Hi Zi, On Mon, Nov 05, 2018 at 01:49:14PM -0500, Zi Yan wrote: > On 5 Nov 2018, at 11:55, Daniel Jordan wrote: > > Do you think if it makes sense to use ktask for huge page migration (the data > copy part)? It certainly could. > I did some experiments back in 2016[1], which showed that migrating one 2MB page > with 8 threads could achieve 2.8x throughput of the existing single-threaded method. > The problem with my parallel page migration patchset at that time was that it > has no CPU-utilization awareness, which is solved by your patches now. Did you run with fewer than 8 threads? I'd want a bigger speedup than 2.8x for 8, and a smaller thread count might improve thread utilization. It would be nice to multithread at a higher granularity than 2M, too: a range of THPs might also perform better than a single page. Thanks for your comments. > [1]https://lkml.org/lkml/2016/11/22/457