Hi Josef, Thanks for taking a look.
On Mon, Aug 21 2017 at 17:26, Josef Bacik wrote: > On Mon, Aug 21, 2017 at 04:21:28PM +0100, Brendan Jackman wrote: [...] >> - local_group = cpumask_test_cpu(this_cpu, >> - sched_group_span(group)); >> - > > This isn't right is it? cpu isn't necessarily in the very first group of a sd > right? I think it is - I haven't grokked the sd/sg setup code in kernel/sched/topology.c but there is a comment[1] that I interpret as saying this. I'll take a more careful look tomorrow. [1] http://elixir.free-electrons.com/linux/v4.13-rc6/source/kernel/sched/topology.c#L786 If I'm wrong, this can be rewritten not to use that assumption - I did it this way in the caller ("else if (group == sd->groups)") because I didn't want to use cpumask_test_cpu, and then changed it inside find_idlest_group so there weren't two ways of doing the same thing in the same neighbourhood of code. Cheers, Brendan
