From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753577AbbCEA6Z (ORCPT ); Wed, 4 Mar 2015 19:58:25 -0500 Received: from mail-pa0-f43.google.com ([209.85.220.43]:42324 "EHLO mail-pa0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751556AbbCEA6Y (ORCPT ); Wed, 4 Mar 2015 19:58:24 -0500 Date: Thu, 5 Mar 2015 09:58:29 +0900 From: Sergey Senozhatsky To: Minchan Kim Cc: Sergey Senozhatsky , Andrew Morton , Nitin Gupta , linux-kernel@vger.kernel.org, Sergey Senozhatsky , Jerome Marchand Subject: Re: [PATCH 0/2] make automatic device_id generation possible Message-ID: <20150305005829.GC14927@swordfish> References: <1425478601-19141-1-git-send-email-sergey.senozhatsky@gmail.com> <20150305001954.GA9563@blaptop> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150305001954.GA9563@blaptop> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, On (03/05/15 09:20), Minchan Kim wrote: > I'm not against but I want to know why we should support > user-defined device id. What usecase do you have in mind? > hm, you never know what people can come up with. that's probably the strongest support argument I can provide. I wish there was something like - my friend Mike has a "device /dev/zram1 is always swap device, device /dev/zram$(id -u) is a per-user zram device (he finds it useful, because just looking at device id he can easily tell who owns that device)" policy. but nothing like that. I just think that it can be useful. no real use cases (well, partly because we don't support device add/remove). /* yet "/dev/zram$(id -u)" thing looks interesting */ user defined id support comes at a price of ~10 lines of code, or even less. we waste much more code to show ->stats, and not all of them are of any real use, to be fair. that just said, that dropping user defined id is not a great deal. ok, let's see if we can come up with anything by the end of this day and I'll send out a removal patch if nothing pop up. -ss > Could we support automatic id support only at this moment? > Then, if some user complains about that in future, we could turn > on user-defined device id easily and we could know the usecase.