Re: [PATCH 3/3] iommu/dma: Avoid unlikely high-order allocations

On Fri, 2015-12-18 at 14:35 -0800, Doug Anderson wrote: > Robin, > > On Fri, Dec 18, 2015 at 9:01 AM, Robin Murphy wrote: > > Doug reports that the equivalent page allocator on 32-bit ARM exhibits > > particularly pathalogical behaviour under memory pressure when > >

[PATCH 3/3] iommu/dma: Avoid unlikely high-order allocations

Doug reports that the equivalent page allocator on 32-bit ARM exhibits particularly pathalogical behaviour under memory pressure when fragmentation is high, where allocating a 4MB buffer takes tens of seconds and the number of calls to alloc_pages() is over 9000![1] We can drastically improve

Re: [PATCH 3/3] iommu/dma: Avoid unlikely high-order allocations

Robin, On Fri, Dec 18, 2015 at 9:01 AM, Robin Murphy wrote: > Doug reports that the equivalent page allocator on 32-bit ARM exhibits > particularly pathalogical behaviour under memory pressure when > fragmentation is high, where allocating a 4MB buffer takes tens of >