I will try that patch tomorrow. My only concern about that is the use of
WARN_ON().
As I may have mentioned in my note of 6/27, I saw about 600 instances of the
warning
message just during boot of the PowerPC kernel. I doubt that we want to see
that on
an ongoing basis.
Michael
On 06/13/2017 03:10 PM, Tejun Heo wrote:
> Hello,
>
> On Tue, Jun 13, 2017 at 03:04:30PM -0500, Michael Bringmann wrote:
>> @@ -3564,19 +3564,28 @@ static struct pool_workqueue
>> *alloc_unbound_pwq(struct workqueue_struct *wq,
>> static bool wq_calc_node_cpumask(const struct workqueue_attrs *attrs, int
>> node,
>> int cpu_going_down, cpumask_t *cpumask)
>> {
>> + cpumask_t onl_targ_cm;
>> +
>> if (!wq_numa_enabled || attrs->no_numa)
>> goto use_dfl;
>>
>> /* does @node have any online CPUs @attrs wants? */
>> - cpumask_and(cpumask, cpumask_of_node(node), attrs->cpumask);
>> + cpumask_and(&onl_targ_cm, cpumask_of_node(node), attrs->cpumask);
>> if (cpu_going_down >= 0)
>> - cpumask_clear_cpu(cpu_going_down, cpumask);
>> + cpumask_clear_cpu(cpu_going_down, &onl_targ_cm);
>>
>> - if (cpumask_empty(cpumask))
>> + if (cpumask_empty(&onl_targ_cm))
>> goto use_dfl;
>>
>> /* yeap, return possible CPUs in @node that @attrs wants */
>> cpumask_and(cpumask, attrs->cpumask, wq_numa_possible_cpumask[node]);
>> +
>> + if (cpumask_weight(&onl_targ_cm) > cpumask_weight(cpumask)) {
>> + printk(KERN_INFO "WARNING: WQ cpumask: onl intersect > "
>> + "possible intersect\n");
>> + return false;
>> + }
>
> Yeah, alternatively, we can just add right before returning,
>
> if (WARN_ON(cpumask_empty(cpumask)))
> return false;
>
> Thanks.
>
--
Michael W. Bringmann
Linux Technology Center
IBM Corporation
Tie-Line 363-5196
External: (512) 286-5196
Cell: (512) 466-0650
m...@linux.vnet.ibm.com
