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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id D6BC5C54EAA for ; Fri, 27 Jan 2023 00:20:13 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 380ED6B0072; Thu, 26 Jan 2023 19:20:13 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 3320C8E0002; Thu, 26 Jan 2023 19:20:13 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 1F83F6B0075; Thu, 26 Jan 2023 19:20:13 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id 0C3A46B0072 for ; Thu, 26 Jan 2023 19:20:13 -0500 (EST) Received: from smtpin03.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay04.hostedemail.com (Postfix) with ESMTP id DBED21A0350 for ; Fri, 27 Jan 2023 00:20:12 +0000 (UTC) X-FDA: 80398671864.03.8213508 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by imf06.hostedemail.com (Postfix) with ESMTP id 9BB49180006 for ; Fri, 27 Jan 2023 00:20:10 +0000 (UTC) Authentication-Results: imf06.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=DkTunwBp; dmarc=pass (policy=none) header.from=redhat.com; spf=pass (imf06.hostedemail.com: domain of david@redhat.com designates 170.10.133.124 as permitted sender) smtp.mailfrom=david@redhat.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1674778810; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=zhv1sJ/5W0UVM3IUaKfTJOk/lsk/OG7li8FezRc9IqY=; b=OPvXYko9OPCssThV4lveOlv2RzrYhHoUGB83+CYk/FmvZc/LxTzuikq4lqVx4NEn/PDXBV 48aWuPZyixXLiLGjUGynYo8IXg7LY39eMJ4wEv+9SLxxAW2yQ5MHzU88pqHiMUjZFbfpqH FyKdpCraYdwZWoTWJBSONtgAPdwQBaQ= ARC-Authentication-Results: i=1; imf06.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=DkTunwBp; dmarc=pass (policy=none) header.from=redhat.com; spf=pass (imf06.hostedemail.com: domain of david@redhat.com designates 170.10.133.124 as permitted sender) smtp.mailfrom=david@redhat.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1674778810; a=rsa-sha256; cv=none; b=fBezgWSdQt/wB8TC8lREyGp6JyakQDEBvakyZ+5m+qx1lCiJgWiGtm9kcvmjrdp4DbKOe7 akH0qO+FfksagMwAfvk+NFnfB8sWTbUp9VC7YadtCdOdk6NaOwvw9tXprYBQu9LR2Fefgv WjrWC0RlVcWS3LKPd/ir5ibb2iRBY+0= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1674778809; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=zhv1sJ/5W0UVM3IUaKfTJOk/lsk/OG7li8FezRc9IqY=; b=DkTunwBpJSYy9e1W7sU472ZkNv4MM0IFJWe1JsveDEugSr8Wd9Autzjn7MEykf4FjOuQBT AW4IFLMoce8iV6RPWEueK9r8xGgCBKn2kZAD9P572Mkfqg6eW2VL7Cwbf6VrSiDhQs69zC DOxYElIqYVP9pcuJM0tn7QuTOkB/taI= Received: from mail-wr1-f69.google.com (mail-wr1-f69.google.com [209.85.221.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_128_GCM_SHA256) id us-mta-482-DsaTBuRWMYafyof_IRCiEw-1; Thu, 26 Jan 2023 19:20:08 -0500 X-MC-Unique: DsaTBuRWMYafyof_IRCiEw-1 Received: by mail-wr1-f69.google.com with SMTP id j30-20020adfb31e000000b002be008be32cso600899wrd.13 for ; Thu, 26 Jan 2023 16:20:08 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:in-reply-to:subject:organization:from :references:cc:to:content-language:user-agent:mime-version:date :message-id:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=zhv1sJ/5W0UVM3IUaKfTJOk/lsk/OG7li8FezRc9IqY=; b=Yzs+PCp+AKSFftq2pE1c3+zX879gJn7ogSj/GBFHW/PjAIyF7LuJ1wIU73bfFMGE4B fsL6uGsu2jeT1ClKP3G+NZxbIQoQ/LHCLofPgl6dhVGPera6NjaEov1BkF3jzhA9omGG Dkv/Rc9bplM193v9KLoOnXo5ZmJrsG8WFX96xuaTt7cPuADcJAcNoKyNELZ9siodS3xp +YlHcwSTgI87eoIZg0CAUPwNSYA9ASoI0cL5LIIoVSZT8Age8X7xpschjiMyIuhVFvVH