Received: by 2002:a05:6358:3188:b0:123:57c1:9b43 with SMTP id q8csp2111642rwd; Fri, 26 May 2023 01:43:41 -0700 (PDT) X-Google-Smtp-Source: ACHHUZ5Sb2CwiV/3GBP7ry8mr5ZyxD3zO8BHCusxtb/nd4n7rVKhBIgkT34Z+DVbWr5QhtKGfSLd X-Received: by 2002:a05:6a20:1449:b0:10c:8e0f:7b19 with SMTP id a9-20020a056a20144900b0010c8e0f7b19mr1492348pzi.57.1685090620928; Fri, 26 May 2023 01:43:40 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1685090620; cv=none; d=google.com; s=arc-20160816; b=acR3vBDlK+uekVbtCpr8psDm84GzwJtbC71ToZWwWAuKMif74devkJ4B3E/RJOW2ql nepoVWmBI1e6pY1RqS7dgPdVyrmSmzvx17CMRjw3rr5s9w6AFsCCR+crL4k7TrFLWTqu fnWHsDNaG9uh/sQmHLBNdta+BPlMGHHkXQ/2ZZgtSCchlYUro6v4HushuMoYeXyYOFlY ZbQg+b7C40hqeqenT4rXiOTMaZxuEX+mGElccwA/wOHqboZrsvC5WCE4qh22hidGtFNK Cm3ETYhLaGTaPzaZLjWaabFlpkMwiJ1hbhB3B1iXKPNwx0in/5saOe1T45Wkc8AiGssp HueA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:message-id:date:content-id:mime-version:subject :cc:to:references:in-reply-to:from:organization:dkim-signature; bh=c892gmHnFnyJknfSVBWfjI1O+CRXJGRWy+yybVQO/8A=; b=vV9DPNsO1yosT4MJSzIHe5d6ukhA0HvQjhPRm7lk1Mah4UjJXuEHsVVluj1zDjjrJd TRb7djAwLq9Y+zteR4ZOKRLdYca1l4K+0Ku2hIMYk2/zW9wdSLdiiZ95+yWwV0ziRzZh kQ/kmyMeqjAB0HsL32D8XWsYP5jh29OwevEGFlRdJxNHFJzbhl+/a0NpLMVDPnpO1tsy T1iafXpCw+fOJHgzRSl+pMSq1hrLm24uqlUwaa2V9nyKHOFhK5CPX0WdmfCOKF3mz7Qp F1S5mXITQ362TcsqjUVsrvr4jmo8h/O2lGReikwcY8RYoLV6KMm4fuyPw+4rug6uwxSU IpHw== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@redhat.com header.s=mimecast20190719 header.b=cFhpiHDK; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=redhat.com Return-Path: Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id q22-20020a637516000000b0052d7238ad55si3106077pgc.793.2023.05.26.01.43.28; Fri, 26 May 2023 01:43:40 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@redhat.com header.s=mimecast20190719 header.b=cFhpiHDK; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=redhat.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242672AbjEZIaR (ORCPT + 99 others); Fri, 26 May 2023 04:30:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34732 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242661AbjEZIaL (ORCPT ); Fri, 26 May 2023 04:30:11 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4AC5619C for ; Fri, 26 May 2023 01:29:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1685089769; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=c892gmHnFnyJknfSVBWfjI1O+CRXJGRWy+yybVQO/8A=; b=cFhpiHDKvo2x30cHJRaNGprlQFTAO3McevsP04WM2OfEZqoTAc0i9aD3LH08lgvX+O2vDB 0oygoi+qFsh4WfDggal4J31geI6S76sVDWNqYBLo/CUzhGCNxJzv1sSjEUD6dx4qho6Vir DdeQMiZ/GxHHva9iqa6Y/50qcKnfOh4= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-436-bQLEo4I9MN6xV7hqaz2Y0Q-1; Fri, 26 May 2023 04:29:24 -0400 X-MC-Unique: bQLEo4I9MN6xV7hqaz2Y0Q-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 0A07538035A6; Fri, 26 May 2023 08:29:24 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.39.192.68]) by smtp.corp.redhat.com (Postfix) with ESMTP id 6C9D19D7A; Fri, 26 May 2023 08:29:20 +0000 (UTC) Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 From: David Howells In-Reply-To: References: <20230525223953.225496-1-dhowells@redhat.com> <20230525223953.225496-2-dhowells@redhat.com> To: Christoph Hellwig Cc: dhowells@redhat.com, David Hildenbrand , Jens Axboe , Al Viro , Matthew Wilcox , Jan Kara , Jeff Layton , Jason Gunthorpe , Logan Gunthorpe , Hillf Danton , Christian Brauner , Linus Torvalds , linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Andrew Morton Subject: Re: [RFC PATCH v2 1/3] mm: Don't pin ZERO_PAGE in pin_user_pages() MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <520321.1685089759.1@warthog.procyon.org.uk> Date: Fri, 26 May 2023 09:29:19 +0100 Message-ID: <520322.1685089759@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 3.1 on 10.11.54.5 X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE, SPF_HELO_NONE,SPF_NONE,T_SCC_BODY_TEXT_LINE autolearn=unavailable autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Christoph Hellwig wrote: > Shouldn't unpin_user_pages It calls gup_put_folio() which is where the skip is. > and bio_release_page also be updated to skip a zero page here? Porbably best to leave it to unpin_user_page() there. I've tried to hide the behaviour entirely within gup.c. David