Re: [PATCH] memory hotplug: reset pgdat->kswapd to NULL if creatingkernel thread fails

From: Minchan Kim
Date: Tue Aug 21 2012 - 03:37:14 EST


On Tue, Aug 21, 2012 at 02:31:19PM +0800, Wen Congyang wrote:
> If kthread_run() fails, pgdat->kswapd contains errno. When we stop
> this thread, we only check whether pgdat->kswapd is NULL and access
> it. If it contains errno, it will cause page fault. Reset pgdat->kswapd
> to NULL when creating kernel thread fails can avoid this problem.
>
> Signed-off-by: Wen Congyang <wency@xxxxxxxxxxxxxx>
Reviewed-by: Minchan Kim <minchan@xxxxxxxxxx>

Nitpick: Why doesn't online_pages check kswapd_run's return value?
I hope memory-hotplug can handle this error rightly without
relying on this patch in the future.

--
Kind regards,
Minchan Kim
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