From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail143.messagelabs.com (mail143.messagelabs.com [216.82.254.35]) by kanga.kvack.org (Postfix) with SMTP id 79D046B004D for ; Sun, 24 May 2009 09:43:52 -0400 (EDT) Date: Sun, 24 May 2009 22:44:28 +0900 (JST) From: KOSAKI Motohiro Subject: Re: [PATCH] Warn if we run out of swap space In-Reply-To: References: Message-Id: <20090524144056.0849.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: Christoph Lameter Cc: kosaki.motohiro@jp.fujitsu.com, akpm@linux-foundation.org, linux-mm@kvack.org, Pavel Machek , Dave Hansen List-ID: Hi I have two question. > Subject: Warn if we run out of swap space > > Running out of swap space means that the evicton of anonymous pages may no longer > be possible which can lead to OOM conditions. > > Print a warning when swap space first becomes exhausted. > > Signed-off-by: Christoph Lameter > > --- > mm/swapfile.c | 5 +++++ > 1 file changed, 5 insertions(+) > > Index: linux-2.6/mm/swapfile.c > =================================================================== > --- linux-2.6.orig/mm/swapfile.c 2009-05-22 12:25:19.000000000 -0500 > +++ linux-2.6/mm/swapfile.c 2009-05-22 13:56:10.000000000 -0500 > @@ -380,6 +380,7 @@ swp_entry_t get_swap_page(void) > pgoff_t offset; > int type, next; > int wrapped = 0; > + static int printed = 0; > > spin_lock(&swap_lock); > if (nr_swap_pages <= 0) > @@ -410,6 +411,10 @@ swp_entry_t get_swap_page(void) > } > > nr_swap_pages++; > + if (!printed) { > + printed = 1; > + printk(KERN_WARNING "All of swap is in use. Some pages cannot be swapped out."); > + } Why don't you use WARN_ONCE()? lumpy reclaim on no swap system makes this warnings, right? if so, I think it's a bit annoy. > noswap: > spin_unlock(&swap_lock); > return (swp_entry_t) {0}; -- 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