From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx200.postini.com [74.125.245.200]) by kanga.kvack.org (Postfix) with SMTP id AF2086B0081 for ; Wed, 17 Apr 2013 05:56:16 -0400 (EDT) In-Reply-To: <516D90F6.3020603@linux.intel.com> Subject: Re: Re: [PATCH] futex: bugfix for futex-key conflict when futex use hugepage MIME-Version: 1.0 Message-ID: From: zhang.yi20@zte.com.cn Date: Wed, 17 Apr 2013 17:55:29 +0800 Content-Type: text/plain; charset="US-ASCII" Sender: owner-linux-mm@kvack.org List-ID: To: Darren Hart Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Ingo Molnar , Peter Zijlstra , Thomas Gleixner Darren Hart wrote on 2013/04/17 01:57:10: > Again, a functional testcase in futextest would be a good idea. This > helps validate the patch and also can be used to identify regressions in > the future. I will post the testcase code later. > > What is the max value of comp_idx? Are we at risk of truncating it? > Looks like not really from my initial look. > > This also needs a comment in futex.h describing the usage of the offset > field in union futex_key as well as above get_futex_key describing the > key for shared mappings. > > As far as I know , the max size of one hugepage is 1 GBytes for x86 cpu. Can some other cpus support greater hugepage even more than 4 GBytes? If so, we can change the type of 'offset' from int to long to avoid truncating. -- 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