[Intel-gfx] [PATCH v3 2/2] iommu: Remove cpu-local spinlock

[Joerg Roedel]

On Wed, Jun 01, 2016 at 12:10:09PM +0100, Chris Wilson wrote:
> By avoiding cross-CPU usage of the per-cpu iova cache, we can forgo
> having a spinlock inside the per-cpu struct. The only place where we
> actually may touch another CPU's data is when performing a cache flush
> after running out of memory. Here, we can instead schedule a task to run
> on the other CPU to do the flush before trying again.

The big benefit of the spinlock is that the rcache can be flushed from a
different cpu without the need to send IPIs to everyone.


	Joerg