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=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 105BCC04AAF for ; Tue, 21 May 2019 06:50:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D48F521773 for ; Tue, 21 May 2019 06:50:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1558421403; bh=EukdVb7ua8yXTr4sHy+0d/eK8g+RFTAGvo7SKqQ24qI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=FmTihcaumvfY8EigQql0r+1Gy4Q/Vb7xesmtSH+1/RNSuz5fsvltFALHyhd2RtKJe R6/M0/jP62GlvV1vnqmm2sfD2/mp++dfNrRNvw3xGwcJIWXk4hNrUMzzDdLugIYqq0 rpRm3F6va92nq1EXLbkNXbE/0GGzgp9BikVZ1CbM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726799AbfEUGuC (ORCPT ); Tue, 21 May 2019 02:50:02 -0400 Received: from mx2.suse.de ([195.135.220.15]:56762 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726193AbfEUGuC (ORCPT ); Tue, 21 May 2019 02:50:02 -0400 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 5C37FAF70; Tue, 21 May 2019 06:50:01 +0000 (UTC) Date: Tue, 21 May 2019 08:50:00 +0200 From: Michal Hocko To: Oleksandr Natalenko Cc: Minchan Kim , Andrew Morton , LKML , linux-mm , Johannes Weiner , Tim Murray , Joel Fernandes , Suren Baghdasaryan , Daniel Colascione , Shakeel Butt , Sonny Rao , Brian Geffon Subject: Re: [RFC 4/7] mm: factor out madvise's core functionality Message-ID: <20190521065000.GH32329@dhcp22.suse.cz> References: <20190520035254.57579-1-minchan@kernel.org> <20190520035254.57579-5-minchan@kernel.org> <20190520142633.x5d27gk454qruc4o@butterfly.localdomain> <20190521012649.GE10039@google.com> <20190521063628.x2npirvs75jxjilx@butterfly.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190521063628.x2npirvs75jxjilx@butterfly.localdomain> 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 21-05-19 08:36:28, Oleksandr Natalenko wrote: [...] > Regarding restricting the hints, I'm definitely interested in having > remote MADV_MERGEABLE/MADV_UNMERGEABLE. But, OTOH, doing it via remote > madvise() introduces another issue with traversing remote VMAs reliably. > IIUC, one can do this via userspace by parsing [s]maps file only, which > is not very consistent, and once some range is parsed, and then it is > immediately gone, a wrong hint will be sent. > > Isn't this a problem we should worry about? See http://lkml.kernel.org/r/20190520091829.GY6836@dhcp22.suse.cz -- Michal Hocko SUSE Labs