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=-2.5 required=3.0 tests=MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_MUTT autolearn=ham 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 DE2A9C04E84 for ; Tue, 28 May 2019 09:08:26 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id A291F208CB for ; Tue, 28 May 2019 09:08:26 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A291F208CB Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 222316B0275; Tue, 28 May 2019 05:08:26 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 1D1776B0276; Tue, 28 May 2019 05:08:26 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0C3376B0278; Tue, 28 May 2019 05:08:26 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from mail-ed1-f71.google.com (mail-ed1-f71.google.com [209.85.208.71]) by kanga.kvack.org (Postfix) with ESMTP id B50A96B0275 for ; Tue, 28 May 2019 05:08:25 -0400 (EDT) Received: by mail-ed1-f71.google.com with SMTP id x16so32106456edm.16 for ; Tue, 28 May 2019 02:08:25 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-original-authentication-results:x-gm-message-state:date:from:to :cc:subject:message-id:references:mime-version:content-disposition :in-reply-to:user-agent; bh=ZwcWr9VWmfqG3HHy672VEg4BSNiSaWATEy9aAwdElOM=; b=jBRLm3TiU+j5x8n0r0WkPJW2d8xrRof5MSyjU9ug9+YUHRfUVUwm2LJRIzsP0yXZAy pUPBNCRa1C8AhS+HRafwt/Bg4Euchf6y1rDaV46a1x3fcaOaP6QCbgxdhrz9z7LC6fg9 HapZx0V9hLf2beBiwNVe5pxDVW4LTt+e+aSdHlI/VaLOJcwooW6t9SUFE1eXJUMsdjYg f6a87zFseHZP717sSeu3nlEczQVdcyKs/1qlcGin6PXXOTIWtmFfnSVVMLu43LXtirTy jk5cGMCMvxjT+VBC0igBnvAvyovQBRKJlPIYncArfgt/5gwYQOIWyM+o2VS5hfjovzb2 wAFA== X-Original-Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning mhocko@kernel.org does not designate 195.135.220.15 as permitted sender) smtp.mailfrom=mhocko@kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=kernel.org X-Gm-Message-State: APjAAAXZQu3lrDBo6twodjwIRU93ooG8evvrfABP7pqxvIzVJOH3+N8C yaPIsOfajquk9Vs+Vld+x2TnFvvv9KVxPisG/VsXuEdT0QoV0FOTIgkhwE3Ni2MK4ymUZGZcrYo vSQPBv8ZgDjvmwWdm2dXsS91pctEz7gDnXZeruxPR3NcOa/ClhwXdE681ieVmtgc= X-Received: by 2002:a50:991d:: with SMTP id k29mr126632963edb.29.1559034505323; Tue, 28 May 2019 02:08:25 -0700 (PDT) X-Google-Smtp-Source: APXvYqxlcQLV4daaAzq6jxmErEHhO22CINRJgG+IMBdtBjgxN638/UQVtAiIOE9WEeFS2m2DYzpf X-Received: by 2002:a50:991d:: with SMTP id k29mr126632880edb.29.1559034504383; Tue, 28 May 2019 02:08:24 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1559034504; cv=none; d=google.com; s=arc-20160816; b=eSnEXHXBxmgzjIiba9HD+m0LFflGmB8I0cIxkbuZ1odroVqOWttczQTupvcbEBANxO q0NFhAGbzBKwHZOnJ8N8EbxuLcwHGe7uS0KaJyS31WAqb2ZNGxuixYaitmvmmNAjRkG2 rheAQzmTMaRli64tw3nR7ROEvql22cjjiU/bfki/k+Hu9Y1seUwJFMbH8cbP/QJcxObn 3Z9/RfVOO80kBdAt05lguDokuWTEEI/dmpiVL2zESODdJg8GRuRUKnCGA5ajOyJ7BURf Pmm3W6QjNPeO4G6mY1WOeSvK6HQufHQvLTv4L2a97eXpm9t3YeJWkBaBhpkKbVnjjLm3 nquw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=user-agent:in-reply-to:content-disposition:mime-version:references :message-id:subject:cc:to:from:date; bh=ZwcWr9VWmfqG3HHy672VEg4BSNiSaWATEy9aAwdElOM=; b=CtXDPxD+cWSrRDGpLaNSCSsEkmRk8EC1BzDZ+HbHSbTfudN2l/M27Vh0pSKqQ3z3IL HiM6yItb48q6ObvznFTETswgxOxfFmwLSRqi/eaGkvo8znty2EZgenAqONSu3ziLngdE cWGjDDruhAbFW6VOY7AQ4v+8c69mqfdRJb1/ImWPrYQZOK+z0Yz9gmay+JcDUcDOOszm hv980qKE58XZI0BS11psRIZ9R+xCd0CpTgi+VdNI5PW6Ibho6mfCZywEB6JaF8yDrNEz /ctUsECmfN00PIhCJPhW60Si15ZOc89bJI2WOwA/1PXP03JkqdPePSfamwPaO9tYUpRz hlKQ== ARC-Authentication-Results: i=1; mx.google.com; spf=softfail (google.com: domain of transitioning mhocko@kernel.org does not designate 195.135.220.15 as permitted sender) smtp.mailfrom=mhocko@kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: from mx1.