From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx132.postini.com [74.125.245.132]) by kanga.kvack.org (Postfix) with SMTP id 0B1456B0034 for ; Thu, 22 Aug 2013 02:50:31 -0400 (EDT) Date: Thu, 22 Aug 2013 15:50:38 +0900 From: Joonsoo Kim Subject: Re: [PATCH v2 03/20] mm, hugetlb: fix subpool accounting handling Message-ID: <20130822065038.GA13415@lge.com> References: <1376040398-11212-1-git-send-email-iamjoonsoo.kim@lge.com> <1376040398-11212-4-git-send-email-iamjoonsoo.kim@lge.com> <87vc2zgzpn.fsf@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87vc2zgzpn.fsf@linux.vnet.ibm.com> Sender: owner-linux-mm@kvack.org List-ID: To: "Aneesh Kumar K.V" Cc: Andrew Morton , Rik van Riel , Mel Gorman , Michal Hocko , KAMEZAWA Hiroyuki , Hugh Dickins , Davidlohr Bueso , David Gibson , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Wanpeng Li , Naoya Horiguchi , Hillf Danton Hello, Aneesh. First of all, thank you for review! On Wed, Aug 21, 2013 at 02:58:20PM +0530, Aneesh Kumar K.V wrote: > Joonsoo Kim writes: > > > If we alloc hugepage with avoid_reserve, we don't dequeue reserved one. > > So, we should check subpool counter when avoid_reserve. > > This patch implement it. > > Can you explain this better ? ie, if we don't have a reservation in the > area chg != 0. So why look at avoid_reserve. We don't consider avoid_reserve when chg != 0. Look at following code. + if (chg || avoid_reserve) + if (hugepage_subpool_get_pages(spool, 1)) It means that if chg != 0, we skip to check avoid_reserve. > > Also the code will become if you did > > if (!chg && avoid_reserve) > chg = 1; > > and then rest of the code will be able to handle the case. We still pass avoid_reserve to dequeue_huge_page_vma() and check avoid_reserve there, so maintaining avoid_reserve and checking it separately is better to understand a logic. And it doesn't matter at all since I eventually unify these in patch 13. 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