From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757331Ab3AOWpf (ORCPT ); Tue, 15 Jan 2013 17:45:35 -0500 Received: from mail.kernel.org ([198.145.19.201]:44935 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756193Ab3AOWpa (ORCPT ); Tue, 15 Jan 2013 17:45:30 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg Kroah-Hartman , alan@lxorguk.ukuu.org.uk, Jason Liu , David Rientjes , Mel Gorman , Rik van Riel , Minchan Kim , KAMEZAWA Hiroyuki , Andrew Morton , Linus Torvalds Subject: [ 010/171] mm: compaction: fix echo 1 > compact_memory return error issue Date: Tue, 15 Jan 2013 14:42:55 -0800 Message-Id: <20130115224314.154461212@linuxfoundation.org> X-Mailer: git-send-email 1.8.1.336.g94702dd In-Reply-To: <20130115224313.394976595@linuxfoundation.org> References: <20130115224313.394976595@linuxfoundation.org> User-Agent: quilt/0.60-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jason Liu commit 7964c06d66c76507d8b6b662bffea770c29ef0ce upstream. when run the folloing command under shell, it will return error sh/$ echo 1 > /proc/sys/vm/compact_memory sh/$ sh: write error: Bad address After strace, I found the following log: ... write(1, "1\n", 2) = 3 write(1, "", 4294967295) = -1 EFAULT (Bad address) write(2, "echo: write error: Bad address\n", 31echo: write error: Bad address ) = 31 This tells system return 3(COMPACT_COMPLETE) after write data to compact_memory. The fix is to make the system just return 0 instead 3(COMPACT_COMPLETE) from sysctl_compaction_handler after compaction_nodes finished. Signed-off-by: Jason Liu Suggested-by: David Rientjes Acked-by: Mel Gorman Cc: Rik van Riel Cc: Minchan Kim Cc: KAMEZAWA Hiroyuki Acked-by: David Rientjes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/compaction.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) --- a/mm/compaction.c +++ b/mm/compaction.c @@ -736,7 +736,7 @@ static int compact_node(int nid) } /* Compact all nodes in the system */ -static int compact_nodes(void) +static void compact_nodes(void) { int nid; @@ -745,8 +745,6 @@ static int compact_nodes(void) for_each_online_node(nid) compact_node(nid); - - return COMPACT_COMPLETE; } /* The written value is actually unused, all memory is compacted */ @@ -757,7 +755,7 @@ int sysctl_compaction_handler(struct ctl void __user *buffer, size_t *length, loff_t *ppos) { if (write) - return compact_nodes(); + compact_nodes(); return 0; }