Re: [patch -mm] memcg: make oom killer a no-op when no killable task can be found

[Balbir Singh <balbir@linux.vnet.ibm.com>]

* David Rientjes <rientjes@google.com> [2010-03-31 00:08:38]:

> It's pointless to try to kill current if select_bad_process() did not
> find an eligible task to kill in mem_cgroup_out_of_memory() since it's
> guaranteed that current is a member of the memcg that is oom and it is,
> by definition, unkillable.
> 
> Signed-off-by: David Rientjes <rientjes@google.com>
> ---
>  mm/oom_kill.c |    5 +----
>  1 files changed, 1 insertions(+), 4 deletions(-)
> 
> diff --git a/mm/oom_kill.c b/mm/oom_kill.c
> --- a/mm/oom_kill.c
> +++ b/mm/oom_kill.c
> @@ -500,12 +500,9 @@ void mem_cgroup_out_of_memory(struct mem_cgroup *mem, gfp_t gfp_mask)
>  	read_lock(&tasklist_lock);
>  retry:
>  	p = select_bad_process(&points, limit, mem, CONSTRAINT_NONE, NULL);
> -	if (PTR_ERR(p) == -1UL)
> +	if (!p || PTR_ERR(p) == -1UL)
>  		goto out;

Should we have a bit fat WAR_ON_ONCE() here?

-- 
	Three Cheers,
	Balbir

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