From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Fri, 14 Mar 2008 11:47:06 +0000 From: Mel Gorman Subject: Re: grow_dev_page's __GFP_MOVABLE Message-ID: <20080314114705.GA18381@csn.ul.ie> References: <20080312140831.GD6072@csn.ul.ie> <20080313120755.GC12351@csn.ul.ie> <1205420758.19403.6.camel@dyn9047017100.beaverton.ibm.com> <20080313154428.GD12351@csn.ul.ie> <1205455806.19403.47.camel@dyn9047017100.beaverton.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <1205455806.19403.47.camel@dyn9047017100.beaverton.ibm.com> Sender: owner-linux-mm@kvack.org Return-Path: To: Badari Pulavarty Cc: Hugh Dickins , Andrew Morton , linux-mm List-ID: On (13/03/08 16:50), Badari Pulavarty didst pronounce: > > > > > > page_owner shows: > > > > > > Page allocated via order 0, mask 0x120050 > > > PFN 30625 Block 7 type 2 Flags L > > > > This page is indicated as being on the LRU so it should have been possible > > to reclaim. Is memory hot-remove making any effort to reclaim this page or > > is it depending only on page migration? > > offline_pages() finds all the pages on LRU and tries to migrate them by > calling unmap_and_move(). I don't see any explicit attempt to reclaim. > It tries to migrate the page (move_to_new_page()), but what I have seen > in the past is that these pages have buffer heads attached to them. > So, migrate_page_move_mapping() fails to release the page. (BTW, > I narrowed this in Oct 2007 and forgot most of the details). I can > take a closer look again. Can we reclaim these pages easily ? > They should be, or huge page allocations using lumpy reclaim would also be failing all the time. > > > > > [0xc0000000000c511c] .alloc_pages_current+208 > > > [0xc0000000001049d8] .__find_get_block_slow+88 > > > [0xc0000000004f0bbc] .__wait_on_bit+232 > > > [0xc0000000000994ec] .__page_cache_alloc+24 > > > [0xc000000000104fd8] .__find_get_block+272 > > > [0xc00000000009a124] .find_or_create_page+76 > > > [0xc0000000001063fc] .unlock_buffer+48 > > > [0xc000000000105280] .__getblk+312 > > > > > Thanks, > Badari > -- 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