On Thu, Jan 26, 2023 at 02:22:09PM -0800, Andrew Morton wrote: > On Thu, 26 Jan 2023 13:51:13 -0800 Keith Busch <kbusch@xxxxxxxx> wrote: > > > Time spent in dma_pool alloc/free increases linearly with the number of > > pages backing the pool. We can reduce this to constant time with minor > > changes to how free pages are tracked. > > Do we have any performance testing results for realistic workloads? Yes, I mentioned this a little in patch 11, profiling with nvme with high-depth dmapool allocating workloads. Results really depend on your environment, so YMMV, but I was able to observe time spent in dma_pool_{alloc,free}() reduced by half.