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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A773EC3DA7D for ; Tue, 3 Jan 2023 17:50:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233724AbjACRuT (ORCPT ); Tue, 3 Jan 2023 12:50:19 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47270 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238142AbjACRuN (ORCPT ); Tue, 3 Jan 2023 12:50:13 -0500 Received: from mail-wr1-x42e.google.com (mail-wr1-x42e.google.com [IPv6:2a00:1450:4864:20::42e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3AC8E10BF for ; Tue, 3 Jan 2023 09:50:12 -0800 (PST) Received: by mail-wr1-x42e.google.com with SMTP id d9so1809363wrp.10 for ; Tue, 03 Jan 2023 09:50:12 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=TyYi4Jm2MdjvyDWb5zjv8Qzw0iEU31dCdMdvKdbQK0g=; b=fUJ8xNanL071cXbUvdWe4msB0sV2ETZzqkTxgI8rcJGbN8fz43Ac3FkotVyhf6LE/8 80sYxbm5BZ+Vl7cC2bO553m5uyp5d+cdEQkL+wz+UJZsnxfLbzhPvwnAx2u9NhdRNVB/ zdg+c3adZPbLgP/yVwZpLK42bKNzEl9svV9mio4niiGyj1ZrCqcO7PceOiJpivypwiEq cMpRyQif78iSjOxHoR4aZBquzOe0Afj8oHadnA3CkSPtXXyuir2ldflHpp3FlIa+11LU C39ApCl6Q9v7xsH1Q0BGZzs555ka6qYsUR+Ym/+yviFluyyOPa6M1luR37fXeWSfAowP kpcg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=TyYi4Jm2MdjvyDWb5zjv8Qzw0iEU31dCdMdvKdbQK0g=; b=J2xBYN4eYsuLdF85tbyQ2P/DVeUv/+g4TKNUNGjfQS3OU5++klZokvI5cAfvfsl+M3 2pVx2yNuCkCJ/rty88q7T/xzQE1zluwBErWaDnk0V4njxi9E819qX5qKQ6QxXuF64XvR zZ6T9OmccDqQBUToiRYeajd5fgo6Io62Tr8exrV0qQtXqwDmhjXmpwqZCUc+I5HhXKMn DOfC/DDl52GIUtDJwFtr693DTkewmuHgQUNds3QllejljimSuBivmJFKxhuTYlxtyMD3 40y4iFAbF+k1CvA5dnZ+CpjYPabwybsgk1LnEv+PL6J0IAOVDYc/qK/o3y5agxidZGXF 0RZg== X-Gm-Message-State: AFqh2kpY78GvIatrDw1kMAwK91OD5LWvQrqIXUPmxrN7QIL7H1rcrf+t TrlpoZ5t3Lz/kcHhIIVtb3A= X-Google-Smtp-Source: AMrXdXu1jUYyzGn58FFpX+lardEs6qySlMKy18QOaJja/qmX2K21PA5TetmYJ0AtHq/FVglTZmHx3w== X-Received: by 2002:a5d:554e:0:b0:271:fbdb:73d2 with SMTP id g14-20020a5d554e000000b00271fbdb73d2mr24495795wrw.12.1672768210805; Tue, 03 Jan 2023 09:50:10 -0800 (PST) Received: from localhost (host81-157-153-247.range81-157.btcentralplus.com. [81.157.153.247]) by smtp.gmail.com with ESMTPSA id h18-20020adfa4d2000000b00241cfa9333fsm32853921wrb.5.2023.01.03.09.50.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 03 Jan 2023 09:50:10 -0800 (PST) Date: Tue, 3 Jan 2023 17:50:09 +0000 From: Lorenzo Stoakes To: Fenghua Yu Cc: Vinod Koul , Dave Jiang , dmaengine@vger.kernel.org, Tony Zhu , Andrew Morton , linux-mm@kvack.org, Christoph Hellwig Subject: Re: [PATCH 09/17] mm: export access_remote_vm() symbol Message-ID: References: <20230103163505.1569356-1-fenghua.yu@intel.com> <20230103163505.1569356-10-fenghua.yu@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org On Tue, Jan 03, 2023 at 05:45:30PM +0000, Lorenzo Stoakes wrote: > Can you explain what use case you have for exporting this? Currently this is > only used by procfs. > Ugh I hit send too soon ! I see you've explained the _why_ (i.e. idxd). The other two points remain, however. > Additionally, it relies on a reference count being held on the mm which seems a > little risky exposing to a driver. > > Is there a reason you can't use access_process_vm() which is exported and > additionally handles the refrencing?