From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail138.messagelabs.com (mail138.messagelabs.com [216.82.249.35]) by kanga.kvack.org (Postfix) with ESMTP id 48164900086 for ; Tue, 12 Apr 2011 11:57:29 -0400 (EDT) Received: by bwz17 with SMTP id 17so8275830bwz.14 for ; Tue, 12 Apr 2011 08:57:25 -0700 (PDT) Content-Type: text/plain; charset=utf-8; format=flowed; delsp=yes Subject: Re: [PATCH 3/3] reuse __free_pages_exact() in __alloc_pages_exact() References: <20110411220345.9B95067C@kernel> <20110411220348.D0280E4D@kernel> <1302621864.8321.1856.camel@nimitz> Date: Tue, 12 Apr 2011 17:57:23 +0200 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit From: "Michal Nazarewicz" Message-ID: In-Reply-To: <1302621864.8321.1856.camel@nimitz> Sender: owner-linux-mm@kvack.org List-ID: To: Dave Hansen Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Timur Tabi , Andi Kleen , Mel Gorman , Andrew Morton , David Rientjes On Tue, 12 Apr 2011 17:24:24 +0200, Dave Hansen wrote: > On Tue, 2011-04-12 at 12:29 +0200, Michal Nazarewicz wrote: >> On Tue, 12 Apr 2011 00:03:48 +0200, Dave Hansen >> >> wrote: >> > diff -puN mm/page_alloc.c~reuse-free-exact mm/page_alloc.c >> > --- linux-2.6.git/mm/page_alloc.c~reuse-free-exact 2011-04-11 >> > 15:01:17.701822598 -0700 >> > +++ linux-2.6.git-dave/mm/page_alloc.c 2011-04-11 15:01:17.713822594 >> > -0700 >> > @@ -2338,14 +2338,11 @@ struct page *__alloc_pages_exact(gfp_t g >> > page = alloc_pages(gfp_mask, order); >> > if (page) { >> > - struct page *alloc_end = page + (1 << order); >> > - struct page *used = page + nr_pages; >> > + struct page *unused_start = page + nr_pages; >> > + int nr_unused = (1 << order) - nr_pages; >> >> How about unsigned long? > > Personally, I'd rather leave this up to the poor sucker that tries to > set MAX_ORDER to 33. If someone did that, we'd end up with kernels that > couldn't even boot on systems with less than 16GB of RAM since the > (required) flatmem mem_map[] would take up ~14.3GB. They couldn't > handle memory holes and couldn't be NUMA-aware, either. I was thinking more about the fact that the int will get converted anyway when calling __free_pages_exact() and it makes no sense for number of pages to be negative. Just a suggestion, no strong feelings. -- Best regards, _ _ .o. | Liege of Serenely Enlightened Majesty of o' \,=./ `o ..o | Computer Science, Michal "mina86" Nazarewicz (o o) ooo +----------ooO--(_)--Ooo-- -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org