Re: [PATCH 2/2] iommu/iova: Improve restart logic

2021-03-18 Thread John Garry
Well yeah, in your particular case you're allocating from a heavily over-contended address space, so much of the time it is genuinely full. Plus you're primarily churning one or two sizes of IOVA, so there's a high chance that you will either allocate immediately from the cached node (after a

Re: [PATCH 2/2] iommu/iova: Improve restart logic

2021-03-18 Thread Robin Murphy
On 2021-03-18 11:38, John Garry wrote: On 10/03/2021 17:47, John Garry wrote: On 09/03/2021 15:55, John Garry wrote: On 05/03/2021 16:35, Robin Murphy wrote: Hi Robin, When restarting after searching below the cached node fails, resetting the start point to the anchor node is often overly pe

Re: [PATCH 2/2] iommu/iova: Improve restart logic

2021-03-18 Thread John Garry
On 10/03/2021 17:47, John Garry wrote: On 09/03/2021 15:55, John Garry wrote: On 05/03/2021 16:35, Robin Murphy wrote: Hi Robin, When restarting after searching below the cached node fails, resetting the start point to the anchor node is often overly pessimistic. If allocations are made with

Re: [PATCH 2/2] iommu/iova: Improve restart logic

2021-03-09 Thread John Garry
On 05/03/2021 16:35, Robin Murphy wrote: Hi Robin, When restarting after searching below the cached node fails, resetting the start point to the anchor node is often overly pessimistic. If allocations are made with mixed limits - particularly in the case of the opportunistic 32-bit allocation f