On 2017/7/19 18:23, Robin Murphy wrote: > On 19/07/17 09:37, Ard Biesheuvel wrote: >> On 18 July 2017 at 17:57, Robin Murphy <robin.mur...@arm.com> wrote: >>> Hi all, >>> >>> In the wake of the ARM SMMU optimisation efforts, it seems that certain >>> workloads (e.g. storage I/O with large scatterlists) probably remain quite >>> heavily influenced by IOVA allocation performance. Separately, Ard also >>> reported massive performance drops for a graphical desktop on AMD Seattle >>> when enabling SMMUs via IORT, which we traced to dma_32bit_pfn in the DMA >>> ops domain getting initialised differently for ACPI vs. DT, and exposing >>> the overhead of the rbtree slow path. Whilst we could go around trying to >>> close up all the little gaps that lead to hitting the slowest case, it >>> seems a much better idea to simply make said slowest case a lot less slow. >>> >>> I had a go at rebasing Leizhen's last IOVA series[1], but ended up finding >>> the changes rather too hard to follow, so I've taken the liberty here of >>> picking the whole thing up and reimplementing the main part in a rather >>> less invasive manner. >>> >>> Robin. >>> >>> [1] >>> https://www.mail-archive.com/iommu@lists.linux-foundation.org/msg17753.html >>> >>> Robin Murphy (1): >>> iommu/iova: Extend rbtree node caching >>> >>> Zhen Lei (3): >>> iommu/iova: Optimise rbtree searching >>> iommu/iova: Optimise the padding calculation >>> iommu/iova: Make dma_32bit_pfn implicit >>> >>> drivers/gpu/drm/tegra/drm.c | 3 +- >>> drivers/gpu/host1x/dev.c | 3 +- >>> drivers/iommu/amd_iommu.c | 7 +-- >>> drivers/iommu/dma-iommu.c | 18 +------ >>> drivers/iommu/intel-iommu.c | 11 ++-- >>> drivers/iommu/iova.c | 112 >>> ++++++++++++++++----------------------- >>> drivers/misc/mic/scif/scif_rma.c | 3 +- >>> include/linux/iova.h | 8 +-- >>> 8 files changed, 60 insertions(+), 105 deletions(-) >>> >> >> These patches look suspiciously like the ones I have been using over >> the past couple of weeks (modulo the tegra and host1x changes) from >> your git tree. They work fine on my AMD Overdrive B1, both in DT and >> in ACPI/IORT modes, although it is difficult to quantify any >> performance deltas on my setup. > > Indeed - this is a rebase (to account for those new callers) with a > couple of trivial tweaks to error paths and corner cases that normal > usage shouldn't have been hitting anyway. "No longer unusably awful" is > a good enough performance delta for me :) > >> Tested-by: Ard Biesheuvel <ard.biesheu...@linaro.org> I got the same performance data compared with my patch version. It works well.
Tested-by: Zhen Lei <thunder.leiz...@huawei.com> > > Thanks! > > Robin. > > . > -- Thanks! BestRegards