[PATCH] iommu/iova: Free all CPU rcache for retry when iova alloc failure

[yf.wang at mediatek.com]

On Fri, 2022-03-04 at 14:03 +0000, Robin Murphy wrote:
> 
> OK, so either there's a mystery bug where IOVAs somehow get freed on 
> offline CPUs, or the hotplug notifier isn't working correctly, or
> you've 
> contrived a situation where alloc_iova_fast() is actually racing
> against 
> iova_cpuhp_dead(). In the latter case, the solution is "don't do
> that".
> 
> This change should not be necessary.
> 
> Thanks,
> Robin.

Hi Robin,

You are right, kernel 5.15 already has this patch, but kernel 5.10
not contain.

Thanks,
Yunfei.