman@techsingularity.net> MIME-Version: 1.0 X-Stat-Signature: r31o9qih5gwnm54m4ky9yqxoii61ya9d X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: 66996E000243 Received-SPF: none (techsingularity.net>: No applicable sender policy available) receiver=imf21; identity=mailfrom; envelope-from=""; helo=outbound-smtp62.blacknight.com; client-ip=46.22.136.251 X-HE-DKIM-Result: none/none X-HE-Tag: 1616672621-670734 Content-Transfer-Encoding: quoted-printable 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 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-rebas= e-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()"). Signed-off-by: Chuck Lever Signed-off-by: Mel Gorman --- net/sunrpc/svc_xprt.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c index 3cdd71a8df1e..609bda97d4ae 100644 --- a/net/sunrpc/svc_xprt.c +++ b/net/sunrpc/svc_xprt.c @@ -642,7 +642,7 @@ static void svc_check_conn_limits(struct svc_serv *se= rv) static int svc_alloc_arg(struct svc_rqst *rqstp) { struct svc_serv *serv =3D rqstp->rq_server; - struct xdr_buf *arg; + struct xdr_buf *arg =3D &rqstp->rq_arg; int pages; int i; =20 @@ -667,11 +667,10 @@ static int svc_alloc_arg(struct svc_rqst *rqstp) } rqstp->rq_pages[i] =3D p; } - rqstp->rq_page_end =3D &rqstp->rq_pages[i]; - rqstp->rq_pages[i++] =3D NULL; /* this might be seen in nfs_read_actor = */ + rqstp->rq_page_end =3D &rqstp->rq_pages[pages]; + rqstp->rq_pages[pages] =3D NULL; /* this might be seen in nfsd_splice_a= ctor() */ =20 /* Make arg->head point to first page and arg->pages point to rest */ - arg =3D &rqstp->rq_arg; arg->head[0].iov_base =3D page_address(rqstp->rq_pages[0]); arg->head[0].iov_len =3D PAGE_SIZE; arg->pages =3D rqstp->rq_pages + 1; --=20 2.26.2