Re: [PATCH] net: decrement memcg jump label when limit, not usage, is changed

[David Miller <davem@davemloft.net>]

From: Glauber Costa <glommer@parallels.com>
Date: Thu, 12 Jan 2012 16:16:06 +0400

> The logic of the current code is that whenever we destroy
> a cgroup that had its limit set (set meaning different than
> maximum), we should decrement the jump_label counter.
> Otherwise we assume it was never incremented.
> 
> But what the code actually does is test for RES_USAGE
> instead of RES_LIMIT. Usage being different than maximum
> is likely to be true most of the time.
> 
> The effect of this is that the key must become negative,
> and since the jump_label test says:
> 
>         !!atomic_read(&key->enabled);
> 
> we'll have jump_labels still on when no one else is
> using this functionality.
> 
> Signed-off-by: Glauber Costa <glommer@parallels.com>
> CC: David S. Miller <davem@davemloft.net>

Applied, thanks.