From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Thu, 13 Apr 2006 17:36:53 -0700 (PDT) From: Christoph Lameter Subject: Re: [PATCH 2/5] Swapless V2: Add migration swap entries In-Reply-To: <20060413171331.1752e21f.akpm@osdl.org> Message-ID: References: <20060413235406.15398.42233.sendpatchset@schroedinger.engr.sgi.com> <20060413235416.15398.49978.sendpatchset@schroedinger.engr.sgi.com> <20060413171331.1752e21f.akpm@osdl.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Andrew Morton Cc: hugh@veritas.com, linux-kernel@vger.kernel.org, lee.schermerhorn@hp.com, linux-mm@kvack.org, taka@valinux.co.jp, marcelo.tosatti@cyclades.com, kamezawa.hiroyu@jp.fujitsu.com List-ID: 1. Add explanation for the yield 2. Move unlikely to is_migration_entry (Does that really work??) Signed-off-by: Christoph Lameter Index: linux-2.6.17-rc1-mm2/mm/memory.c =================================================================== --- linux-2.6.17-rc1-mm2.orig/mm/memory.c 2006-04-13 16:43:10.000000000 -0700 +++ linux-2.6.17-rc1-mm2/mm/memory.c 2006-04-13 17:32:36.000000000 -0700 @@ -1880,7 +1880,11 @@ static int do_swap_page(struct mm_struct entry = pte_to_swp_entry(orig_pte); - if (unlikely(is_migration_entry(entry))) { + if (is_migration_entry(entry)) { + /* + * We cannot access the page because of ongoing page + * migration. See if we can do something else. + */ yield(); goto out; } Index: linux-2.6.17-rc1-mm2/include/linux/swapops.h =================================================================== --- linux-2.6.17-rc1-mm2.orig/include/linux/swapops.h 2006-04-13 16:43:10.000000000 -0700 +++ linux-2.6.17-rc1-mm2/include/linux/swapops.h 2006-04-13 17:32:58.000000000 -0700 @@ -77,7 +77,7 @@ static inline swp_entry_t make_migration static inline int is_migration_entry(swp_entry_t entry) { - return swp_type(entry) == SWP_TYPE_MIGRATION; + return unlikely(swp_type(entry) == SWP_TYPE_MIGRATION); } static inline struct page *migration_entry_to_page(swp_entry_t entry) -- 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