From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754039Ab2FMQhS (ORCPT ); Wed, 13 Jun 2012 12:37:18 -0400 Received: from e28smtp09.in.ibm.com ([122.248.162.9]:42165 "EHLO e28smtp09.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752624Ab2FMQhQ (ORCPT ); Wed, 13 Jun 2012 12:37:16 -0400 From: "Aneesh Kumar K.V" To: Michal Hocko Cc: linux-mm@kvack.org, kamezawa.hiroyu@jp.fujitsu.com, dhillf@gmail.com, rientjes@google.com, akpm@linux-foundation.org, hannes@cmpxchg.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org Subject: Re: [PATCH -V9 04/15] hugetlb: use mmu_gather instead of a temporary linked list for accumulating pages In-Reply-To: <20120613145923.GA14777@tiehlicka.suse.cz> References: <1339583254-895-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <1339583254-895-5-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <20120613145923.GA14777@tiehlicka.suse.cz> User-Agent: Notmuch/0.13.2+35~g0ff57e7 (http://notmuchmail.org) Emacs/24.1.50.1 (x86_64-unknown-linux-gnu) Date: Wed, 13 Jun 2012 22:07:06 +0530 Message-ID: <871uljnp71.fsf@skywalker.in.ibm.com> MIME-Version: 1.0 Content-Type: text/plain x-cbid: 12061316-2674-0000-0000-000004E365B8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Michal Hocko writes: > On Wed 13-06-12 15:57:23, Aneesh Kumar K.V wrote: >> From: "Aneesh Kumar K.V" >> >> Use a mmu_gather instead of a temporary linked list for accumulating >> pages when we unmap a hugepage range > > Sorry for coming up with the comment that late but you owe us an > explanation _why_ you are doing this. > > I assume that this fixes a real problem when we take i_mmap_mutex > already up in > unmap_mapping_range > mutex_lock(&mapping->i_mmap_mutex); > unmap_mapping_range_tree | unmap_mapping_range_list > unmap_mapping_range_vma > zap_page_range_single > unmap_single_vma > unmap_hugepage_range > mutex_lock(&vma->vm_file->f_mapping->i_mmap_mutex); > > And that this should have been marked for stable as well (I haven't > checked when this has been introduced). Switch to mmu_gather is to get rid of the use of page->lru so that i can use it for active list. -aneesh