From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx113.postini.com [74.125.245.113]) by kanga.kvack.org (Postfix) with SMTP id DFA996B0034 for ; Wed, 14 Aug 2013 23:39:33 -0400 (EDT) Message-ID: <520C4D24.40701@cn.fujitsu.com> Date: Thu, 15 Aug 2013 11:38:12 +0800 From: Tang Chen MIME-Version: 1.0 Subject: Re: [PATCH 1/1] memblock cleanup: Remove unnecessary check in memblock_find_in_range_node() References: <1376536999-4562-1-git-send-email-tangchen@cn.fujitsu.com> <20130815032746.GC4439@htj.dyndns.org> In-Reply-To: <20130815032746.GC4439@htj.dyndns.org> Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=ISO-8859-1; format=flowed Sender: owner-linux-mm@kvack.org List-ID: To: Tejun Heo Cc: mingo@redhat.com, hpa@zytor.com, akpm@linux-foundation.org, liwanp@linux.vnet.ibm.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org On 08/15/2013 11:27 AM, Tejun Heo wrote: > Hello, Tang. > > On Thu, Aug 15, 2013 at 11:23:19AM +0800, Tang Chen wrote: >> Furthermore, we don't need to check "if (this_end< size)" actually. Without >> this confusing check, we only waste some loops. So this patch removes the >> check. >> >> Signed-off-by: Tang Chen >> --- >> mm/memblock.c | 3 --- >> 1 files changed, 0 insertions(+), 3 deletions(-) >> >> diff --git a/mm/memblock.c b/mm/memblock.c >> index a847bfe..e0c626e 100644 >> --- a/mm/memblock.c >> +++ b/mm/memblock.c >> @@ -114,9 +114,6 @@ phys_addr_t __init_memblock memblock_find_in_range_node(phys_addr_t start, >> this_start = clamp(this_start, start, end); >> this_end = clamp(this_end, start, end); >> >> - if (this_end< size) >> - continue; >> - >> cand = round_down(this_end - size, align); >> if (cand>= this_start) >> return cand; > > Hmmm... maybe I'm missing something but are you sure? "this_end - > size" can underflow and "cand>= this_start" will be true incorrectly. > Oh, you are right... Please ignore this. I didn't read it carefully. Thanks. -- 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