Re: [PATCH net-next] net: wwan: t7xx: fix GFP_KERNEL usage in spin_lock context

[Sergey Ryazanov]

Hello Ziyang,

On Sat, May 14, 2022 at 11:57 AM Ziyang Xuan
<william.xuanziyang@xxxxxxxxxx> wrote:
> t7xx_cldma_clear_rxq() call t7xx_cldma_alloc_and_map_skb() in spin_lock
> context, But __dev_alloc_skb() in t7xx_cldma_alloc_and_map_skb() uses
> GFP_KERNEL, that will introduce scheduling factor in spin_lock context.
>
> Replace GFP_KERNEL with GFP_ATOMIC to fix it.

Would not it will be more reliable to just rework
t7xx_cldma_clear_rxq() to avoid calling t7xx_cldma_alloc_and_map_skb()
under the spin lock instead of doing each allocation with GFP_ATOMIC?
E.g. t7xx_cldma_gpd_rx_from_q() calls t7xx_cldma_alloc_and_map_skb()
avoiding any lock holding.

-- 
Sergey