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id h58si9192967eda.50.2019.05.28.02.08.24 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 28 May 2019 02:08:24 -0700 (PDT) Received-SPF: softfail (google.com: domain of transitioning mhocko@kernel.org does not designate 195.135.220.15 as permitted sender) client-ip=195.135.220.15; Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning mhocko@kernel.org does not designate 195.135.220.15 as permitted sender) smtp.mailfrom=mhocko@kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=kernel.org X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 784DAB010; Tue, 28 May 2019 09:08:23 +0000 (UTC) Date: Tue, 28 May 2019 11:08:21 +0200 From: Michal Hocko To: Minchan Kim Cc: Daniel Colascione , Andrew Morton , LKML , linux-mm , Johannes Weiner , Tim Murray , Joel Fernandes , Suren Baghdasaryan , Shakeel Butt , Sonny Rao , Brian Geffon , Linux API Subject: Re: [RFC 7/7] mm: madvise support MADV_ANONYMOUS_FILTER and MADV_FILE_FILTER Message-ID: <20190528090821.GU1658@dhcp22.suse.cz> References: <20190520092801.GA6836@dhcp22.suse.cz> <20190521025533.GH10039@google.com> <20190521062628.GE32329@dhcp22.suse.cz> <20190527075811.GC6879@google.com> <20190527124411.GC1658@dhcp22.suse.cz> <20190528032632.GF6879@google.com> <20190528062947.GL1658@dhcp22.suse.cz> <20190528081351.GA159710@google.com> <20190528084927.GB159710@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190528084927.GB159710@google.com> User-Agent: Mutt/1.10.1 (2018-07-13) 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 Tue 28-05-19 17:49:27, Minchan Kim wrote: > On Tue, May 28, 2019 at 01:31:13AM -0700, Daniel Colascione wrote: > > On Tue, May 28, 2019 at 1:14 AM Minchan Kim wrote: > > > if we went with the per vma fd approach then you would get this > > > > feature automatically because map_files would refer to file backed > > > > mappings while map_anon could refer only to anonymous mappings. > > > > > > The reason to add such filter option is to avoid the parsing overhead > > > so map_anon wouldn't be helpful. > > > > Without chiming on whether the filter option is a good idea, I'd like > > to suggest that providing an efficient binary interfaces for pulling > > memory map information out of processes. Some single-system-call > > method for retrieving a binary snapshot of a process's address space > > complete with attributes (selectable, like statx?) for each VMA would > > reduce complexity and increase performance in a variety of areas, > > e.g., Android memory map debugging commands. > > I agree it's the best we can get *generally*. > Michal, any opinion? I am not really sure this is directly related. I think the primary question that we have to sort out first is whether we want to have the remote madvise call process or vma fd based. This is an important distinction wrt. usability. I have only seen pid vs. pidfd discussions so far unfortunately. An interface to query address range information is a separate but although a related topic. We have /proc//[s]maps for that right now and I understand it is not a general win for all usecases because it tends to be slow for some. I can see how /proc//map_anons could provide per vma information in a binary form via a fd based interface. But I would rather not conflate those two discussions much - well except if it could give one of the approaches more justification but let's focus on the madvise part first. -- Michal Hocko SUSE Labs