From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail191.messagelabs.com (mail191.messagelabs.com [216.82.242.19]) by kanga.kvack.org (Postfix) with SMTP id D86536B020A for ; Thu, 29 Apr 2010 04:32:25 -0400 (EDT) Received: by pwi10 with SMTP id 10so4902258pwi.14 for ; Thu, 29 Apr 2010 01:32:24 -0700 (PDT) Subject: Re: [RFC PATCH -v3] take all anon_vma locks in anon_vma_lock From: Minchan Kim In-Reply-To: <20100429081521.GM15815@csn.ul.ie> References: <1272403852-10479-3-git-send-email-mel@csn.ul.ie> <20100427231007.GA510@random.random> <20100428091555.GB15815@csn.ul.ie> <20100428153525.GR510@random.random> <20100428155558.GI15815@csn.ul.ie> <20100428162305.GX510@random.random> <20100428134719.32e8011b@annuminas.surriel.com> <20100428142510.09984e15@annuminas.surriel.com> <20100428161711.5a815fa8@annuminas.surriel.com> <20100428165734.6541bab3@annuminas.surriel.com> <20100429081521.GM15815@csn.ul.ie> Content-Type: text/plain; charset="UTF-8" Date: Thu, 29 Apr 2010 17:32:17 +0900 Message-ID: <1272529937.2100.219.camel@barrios-desktop> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: Mel Gorman Cc: Rik van Riel , Andrea Arcangeli , Linux-MM , LKML , KAMEZAWA Hiroyuki , Christoph Lameter , Andrew Morton List-ID: On Thu, 2010-04-29 at 09:15 +0100, Mel Gorman wrote: > On Wed, Apr 28, 2010 at 04:57:34PM -0400, Rik van Riel wrote: > > Take all the locks for all the anon_vmas in anon_vma_lock, this properly > > excludes migration and the transparent hugepage code from VMA changes done > > by mmap/munmap/mprotect/expand_stack/etc... > > > > In vma_adjust(), what prevents something like rmap_map seeing partial > updates while the following lines execute? > > vma->vm_start = start; > vma->vm_end = end; > vma->vm_pgoff = pgoff; > if (adjust_next) { > next->vm_start += adjust_next << PAGE_SHIFT; > next->vm_pgoff += adjust_next; > } > They would appear to happen outside the lock, even with this patch. The > update happened within the lock in 2.6.33. > > > This part does it. :) ---- @@ -578,6 +578,7 @@ again: remove_next = 1 + (end > next->vm_end); } } + anon_vma_lock(vma, &mm->mmap_sem); if (root) { flush_dcache_mmap_lock(mapping); vma_prio_tree_remove(vma, root); @@ -599,6 +600,7 @@ again: remove_next = 1 + (end > next->vm_end); vma_prio_tree_insert(vma, root); flush_dcache_mmap_unlock(mapping); } + anon_vma_unlock(vma); --- But we still need patch about shift_arg_pages. -- Kind regards, Minchan Kim -- 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