Re: [patch 1/2] mm, hotplug: fix error handling in mem_online_node()

[KOSAKI Motohiro]

(2011/06/23 10:13), David Rientjes wrote:
> The error handling in mem_online_node() is incorrect: hotadd_new_pgdat() 
> returns NULL if the new pgdat could not have been allocated and a pointer 
> to it otherwise.
> 
> mem_online_node() should fail if hotadd_new_pgdat() fails, not the 
> inverse.  This fixes an issue when memoryless nodes are not onlined and 
> their sysfs interface is not registered when their first cpu is brought 
> up.
> 
> Signed-off-by: David Rientjes <rientjes@xxxxxxxxxx>

Nice catch.

The fault was introduced by commit cf23422b9d76(cpu/mem hotplug: enable CPUs
online before local memory online) iow v2.6.35.

 Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>


> ---
>  mm/memory_hotplug.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
> 
> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
> --- a/mm/memory_hotplug.c
> +++ b/mm/memory_hotplug.c
> @@ -521,7 +521,7 @@ int mem_online_node(int nid)
>  
>  	lock_memory_hotplug();
>  	pgdat = hotadd_new_pgdat(nid, 0);
> -	if (pgdat) {
> +	if (!pgdat) {
>  		ret = -ENOMEM;
>  		goto out;
>  	}
> 
> --
> To unsubscribe, send a message with 'unsubscribe linux-mm' in
> the body to majordomo@xxxxxxxxxx  For more info on Linux MM,
> see: http://www.linux-mm.org/ .
> Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
> Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
> 
> 


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/