On Thu, Nov 01, 2018 at 02:35:00PM -0700, Nicolin Chen wrote: > The __GFP_ZERO will be passed down to the generic page allocation > routine which zeros everything page by page. This is safe to be a > generic way but not efficient for iommu allocation that organizes > contiguous pages using scatterlist. > > So this changes drops __GFP_ZERO from the flag, and adds a manual > memset after page/sg allocations, using the length of scatterlist. > > My test result of a 2.5MB size allocation shows iommu_dma_alloc() > takes 46% less time, reduced from averagely 925 usec to 500 usec.
And in what case does dma_alloc_* performance even matter? _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
