On Tue, Apr 12, 2022 at 09:43:28PM +0800, Yanjun Zhu wrote: > 在 2022/4/11 19:50, Jason Gunthorpe 写道: > > On Mon, Apr 11, 2022 at 04:00:18PM -0400, yanjun.zhu@xxxxxxxxx wrote: > > > @@ -138,8 +139,10 @@ void *rxe_alloc(struct rxe_pool *pool) > > > elem->obj = obj; > > > kref_init(&elem->ref_cnt); > > > - err = xa_alloc_cyclic(&pool->xa, &elem->index, elem, pool->limit, > > > - &pool->next, GFP_KERNEL); > > > + xa_lock_irqsave(&pool->xa, flags); > > > + err = __xa_alloc_cyclic(&pool->xa, &elem->index, elem, pool->limit, > > > + &pool->next, GFP_ATOMIC); > > > + xa_unlock_irqrestore(&pool->xa, flags); > > > > No to using atomics, this needs to be either the _irq or _bh varient > > If I understand you correctly, you mean that we should use > xa_lock_irq/xa_unlock_irq or xa_lock_bh/xa_unlock_bh instead of > xa_unlock_irqrestore? This is correct > If so, xa_lock_irq/xa_unlock_irq or xa_lock_bh/xa_unlock_bh is used here, > the warning as below will appear. This means that __rxe_add_to_pool disables > softirq, but fpu_clone enables softirq. I don't know what this is, you need to show the whole debug. fpu_clone does not call rxe_add_to_pool > As such, it is better to use xa_unlock_irqrestore + > __xa_alloc(...,GFP_ATOMIC/GFP_NOWAIT). No Jason
