Comment 12 for bug 1828248

@longli I would like your assessment of the changes that we've made here to get back to expected performance. I know we are not getting the same results on NVMe devices with 16.04 and 18.04 and I'm wondering if there's something substantially different with the 4.15 kernel in use on 16.04 that prevents us from making the same changes that we did with 4.18 to get better performance.