From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail172.messagelabs.com (mail172.messagelabs.com [216.82.254.3]) by kanga.kvack.org (Postfix) with SMTP id 4A7A68D0006 for ; Sun, 24 Oct 2010 22:45:47 -0400 (EDT) Received: from m3.gw.fujitsu.co.jp ([10.0.50.73]) by fgwmail6.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id o9P2jiGt012413 for (envelope-from kamezawa.hiroyu@jp.fujitsu.com); Mon, 25 Oct 2010 11:45:44 +0900 Received: from smail (m3 [127.0.0.1]) by outgoing.m3.gw.fujitsu.co.jp (Postfix) with ESMTP id 26C6345DE50 for ; Mon, 25 Oct 2010 11:45:44 +0900 (JST) Received: from s3.gw.fujitsu.co.jp (s3.gw.fujitsu.co.jp [10.0.50.93]) by m3.gw.fujitsu.co.jp (Postfix) with ESMTP id 04A7445DE4D for ; Mon, 25 Oct 2010 11:45:44 +0900 (JST) Received: from s3.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s3.gw.fujitsu.co.jp (Postfix) with ESMTP id E5063E18001 for ; Mon, 25 Oct 2010 11:45:43 +0900 (JST) Received: from m106.s.css.fujitsu.com (m106.s.css.fujitsu.com [10.249.87.106]) by s3.gw.fujitsu.co.jp (Postfix) with ESMTP id 9F117E08003 for ; Mon, 25 Oct 2010 11:45:43 +0900 (JST) Date: Mon, 25 Oct 2010 11:40:17 +0900 From: KAMEZAWA Hiroyuki Subject: Re: [PATCH] do_migrate_range: avoid failure as much as possible Message-Id: <20101025114017.86ee5e54.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <1287974851-4064-1-git-send-email-lliubbo@gmail.com> References: <1287974851-4064-1-git-send-email-lliubbo@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: Bob Liu Cc: akpm@linux-foundation.org, linux-mm@kvack.org, fengguang.wu@intel.com, mel@csn.ul.ie, kosaki.motohiro@jp.fujitsu.com List-ID: On Mon, 25 Oct 2010 10:47:31 +0800 Bob Liu wrote: > It's normal for isolate_lru_page() to fail at times. The failures are > typically temporal and may well go away when offline_pages() retries > the call. So it seems more reasonable to migrate as much as possible > to increase the chance of complete success in next retry. > > This patch remove page_count() check and remove putback_lru_pages() and > call migrate_pages() regardless of not_managed to reduce failure as much > as possible. > > Signed-off-by: Bob Liu -EBUSY should be returned. -Kame > --- > mm/memory_hotplug.c | 12 ------------ > 1 files changed, 0 insertions(+), 12 deletions(-) > > diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c > index a4cfcdc..b64cc9b 100644 > --- a/mm/memory_hotplug.c > +++ b/mm/memory_hotplug.c > @@ -687,7 +687,6 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn) > unsigned long pfn; > struct page *page; > int move_pages = NR_OFFLINE_AT_ONCE_PAGES; > - int not_managed = 0; > int ret = 0; > LIST_HEAD(source); > > @@ -709,10 +708,6 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn) > page_is_file_cache(page)); > > } else { > - /* Becasue we don't have big zone->lock. we should > - check this again here. */ > - if (page_count(page)) > - not_managed++; > #ifdef CONFIG_DEBUG_VM > printk(KERN_ALERT "removing pfn %lx from LRU failed\n", > pfn); > @@ -720,13 +715,6 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn) > #endif > } > } > - ret = -EBUSY; > - if (not_managed) { > - if (!list_empty(&source)) > - putback_lru_pages(&source); > - goto out; > - } > - ret = 0; > if (list_empty(&source)) > goto out; > /* this function returns # of failed pages */ > -- > 1.6.3.3 > > -- 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