ws6cK1iaSIjGY/az6/+avE8oJQqJauR6NhS5S8cHNqYCUou8OlR+kFGbqgY1S7QWg8ne faHw== X-Gm-Message-State: AO0yUKU/CB1ZUuIZiJZEb0FixOggL4j7S9pZonZSOcZiY/byGmZiw7dQ 8z7J9AidPHF7tcBok5TkHkj774u78cdfeTP8CajK+4Q93qcA8CgwncWXrilnIOtdPJ9NjfkxVdx wM+mprp2Znt8= X-Received: by 2002:a05:600c:310c:b0:3dc:18de:b20d with SMTP id g12-20020a05600c310c00b003dc18deb20dmr9805071wmo.33.1674778807387; Thu, 26 Jan 2023 16:20:07 -0800 (PST) X-Google-Smtp-Source: AK7set+gxf09mnZS2txjdvCu5CPjJ98z7mHcuibpRYdj9hAoCYlhY/aoOQNZFqN0DCrStRv4arpcvw== X-Received: by 2002:a05:600c:310c:b0:3dc:18de:b20d with SMTP id g12-20020a05600c310c00b003dc18deb20dmr9805046wmo.33.1674778807122; Thu, 26 Jan 2023 16:20:07 -0800 (PST) Received: from ?IPV6:2003:cb:c707:5e00:9e97:86d:5ed5:bb95? (p200300cbc7075e009e97086d5ed5bb95.dip0.t-ipconnect.de. [2003:cb:c707:5e00:9e97:86d:5ed5:bb95]) by smtp.gmail.com with ESMTPSA id q18-20020a05600c2e5200b003d1de805de5sm2656808wmf.16.2023.01.26.16.20.05 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 26 Jan 2023 16:20:06 -0800 (PST) Message-ID: <3396eec4-a469-5b95-06db-c40e5616465b@redhat.com> Date: Fri, 27 Jan 2023 01:20:05 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.6.0 To: David Howells Cc: Al Viro , Christoph Hellwig , Matthew Wilcox , Jens Axboe , Jan Kara , Jeff Layton , Logan Gunthorpe , linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, Christoph Hellwig , John Hubbard , linux-mm@kvack.org References: <5a1796f3-e49c-80e8-2dd6-9a6e82939271@redhat.com> <7bbcccc9-6ebf-ffab-7425-2a12f217ba15@redhat.com> <246ba813-698b-8696-7f4d-400034a3380b@redhat.com> <20230120175556.3556978-1-dhowells@redhat.com> <20230120175556.3556978-3-dhowells@redhat.com> <3814749.1674474663@warthog.procyon.org.uk> <3903251.1674479992@warthog.procyon.org.uk> <2907560.1674777959@warthog.procyon.org.uk> From: David Hildenbrand Organization: Red Hat Subject: Re: [PATCH v7 2/8] iov_iter: Add a function to extract a page list from an iterator In-Reply-To: <2907560.1674777959@warthog.procyon.org.uk> X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspam-User: X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 9BB49180006 X-Stat-Signature: sgnye7e8yb1h3ejjmknjxdc8ahjzes83 X-HE-Tag: 1674778810-69907 X-HE-Meta: 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 bX3B1nrk 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 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 27.01.23 01:05, David Howells wrote: > David Hildenbrand wrote: > >> As raised already somewhere in the whole discussion by me, the right way to >> take such a long-term ping as vmsplice() does is to use >> FOLL_PIN|FOLL_LONGTERM. > > So the pipe infrastructure would have to be able to pin pages instead of > carrying refs on them? What about pages just allocated and added to the pipe > ring in normal pipe use? Ordinary kernel allocations (alloc_page() ...) always have to be freed via put_page() and friends. Such allocations are unmovable as default and don't require any special care. Pages mapped into user space are movable as default and might be placed on ZONE_MOVABLE/CMA memory (well, and might be swapped out). FOLL_LONGTERM makes sure to migrate these pages off of such problematic physical memory regions, such that we can safely pin them until eternity. -- Thanks, David / dhildenb