From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx117.postini.com [74.125.245.117]) by kanga.kvack.org (Postfix) with SMTP id DC8AD6B0033 for ; Thu, 22 Aug 2013 02:59:12 -0400 (EDT) Date: Thu, 22 Aug 2013 15:59:19 +0900 From: Joonsoo Kim Subject: Re: [PATCH v2 09/20] mm, hugetlb: protect region tracking via newly introduced resv_map lock Message-ID: <20130822065919.GE13415@lge.com> References: <1376040398-11212-1-git-send-email-iamjoonsoo.kim@lge.com> <1376040398-11212-10-git-send-email-iamjoonsoo.kim@lge.com> <87eh9ngxmg.fsf@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87eh9ngxmg.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 On Wed, Aug 21, 2013 at 03:43:27PM +0530, Aneesh Kumar K.V wrote: > > static long region_chg(struct resv_map *resv, long f, long t) > > { > > struct list_head *head = &resv->regions; > > - struct file_region *rg, *nrg; > > + struct file_region *rg, *nrg = NULL; > > long chg = 0; > > > > +retry: > > + spin_lock(&resv->lock); > > /* Locate the region we are before or in. */ > > list_for_each_entry(rg, head, link) > > if (f <= rg->to) > > @@ -202,15 +199,27 @@ static long region_chg(struct resv_map *resv, long f, long t) > > * Subtle, allocate a new region at the position but make it zero > > * size such that we can guarantee to record the reservation. */ > > if (&rg->link == head || t < rg->from) { > > - nrg = kmalloc(sizeof(*nrg), GFP_KERNEL); > > - if (!nrg) > > - return -ENOMEM; > > + if (!nrg) { > > + nrg = kmalloc(sizeof(*nrg), GFP_NOWAIT); > > Do we really need to have the GFP_NOWAIT allocation attempt. Why can't we simply say > allocate and retry ? Or should resv->lock be a mutex ? > Yes, your proposal that simply allocate and retry looks good to me. I will change it. 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