From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lf0-f70.google.com (mail-lf0-f70.google.com [209.85.215.70]) by kanga.kvack.org (Postfix) with ESMTP id 5EE646B0069 for ; Fri, 21 Oct 2016 03:31:47 -0400 (EDT) Received: by mail-lf0-f70.google.com with SMTP id f134so21636126lfg.6 for ; Fri, 21 Oct 2016 00:31:47 -0700 (PDT) Received: from mx2.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id r187si2418511wmr.28.2016.10.21.00.31.45 for (version=TLS1 cipher=AES128-SHA bits=128/128); Fri, 21 Oct 2016 00:31:46 -0700 (PDT) Subject: Re: [RFC] fs/proc/meminfo: introduce Unaccounted statistic References: <20161020121149.9935-1-vbabka@suse.cz> <20161020133358.GN14609@dhcp22.suse.cz> From: Vlastimil Babka Message-ID: Date: Fri, 21 Oct 2016 09:31:44 +0200 MIME-Version: 1.0 In-Reply-To: <20161020133358.GN14609@dhcp22.suse.cz> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrew Morton , Mel Gorman , Johannes Weiner , "Kirill A. Shutemov" , Hugh Dickins , David Rientjes On 10/20/2016 03:33 PM, Michal Hocko wrote: > On Thu 20-10-16 14:11:49, Vlastimil Babka wrote: > [...] >> Hi, I'm wondering if people would find this useful. If you think it is, and >> to not make performance worse, I could also make sure in proper submission >> that values are not read via global_page_state() multiple times etc... > > I definitely find this information useful and hate to do the math all > the time but on the other hand this is quite fragile and I can imagine > we can easily forget to add something there and provide a misleading > information to the userspace. So I would be worried with a long term > maintainability of this. I wouldn't fear this that much. Maybe even on the contrary - if we unknowingly change the picture by misacounting something, or changing a counter to become subset of another, and Unaccounted starts to give weird values, it will give us hint that there's either a problem to fix, or a missed documentation update. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org