Re: [PATCH] iommu/amd: flush not present cache in iommu_map_page

[Christoph Hellwig]

On Wed, Apr 24, 2019 at 03:47:39PM +0100, Tom Murphy wrote:
> >And I'd really like to understand the unlikely - amd_iommu_np_cache
> >is set based on a hardware capability, so it seems rather odd to mark
> >it unlikely.  Dynamic branch prediction really should do the right thing
> >here usually.
> 
> Here is the commit which added it without any explanation:
> https://github.com/torvalds/linux/commit/270cab2426cdc6307725e4f1f46ecf8ab8e69193
> 
> should we remove it seen as there's no explanation given ?

I'd be tempted to do that.  But lets just ask Joerg if he has
any opinion..