Re: Race between cgroup core and the cpuset controller

[Daniel Jordan <daniel.m.jordan-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>]

Hi Tejun,

On 05/23/2017 04:06 PM, Tejun Heo wrote:
> Can you please see whether the following patch fixes the issue?
> Thanks.
>
> diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
> index f6501f4f6040..9e29dba49d6c 100644
> --- a/kernel/cgroup/cpuset.c
> +++ b/kernel/cgroup/cpuset.c
> @@ -176,9 +176,10 @@ typedef enum {
>   } cpuset_flagbits_t;
>   
>   /* convenient tests for these bits */
> -static inline bool is_cpuset_online(const struct cpuset *cs)
> +static inline bool is_cpuset_online(struct cpuset *cs)
>   {
> -	return test_bit(CS_ONLINE, &cs->flags);
> +	return test_bit(CS_ONLINE, &cs->flags) &&
> +		!percpu_ref_is_dying(&cs->css.refcnt);
>   }
>   
>   static inline int is_cpu_exclusive(const struct cpuset *cs)

That does the trick, thanks.

Please let me know if there's anything else I can do to help.

Daniel