Re: [PATCH v11 01/12] iova: Export alloc_iova_fast() and free_iova_fast()

[John Garry]

On 25/08/2021 10:55, Will Deacon wrote:
> On Tue, Aug 24, 2021 at 02:08:33PM -0400, Michael S. Tsirkin wrote:
> > On Wed, Aug 18, 2021 at 08:06:31PM +0800, Xie Yongji wrote:
> > > Export alloc_iova_fast() and free_iova_fast() so that
> > > some modules can make use of the per-CPU cache to get
> > > rid of rbtree spinlock in alloc_iova() and free_iova()
> > > during IOVA allocation.
> > >
> > > Signed-off-by: Xie Yongji <xieyongji@xxxxxxxxxxxxx>
> >
> >
> > This needs ack from iommu maintainers. Guys?
>
> Looks fine to me:
>
> Acked-by: Will Deacon <will@xxxxxxxxxx>
>
> Will
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JFYI, There was a preliminary discussion to move the iova rcache code 
(which the iova fast alloc and free functions are based on) out of the 
iova code and maybe into dma-iommu (being the only user). There was 
other motivation.

https://lore.kernel.org/linux-iommu/83de3911-145d-77c8-17c1-981e4ff825d3@xxxxxxx/

Having more users complicates that...

Thanks,
John