On Thu, Jul 20, 2017 at 10:21:18PM +0100, Mel Gorman wrote: > This is a second round of performance-related backports based on low-hanging > fruit in the 4.13 merge window based on 4.12.2. > > As before, these have only been tested on 4.12-stable. While they may > merge against older kernels, I have no data on how it behaves and cannot > guarantee it's a good idea so I don't recommend it. There will also be > some major conflicts that are not trivial to resolve. > > For most of the tests I conducted, the impact is marginal but patches the > first two sets of patches are important for large machines and for uses > of nohz_full. The load balancing patch is fairly specific but measurable. > The removal of unnecessary IRQ disabling/enabling is borderline in terms of > performance but they are trivial patches and avoiding unnecessary expensive > operations is always a plus. > With 4.12.3, the patches 1-17 can be dropped. The main commit left over that is missing from this series was "sched/topology: Fix overlapping sched_group_capacity" which is relatively minor in impact. The rest were to bring the schedulers more or less in line so debugging problems in 4.12-stable would be easier to compare with mainline and to make the 4.12 scheduler easier to understand. The rest of the series should apply ok on top of 4.12.3 if you'd like to pick it up. -- Mel Gorman SUSE Labs