Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964862AbVKQVBP (ORCPT ); Thu, 17 Nov 2005 16:01:15 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964863AbVKQVBP (ORCPT ); Thu, 17 Nov 2005 16:01:15 -0500 Received: from holomorphy.com ([66.93.40.71]:18621 "EHLO holomorphy.com") by vger.kernel.org with ESMTP id S964862AbVKQVBO (ORCPT ); Thu, 17 Nov 2005 16:01:14 -0500 Date: Thu, 17 Nov 2005 12:59:28 -0800 From: William Lee Irwin III To: Hugh Dickins Cc: Andrew Morton , Nick Piggin , Paul Mackerras , Ben Herrenschmidt , "David S. Miller" , linux-kernel@vger.kernel.org Subject: Re: [PATCH 05/11] unpaged: VM_UNPAGED Message-ID: <20051117205928.GL6916@holomorphy.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Organization: The Domain of Holomorphy User-Agent: Mutt/1.5.9i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1496 Lines: 28 On Thu, Nov 17, 2005 at 07:34:55PM +0000, Hugh Dickins wrote: > Although we tend to associate VM_RESERVED with remap_pfn_range, quite a > few drivers set VM_RESERVED on areas which are then populated by nopage. > The PageReserved removal in 2.6.15-rc1 changed VM_RESERVED not to free > pages in zap_pte_range, without changing those drivers not to set it: > so their pages just leak away. > Let's not change miscellaneous drivers now: introduce VM_UNPAGED at the > core, to flag the special areas where the ptes may have no struct page, > or if they have then it's not to be touched. Replace most instances of > VM_RESERVED in core mm by VM_UNPAGED. Force it on in remap_pfn_range, > and the sparc and sparc64 io_remap_pfn_range. > Revert addition of VM_RESERVED to powerpc vdso, it's not needed there. > Is it needed anywhere? It still governs the mm->reserved_vm statistic, > and special vmas not to be merged, and areas not to be core dumped; but > could probably be eliminated later (the drivers are probably specifying > it because in 2.4 it kept swapout off the vma, but in 2.6 we work from > the LRU, which these pages don't get on). Eminently reasonable. This solves a lot of problems. Acked-by: William Irwin -- wli - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/