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=1.2 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FSL_HELO_FAKE,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, T_DKIMWL_WL_HIGH,USER_AGENT_MUTT 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 57066C04AB6 for ; Tue, 28 May 2019 10:33:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 27C3F21726 for ; Tue, 28 May 2019 10:33:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1559039586; bh=SEpCZqrY7Uczo6uQKWN9Jm6Cnozp+DZUsUBrRuMBkZA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=fc3+g8u8LBPurhkzsvpdINrqVhqpiY0LA8bzRxI1hPLsuXQALU6sCT8zRDnDz+vyS osJ33Q5eWALaxoiZ7bEEt80X3h9mL4M7Nsr0liqCKZl/lmONAclXxyN60E0SY41u51 MH2LqdlU2FyXH7FD2ll2FgKRe9UOSfdcn4EnS6+g= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726682AbfE1KdE (ORCPT ); Tue, 28 May 2019 06:33:04 -0400 Received: from mail-pf1-f196.google.com ([209.85.210.196]:32787 "EHLO mail-pf1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726305AbfE1KdE (ORCPT ); Tue, 28 May 2019 06:33:04 -0400 Received: by mail-pf1-f196.google.com with SMTP id z28so11224446pfk.0; Tue, 28 May 2019 03:33:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=krgMSnEVy69yoxUL6+FT3pw/Wcuo2yl9vll0sSUGOww=; b=fvqIxpSuquyR4BpSeT5rFWP7ErwjkwJUnGWEyfvDGxz5/uVzNBZyAiZUKtfnK9WSVm H92bdTd0JQq+meoxC/A7cAvM+LRpEpouDQA/Ac2uSJKJPNOzcy4CzGpjewrZGPEG8LHo QASLekxEG4UQqoj3JFCRy87xxphDAuDtN6Oti3uuco3K8+nygGPwAroVtyo+eM4hURtU 7CKlX+ZoGV4ttxIBpBpa2Bh1pNKOMsk2eIWVef+vUVuyz6yF4SY+KQkJXIyCcdZc0eFm hCLhXnKVp4N6ZqzWkdxWMrxBHfFRe0MCOaSf3xL6YVgnU31InTxQImkkGN5E4ypIlJXY YTGg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to:user-agent; bh=krgMSnEVy69yoxUL6+FT3pw/Wcuo2yl9vll0sSUGOww=; b=j0TkbW6r7Wjap+iM8ApUgWr7NdH3eBffSj8/WSZGSou7MJtsMKNNDKjQx1KKmNSR8F hUBPTCAErCttntXaeIE7fUxzKkKpx0ov0p4MmxsLFxaGYvxezGhjibFcK0SyaXegka8k 3VGFgWg1jZqZsvG4YIHSxPAtVPrrLEHRXCz+pc0NvPvuDaKr66mzJtE43DofzZaxBp3r GvhnnpHNviaW13YOl87xtXHQ/veEKGbm76Vcss3FPIiqBZHZO5qvWmwTMfu+K3VUBm/V qOLygQz8vqIEBKc6jpXu/J9blEXQZgxNTK/PRrJVZ9+53YSOdv02sI1sHUnL7JaMKkrU F1sA== X-Gm-Message-State: APjAAAV0XSewLXRyiMGcwjEAuboD6pa/wZKblJO/RVtuR2VHHi/EdO6I tIEUPPhKcIH6010YIkbod2Y= X-Google-Smtp-Source: APXvYqxc+D0LEa1va91F68TbeYEmhMPMKJQZ9LgkOR5KNw+jdrb9GAAsS0CDZJbmp0XQkrYEFbL5rA== X-Received: by 2002:a62:2c17:: with SMTP id s23mr112033131pfs.51.1559039583555; Tue, 28 May 2019 03:33:03 -0700 (PDT) Received: from google.com ([2401:fa00:d:0:98f1:8b3d:1f37:3e8]) by smtp.gmail.com with ESMTPSA id m7sm8226184pff.44.2019.05.28.03.32.59 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Tue, 28 May 2019 03:33:02 -0700 (PDT) Date: Tue, 28 May 2019 19:32:56 +0900 From: Minchan Kim To: Michal Hocko 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: <20190528103256.GA9199@google.com> References: <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> <20190528090821.GU1658@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190528090821.GU1658@dhcp22.suse.cz> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 28, 2019 at 11:08:21AM +0200, Michal Hocko wrote: > 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. With current usecase, it's per-process API with distinguishable anon/file but thought it could be easily extended later for each address range operation as userspace getting smarter with more information.