From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Thu, 30 Nov 2006 17:31:29 -0800 From: Andrew Morton Subject: Re: [PATCH] Add __GFP_MOVABLE for callers to flag allocations that may be migrated Message-Id: <20061130173129.4ebccaa2.akpm@osdl.org> In-Reply-To: <20061130170746.GA11363@skynet.ie> References: <20061130170746.GA11363@skynet.ie> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Mel Gorman Cc: clameter@sgi.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org List-ID: On Thu, 30 Nov 2006 17:07:46 +0000 mel@skynet.ie (Mel Gorman) wrote: > Am reporting this patch after there were no further comments on the last > version. Am not sure what to do with it - nothing actually uses __GFP_MOVABLE. > It is often known at allocation time when a page may be migrated or not. "often", yes. > This > page adds a flag called __GFP_MOVABLE and GFP_HIGH_MOVABLE. Allocations using > the __GFP_MOVABLE can be either migrated using the page migration mechanism > or reclaimed by syncing with backing storage and discarding. > > Additional credit goes to Christoph Lameter and Linus Torvalds for shaping > the concept. Credit to Hugh Dickens for catching issues with shmem swap > vector and ramfs allocations. > > ... > > @@ -65,7 +65,7 @@ static inline void clear_user_highpage(s > static inline struct page * > alloc_zeroed_user_highpage(struct vm_area_struct *vma, unsigned long vaddr) > { > - struct page *page = alloc_page_vma(GFP_HIGHUSER, vma, vaddr); > + struct page *page = alloc_page_vma(GFP_HIGH_MOVABLE, vma, vaddr); > > if (page) > clear_user_highpage(page, vaddr); But this change is presumptuous. alloc_zeroed_user_highpage() doesn't know that its caller is going to use the page for moveable purposes. (Ditto lots of other places in this patch). -- 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