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=-7.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 320D8C2BBCA for ; Mon, 14 Dec 2020 14:25:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F10572251F for ; Mon, 14 Dec 2020 14:25:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2440160AbgLNOXP (ORCPT ); Mon, 14 Dec 2020 09:23:15 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:20540 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2440154AbgLNOXG (ORCPT ); Mon, 14 Dec 2020 09:23:06 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1607955700; 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=uU+yqo3wknHZeTv4aPn0OoA1AQ4Jcrayd5ahcgSPHMs=; b=OH5jgKJ/BBDmFaBfWrkBPQlD9mmLCEKUHcwvxZTvZrVte5ztEjb0jtHeXqgt+gnMp4gsWR c5Fy9Gr+yOCfbfN05v5OAMCLDAGVqTAy/8yW66QNlWxHGPSt1/Hxy7Eg5jciYxZuvqK6Fm XZdNm5bNT9GeZEOe8MnubJ+3zNlikEQ= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-84-bGxr5615MoeqRRjCl0rFOA-1; Mon, 14 Dec 2020 09:21:36 -0500 X-MC-Unique: bGxr5615MoeqRRjCl0rFOA-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 6198D100B717; Mon, 14 Dec 2020 14:21:27 +0000 (UTC) Received: from [10.36.114.184] (ovpn-114-184.ams2.redhat.com [10.36.114.184]) by smtp.corp.redhat.com (Postfix) with ESMTP id D197018F0A; Mon, 14 Dec 2020 14:21:22 +0000 (UTC) Subject: Re: [PATCH v3 5/6] mm/gup: migrate pinned pages out of movable zone To: Jason Gunthorpe Cc: Pavel Tatashin , LKML , linux-mm , Andrew Morton , Vlastimil Babka , Michal Hocko , Oscar Salvador , Dan Williams , Sasha Levin , Tyler Hicks , Joonsoo Kim , mike.kravetz@oracle.com, Steven Rostedt , Ingo Molnar , Peter Zijlstra , Mel Gorman , Matthew Wilcox , David Rientjes , John Hubbard , Linux Doc Mailing List References: <20201211235005.GE5487@ziepe.ca> <2D10D596-3159-483C-81B4-CD187806ED46@redhat.com> <20201214133603.GF5487@ziepe.ca> From: David Hildenbrand Organization: Red Hat GmbH Message-ID: <69beec6b-8518-aa47-5a08-fd5f85cf9430@redhat.com> Date: Mon, 14 Dec 2020 15:21:21 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.4.0 MIME-Version: 1.0 In-Reply-To: <20201214133603.GF5487@ziepe.ca> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On 14.12.20 14:36, Jason Gunthorpe wrote: > On Sat, Dec 12, 2020 at 08:29:11AM +0100, David Hildenbrand wrote: > >>> Racing with another GUP in another thread is also not reasonable, so >>> failing to isolate can't be a failure >> >> Having VMs with multiple vfio containers is certainly realistic, and >> optimizing in user space to do vfio mappings concurrently doesn‘t >> sound too crazy to me. But I haven‘t checked if vfio common code >> already handles such concurrency. > > There is a lot more out there than vfio.. RDMA already does concurrent > pin_user_pages in real apps I actually misread your comment. I think we both agree that temporary isolation failures must not lead to a failure. -- Thanks, David / dhildenb