From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail144.messagelabs.com (mail144.messagelabs.com [216.82.254.51]) by kanga.kvack.org (Postfix) with ESMTP id BBBA26B01B4 for ; Fri, 28 May 2010 10:48:45 -0400 (EDT) Date: Fri, 28 May 2010 15:48:24 +0100 From: Mel Gorman Subject: Re: [PATCH 2/8] hugetlb, rmap: add reverse mapping for hugepage Message-ID: <20100528144824.GD9774@csn.ul.ie> References: <1275006562-18946-1-git-send-email-n-horiguchi@ah.jp.nec.com> <1275006562-18946-3-git-send-email-n-horiguchi@ah.jp.nec.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <1275006562-18946-3-git-send-email-n-horiguchi@ah.jp.nec.com> Sender: owner-linux-mm@kvack.org To: Naoya Horiguchi Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andi Kleen , Andrew Morton , Wu Fengguang , Andrea Arcangeli , Larry Woodman , Lee Schermerhorn List-ID: On Fri, May 28, 2010 at 09:29:16AM +0900, Naoya Horiguchi wrote: > This patch adds reverse mapping feature for hugepage by introducing > mapcount for shared/private-mapped hugepage and anon_vma for > private-mapped hugepage. > > While hugepage is not currently swappable, reverse mapping can be useful > for memory error handler. > > Without this patch, memory error handler cannot identify processes > using the bad hugepage nor unmap it from them. That is: > - for shared hugepage: > we can collect processes using a hugepage through pagecache, > but can not unmap the hugepage because of the lack of mapcount. > - for privately mapped hugepage: > we can neither collect processes nor unmap the hugepage. > This patch solves these problems. > > This patch include the bug fix given by commit 23be7468e8, so reverts it. > > Dependency: > "hugetlb: move definition of is_vm_hugetlb_page() to hugepage_inline.h" > > ChangeLog since May 24. > - create hugetlb_inline.h and move is_vm_hugetlb_index() in it. > - move functions setting up anon_vma for hugepage into mm/rmap.c. > > ChangeLog since May 13. > - rebased to 2.6.34 > - fix logic error (in case that private mapping and shared mapping coexist) > - move is_vm_hugetlb_page() into include/linux/mm.h to use this function > from linear_page_index() > - define and use linear_hugepage_index() instead of compound_order() > - use page_move_anon_rmap() in hugetlb_cow() > - copy exclusive switch of __set_page_anon_rmap() into hugepage counterpart. > - revert commit 24be7468 completely > > Signed-off-by: Naoya Horiguchi > Cc: Andi Kleen > Cc: Andrew Morton > Cc: Wu Fengguang > Cc: Mel Gorman > Cc: Andrea Arcangeli > Cc: Larry Woodman > Cc: Lee Schermerhorn Ok, I could find no other problems with the hugetlb side of things in the first two patches. I haven't looked at the hwpoison parts but I'm assuming Andi has looked at those already. Thanks Acked-by: Mel Gorman -- Mel Gorman Part-time Phd Student Linux Technology Center University of Limerick IBM Dublin Software Lab -- 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