Messages in this thread | | | Date | Fri, 18 Jul 2014 16:16:48 +0200 | From | Peter Zijlstra <> | Subject | Re: Scheduler regression from caffcdd8d27ba78730d5540396ce72ad022aff2c |
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On Fri, Jul 18, 2014 at 08:01:26AM -0500, Bruno Wolff III wrote: > build_sched_domain: cpu: 0 level: SMT cpu_map: 0-3 tl->mask: 0,2 > [ 0.254433] build_sched_domain: cpu: 0 level: MC cpu_map: 0-3 tl->mask: 0 > [ 0.254516] build_sched_domain: cpu: 0 level: DIE cpu_map: 0-3 tl->mask: 0-3 > [ 0.254600] build_sched_domain: cpu: 1 level: SMT cpu_map: 0-3 tl->mask: 1,3 > [ 0.254683] build_sched_domain: cpu: 1 level: MC cpu_map: 0-3 tl->mask: 1 > [ 0.254766] build_sched_domain: cpu: 1 level: DIE cpu_map: 0-3 tl->mask: 0-3 > [ 0.254850] build_sched_domain: cpu: 2 level: SMT cpu_map: 0-3 tl->mask: 0,2 > [ 0.254932] build_sched_domain: cpu: 2 level: MC cpu_map: 0-3 tl->mask: 2 > [ 0.255005] build_sched_domain: cpu: 2 level: DIE cpu_map: 0-3 tl->mask: 0-3 > [ 0.255091] build_sched_domain: cpu: 3 level: SMT cpu_map: 0-3 tl->mask: 1,3 > [ 0.255176] build_sched_domain: cpu: 3 level: MC cpu_map: 0-3 tl->mask: 3 > [ 0.255260] build_sched_domain: cpu: 3 level: DIE cpu_map: 0-3 tl->mask: 0-3
*blink*...
That's, shall we say, unexpected. Let me ponder that a bit. HPA any clue why a machine might report such a weird topology? AFAIK threads _always_ share cache. So how can cpu_coregroup_mask be a subset (instead of a superset) of topology_thread_cpumask?
Let me go stare at the x86 topology mask setup code.
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