[PATCH 0/8] io-pgtable lock removal

On Wed, Jun 14, 2017 at 05:40:30PM -0700, Ray Jui wrote:

With the NVMf target test with 4 SSDs, fio based test, random read, 4k,
8 jobs:

Without IOMMU:

IOPS = 1080K

With IOMMU, but without your latest patch:

IOPS = 520K

With IOMMU and your latest patch:

IOPS = 500K ~ 850K (a lot of variation observed during the same test run)

That variation might come from the RB-Tree used in the IOVA allocator.
For block-device workloads the allocation size of iova ranges might be
bigger than what is cached in the magazines, so that the fall-back to
the old (locked) allocator is used.


	Joerg