Re: [PATCH 3/4] workqueue: Update workqueue's possible cpumask when a new node, coming up.

[Kamezawa Hiroyuki]

(2014/12/16 17:10), Kamezawa Hiroyuki wrote:
> (2014/12/16 16:49), Lai Jiangshan wrote:
> > On 12/15/2014 07:18 PM, Kamezawa Hiroyuki wrote:
> > > Workqueue keeps cpu<->node relationship including all possible cpus.
> > > The original information was made at boot but it may change when
> > > a new node is added.
> > >
> > > Update information if a new node is ready with using node-hotplug callback.
> > >
> > > Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
> > > ---
> > >   include/linux/memory_hotplug.h |  2 ++
> > >   kernel/workqueue.c             | 28 +++++++++++++++++++++++++++-
> > >   mm/memory_hotplug.c            |  4 ++++
> > >   3 files changed, 33 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h
> > > index 8f1a419..cd3cb67 100644
> > > --- a/include/linux/memory_hotplug.h
> > > +++ b/include/linux/memory_hotplug.h
> > > @@ -270,4 +270,6 @@ extern void sparse_remove_one_section(struct zone *zone, struct mem_section *ms)
> > >   extern struct page *sparse_decode_mem_map(unsigned long coded_mem_map,
> > >                         unsigned long pnum);
> > >
> > > +/* update for workqueues */
> > > +void workqueue_node_register(int node);
> > >   #endif /* __LINUX_MEMORY_HOTPLUG_H */
> > > diff --git a/kernel/workqueue.c b/kernel/workqueue.c
> > > index 2fd0bd7..5499b76 100644
> > > --- a/kernel/workqueue.c
> > > +++ b/kernel/workqueue.c
> > > @@ -266,7 +266,7 @@ struct workqueue_struct {
> > >   static struct kmem_cache *pwq_cache;
> > >
> > >   static cpumask_var_t *wq_numa_possible_cpumask;
> > > -                    /* possible CPUs of each node */
> > > +                    /* PL: possible CPUs of each node */
> > >
> > >   static bool wq_disable_numa;
> > >   module_param_named(disable_numa, wq_disable_numa, bool, 0444);
> > > @@ -4559,6 +4559,32 @@ static void restore_unbound_workers_cpumask(struct worker_pool *pool, int cpu)
> > >           WARN_ON_ONCE(set_cpus_allowed_ptr(worker->task,
> > >                             pool->attrs->cpumask) < 0);
> > >   }
> > > +#ifdef CONFIG_MEMORY_HOTPLUG
> > > +
> > > +static void reflesh_wq_possible_mask(int cpu, int node)
> > > +{
> > > +    int oldnode;
> > > +    for_each_node_state(oldnode, N_POSSIBLE)
> > > +        cpumask_clear_cpu(cpu, wq_numa_possible_cpumask[oldnode]);
> >
> > You need to check and update all the wq->numa_pwq_tbl[oldnode]
>
> you mean : if I drop patch 1/4, it will be required. Right ?
> I'll add that check.

Ah, isn't it handled by wq_update_unbound_numa() called at workqueue_cpu_down_callback() ?
Because node's online cpumask will be empty, new pwq will be attached.

Thanks
-Kame




--
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/