Subject: [PATCH 0/8] io-pgtable lock removal

From: [email-masked] (Joerg Roedel)
Date: Wed, 21 Jun 2017 17:47:26 +0200

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