Hi Suravee, thanks for working on this.
On Wed, Jan 31, 2018 at 12:01:14AM -0500, Suravee Suthikulpanit wrote: > +static void amd_iommu_iotlb_range_add(struct iommu_domain *domain, > + unsigned long iova, size_t size) > +{ > + struct amd_iommu_flush_entries *entry, *p; > + unsigned long flags; > + bool found = false; > + > + spin_lock_irqsave(&amd_iommu_flush_list_lock, flags); I am not happy with introducing or using global locks when they are not necessary. Can this be a per-domain lock? Besides, did you check it makes sense to actually keep track of the ranges here? My approach would be to just make iotlb_range_add() an noop and do a full domain flush in iotlb_sync(). But maybe you did measurements you can share here to show there is a benefit. Joerg