On Tue, 3 Mar 2020 at 23:17, Yang Shi <shy828301@xxxxxxxxx> wrote:
>
> On Tue, Mar 3, 2020 at 2:53 AM Tetsuo Handa
> <penguin-kernel@xxxxxxxxxxxxxxxxxxx> wrote:
> >
> > Hello, Naresh.
> >
> > > [ 98.003346] WARNING: CPU: 2 PID: 340 at
> > > include/linux/sched/mm.h:323 alloc_page_buffers+0x210/0x288
<Trim>
> >
> Could you please try the below debug patch? This is not the proper
> fix, but it may help us narrow down the problem.
>
> diff --git a/include/linux/sched/mm.h b/include/linux/sched/mm.h
> index c49257a..1cc1cdc 100644
> --- a/include/linux/sched/mm.h
> +++ b/include/linux/sched/mm.h
> @@ -320,6 +320,10 @@ static inline void
> memalloc_nocma_restore(unsigned int flags)
> */
> static inline void memalloc_use_memcg(struct mem_cgroup *memcg)
> {
> + if ((current->flags & PF_KTHREAD) &&
> + current->active_memcg)
> + return;
> +
> WARN_ON_ONCE(current->active_memcg);
> current->active_memcg = memcg;
> }
After applying this patch the reported "warning" did not happen.
Here is the full test log.
https://lkft.validation.linaro.org/scheduler/job/1265325#L1287
- Naresh
