Re: [PATCH] memcg: Don't call schedule_work when no spinning is allowed

[Shakeel Butt]

On Mon, Aug 31, 2026 at 04:43:39PM -0700, David Stevens wrote:
> Memcg charging can be done from any context, but calling schedule_work()
> isn't safe from an NMI. If memory.high is breached from a context where
> spinning isn't allowed, use irq_work to schedule the reclaim work.
> 
> Fixes: 3ac4638a734a ("memcg: make memcg_rstat_updated nmi safe")
> Signed-off-by: David Stevens <stevensd@xxxxxxxxxx>

Did you hit this issue or just code inspection? I assume this is the
done_restock code path.

> ---
>  include/linux/memcontrol.h |  1 +
>  mm/memcontrol.c            | 12 +++++++++++-
>  2 files changed, 12 insertions(+), 1 deletion(-)
> 
> diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
> index 8170bb8066a2..036d973ceca6 100644
> --- a/include/linux/memcontrol.h
> +++ b/include/linux/memcontrol.h
> @@ -219,6 +219,7 @@ struct mem_cgroup {
>  	spinlock_t	 peaks_lock;
>  
>  	/* Range enforcement for interrupt charges */
> +	struct irq_work high_irq_work;

Instead of adding more complexity, let's just return if we can not spin on
done_restock path.