| From 7964c06d66c76507d8b6b662bffea770c29ef0ce Mon Sep 17 00:00:00 2001 |
| From: Jason Liu <r64343@freescale.com> |
| Date: Fri, 11 Jan 2013 14:31:47 -0800 |
| Subject: mm: compaction: fix echo 1 > compact_memory return error issue |
| |
| From: Jason Liu <r64343@freescale.com> |
| |
| 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 <r64343@freescale.com> |
| Suggested-by: David Rientjes <rientjes@google.com> |
| Acked-by: Mel Gorman <mgorman@suse.de> |
| Cc: Rik van Riel <riel@redhat.com> |
| Cc: Minchan Kim <minchan@kernel.org> |
| Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> |
| Acked-by: David Rientjes <rientjes@google.com> |
| Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
| Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| mm/compaction.c | 6 ++---- |
| 1 file changed, 2 insertions(+), 4 deletions(-) |
| |
| --- a/mm/compaction.c |
| +++ b/mm/compaction.c |
| @@ -714,14 +714,12 @@ static int compact_node(int nid) |
| } |
| |
| /* Compact all nodes in the system */ |
| -static int compact_nodes(void) |
| +static void compact_nodes(void) |
| { |
| int nid; |
| |
| for_each_online_node(nid) |
| compact_node(nid); |
| - |
| - return COMPACT_COMPLETE; |
| } |
| |
| /* The written value is actually unused, all memory is compacted */ |
| @@ -732,7 +730,7 @@ int sysctl_compaction_handler(struct ctl |
| void __user *buffer, size_t *length, loff_t *ppos) |
| { |
| if (write) |
| - return compact_nodes(); |
| + compact_nodes(); |
| |
| return 0; |
| } |