Re: [PATCH] mm: compaction: fix echo 1 > compact_memory return error issue

[Mel Gorman <mgorman@suse.de>]

On Sun, Jan 06, 2013 at 03:44:33PM +0800, Jason Liu wrote:
> 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 <rientjes@google.com>
> Cc:Mel Gorman <mgorman@suse.de>
> Cc:Andrew Morton <akpm@linux-foundation.org>
> Cc:Rik van Riel <riel@redhat.com>
> Cc:Minchan Kim <minchan@kernel.org>
> Cc:KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
> Signed-off-by: Jason Liu <r64343@freescale.com>

Acked-by: Mel Gorman <mgorman@suse.de>

-- 
Mel Gorman
SUSE Labs