From mboxrd@z Thu Jan 1 00:00:00 1970 From: clameter@sgi.com Subject: [27/37] compound pages: Allow use of get_page_unless_zero with compound pages Date: Wed, 20 Jun 2007 11:29:34 -0700 Message-ID: <20070620183012.273119366@sgi.com> References: <20070620182907.506775016@sgi.com> Cc: Christoph Hellwig , Mel Gorman To: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Return-path: Received: from netops-testserver-4-out.sgi.com ([192.48.171.29]:46753 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1757773AbXFTSaN (ORCPT ); Wed, 20 Jun 2007 14:30:13 -0400 Cc: William Lee Irwin III , David Chinner Cc: Jens Axboe , Badari Pulavarty Cc: Maxim Levitsky Content-Disposition: inline; filename=compound_get_one_unless Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org This will be needed by targeted slab reclaim in order to ensure that a compound page allocated by SLUB will not go away under us. It also may be needed if Mel starts to implement defragmentation. The moving of compound pages may require the establishment of a reference before the use of page migration functions. Signed-off-by: Christoph Lameter --- include/linux/mm.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) Index: vps/include/linux/mm.h =================================================================== --- vps.orig/include/linux/mm.h 2007-06-12 19:06:28.000000000 -0700 +++ vps/include/linux/mm.h 2007-06-12 19:06:41.000000000 -0700 @@ -292,7 +292,7 @@ static inline int put_page_testzero(stru */ static inline int get_page_unless_zero(struct page *page) { - VM_BUG_ON(PageCompound(page)); + VM_BUG_ON(PageTail(page)); return atomic_inc_not_zero(&page->_count); } --