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Date: Thu, 10 Mar 2011 01:22:33 +0200
From: Alexey Dobriyan <adobriyan@gmail.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org
Subject: Re: [PATCH] proc: make struct proc_dir_entry::namelen unsigned int
Message-ID: <20110309232233.GA24596@p183.telecom.by>
References: <20110308105428.GA5767@p183.telecom.by>
 <20110309150306.90369913.akpm@linux-foundation.org>
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On Wed, Mar 09, 2011 at 03:03:06PM -0800, Andrew Morton wrote:
> On Tue, 8 Mar 2011 12:54:28 +0200
> Alexey Dobriyan <adobriyan@gmail.com> wrote:
> 
> > Space is not really conserved, because of natural alignment for the next field.
> > sizeof(struct proc_dir_entry) remains the same.
> > 
> 
> What is the reason for this patch??

1. namelen is declared "unsigned short" which hints for "maybe space savings".
   Indeed in 2.4 struct proc_dir_entry looked like:

	struct proc_dir_entry {
		unsigned short low_ino;
		unsigned short namelen;

   Now, low_ino is "unsigned int", all savings were gone for a long time.
   "struct proc_dir_entry" is not that countless to worry about it's size,
   anyway.

2. converting from unsigned short to int/unsigned int can only create
   problems, we better play it safe.