From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx123.postini.com [74.125.245.123]) by kanga.kvack.org (Postfix) with SMTP id 26AD26B005D for ; Sun, 6 Jan 2013 02:22:54 -0500 (EST) From: Jason Liu Subject: [PATCH] mm: compaction: fix echo 1 > compact_memory return error issue Date: Sun, 6 Jan 2013 15:44:33 +0800 Message-ID: <1357458273-28558-1-git-send-email-r64343@freescale.com> MIME-Version: 1.0 Content-Type: text/plain Sender: owner-linux-mm@kvack.org List-ID: To: linux-kernel@vger.kernel.org Cc: mgorman@suse.de, akpm@linux-foundation.org, riel@redhat.com, minchan@kernel.org, kamezawa.hiroyu@jp.fujitsu.com, linux-mm@kvack.org 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. Suggested-by:David Rientjes Cc:Mel Gorman Cc:Andrew Morton Cc:Rik van Riel Cc:Minchan Kim Cc:KAMEZAWA Hiroyuki Signed-off-by: Jason Liu --- mm/compaction.c | 6 ++---- 1 files changed, 2 insertions(+), 4 deletions(-) diff --git a/mm/compaction.c b/mm/compaction.c index 6b807e4..f8f5c11 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -1210,7 +1210,7 @@ static int compact_node(int nid) } /* Compact all nodes in the system */ -static int compact_nodes(void) +static void compact_nodes(void) { int nid; @@ -1219,8 +1219,6 @@ 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 */ @@ -1231,7 +1229,7 @@ int sysctl_compaction_handler(struct ctl_table *table, int write, void __user *buffer, size_t *length, loff_t *ppos) { if (write) - return compact_nodes(); + compact_nodes(); return 0; } -- 1.7.5.4 -- 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