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=-3.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no 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 BBE10C433E0 for ; Tue, 9 Feb 2021 22:01:44 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 1BF3D64EB6 for ; Tue, 9 Feb 2021 22:01:44 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1BF3D64EB6 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id A2E226B006C; Tue, 9 Feb 2021 17:01:43 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 9DEC56B006E; Tue, 9 Feb 2021 17:01:43 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 8CD986B0070; Tue, 9 Feb 2021 17:01:43 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0180.hostedemail.com [216.40.44.180]) by kanga.kvack.org (Postfix) with ESMTP id 70D7E6B006C for ; Tue, 9 Feb 2021 17:01:43 -0500 (EST) Received: from smtpin07.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 3BED9824805A for ; Tue, 9 Feb 2021 22:01:43 +0000 (UTC) X-FDA: 77800102086.07.D3B8B7E Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf06.hostedemail.com (Postfix) with ESMTP id C5CF8C0001EA for ; Tue, 9 Feb 2021 22:01:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=iz8v7WB8rAGB4dR54Ek5r1ashQ2mtNeQY3DSOI1ePbM=; b=VcBQA8MMzx3QcTXwVmuTEW1jsd wYKfAMFZkSCiFIifea10qRixkxsFSHXIcCtHkkHR4Kea0GwOYmaDVzH0m7zDTNEmrrYSRbhgCLeyw u7IUcthEKP+N+V4ipaz22OBI1NMCZaquvSHvgClYMRbHW3kgNHxxqqMua1tRjwAGxNyMYkQoQ6Nnd iJ+d+SAUYVrP/fSMMo+cdTbOV7tkvoDR1lnPlsFRGQ1csKopW+5Ms6MCVSSwdjZ2Gp82C7WyoniGU ngKPbn9Q3J53KJ1u2gd34evnq9D13S1aMa0/o8wfePbebAub2Efvx3RwT1vRtCJjC5XEwh2MYpGfx TQx03e2w==; Received: from willy by casper.infradead.org with local (Exim 4.94 #2 (Red Hat Linux)) id 1l9b4Z-0080z9-0n; Tue, 09 Feb 2021 22:01:28 +0000 Date: Tue, 9 Feb 2021 22:01:27 +0000 From: Matthew Wilcox To: Chuck Lever Cc: "mgorman@suse.de" , "brouer@redhat.com" , Linux NFS Mailing List , "linux-mm@kvack.org" Subject: Re: Fwd: alloc_pages_bulk() Message-ID: <20210209220127.GB308988@casper.infradead.org> References: <2A0C36E7-8CB0-486F-A8DB-463CA28C5C5D@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: C5CF8C0001EA X-Stat-Signature: onxc5qeqk38hq6hdaus1bxek5uk8ftks Received-SPF: none (infradead.org>: No applicable sender policy available) receiver=imf06; identity=mailfrom; envelope-from=""; helo=casper.infradead.org; client-ip=90.155.50.34 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1612908101-566642 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: On Mon, Feb 08, 2021 at 05:50:51PM +0000, Chuck Lever wrote: > > We've been discussing how NFSD can more efficiently refill its > > receive buffers (currently alloc_page() in a loop; see > > net/sunrpc/svc_xprt.c::svc_alloc_arg()). I'm not familiar with the sunrpc architecture, but this feels like you're trying to optimise something that shouldn't exist. Ideally a write would ask the page cache for the pages that correspond to the portion of the file which is being written to. I appreciate that doesn't work well for, eg, NFS-over-TCP, but for NFS over any kind of RDMA, that should be possible, right?