From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751401AbbCNRO1 (ORCPT ); Sat, 14 Mar 2015 13:14:27 -0400 Received: from mail-wi0-f173.google.com ([209.85.212.173]:38400 "EHLO mail-wi0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751054AbbCNRO0 (ORCPT ); Sat, 14 Mar 2015 13:14:26 -0400 Message-ID: <55046C5B.6020308@gmail.com> Date: Sat, 14 Mar 2015 19:14:03 +0200 From: Alex Dowad User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.4.0 MIME-Version: 1.0 To: David Rientjes , josh@joshtriplett.org CC: linux-kernel@vger.kernel.org, Andrew Morton , Oleg Nesterov , Peter Zijlstra , "Kirill A. Shutemov" , Rik van Riel , Vladimir Davydov Subject: Re: [PATCH 01/32] do_fork(): Rename 'stack_size' argument to reflect actual use References: <1426269888-25600-1-git-send-email-alexinbeijing@gmail.com> <20150313230354.GA11522@cloud> In-Reply-To: Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 14/03/15 01:21, David Rientjes wrote: > On Fri, 13 Mar 2015, josh@joshtriplett.org wrote: > >> On Fri, Mar 13, 2015 at 08:04:16PM +0200, Alex Dowad wrote: >>> The 'stack_size' argument is never used to pass a stack size. It's only used when >>> forking a kernel thread, in which case it is an argument which should be passed >>> to the 'main' function which the kernel thread executes. Hence, rename it to >>> 'kthread_arg'. >> That's not the only use of stack_size. Take a look at the clone2 system >> call (very minimally documented in the clone manpage) and the >> implementation of copy_thread on ia64, which does use stack_size in the >> non-kthread path. >> > Exactly, and it seems like Alex just disregarded this early feedback when > this was first raised that suggested it just be named "arg" and to comment > the individual usage in the functions that get called with the formal. David, just to clarify: your feedback was much appreciated and has not been disregarded. I am still not convinced that "arg" is the best name for the argument now called "stack_start"; I think there must be a better name, but can't think of what it is. If you or others have more suggestions, that would be helpful. Because of the uncertainty, I have avoided modifying that part of the code, and have focused on what seems like a more clear and unequivocal win for readability: renaming the "stack_size" argument. Josh Triplett kindly pointed out that "stack_size" is in fact used for a stack size when processing one particular syscall on one arch. However, rather than naming the args according to that rare case, it seems like a better idea to name them according to the 99.9% case, and add a comment mentioning the 0.1% case. Or maybe "arg1" and "arg2" are really best. If the other maintainers concur with that, I would be happy to rewrite this set of patches accordingly. Again, I appreciate your feedback and hope to receive more (if you have more to give). Thanks, Alex Dowad