Messages in this thread | | | Subject | Re: [PATCH 1/4] sched/topology: SD_ASYM_CPUCAPACITY flag detection | From | Qais Yousef <> | Date | Tue, 24 Jul 2018 09:59:21 +0100 |
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On 24/07/18 09:37, Morten Rasmussen wrote: > On Mon, Jul 23, 2018 at 05:07:50PM +0100, Qais Yousef wrote: >> On 23/07/18 16:27, Morten Rasmussen wrote: >>> It does increase the cost of things like hotplug slightly and >>> repartitioning of root_domains a slightly but I don't see how we can >>> avoid it if we want generic code to set this flag. If the costs are not >>> acceptable I think the only option is to make the detection architecture >>> specific. >> I think hotplug is already expensive and this overhead would be small in >> comparison. But this could be called when frequency changes if I understood >> correctly - this is the one I wasn't sure how 'hot' it could be. I wouldn't >> expect frequency changes at a very high rate because it's relatively >> expensive too.. > A frequency change shouldn't lead to a flag change or a rebuild of the > sched_domain hierarhcy. The situations where the hierarchy should be > rebuild to update the flag is during boot as we only know the amount of > asymmetry once cpufreq has been initialized, when cpus are hotplugged > in/out, and when root_domains change due to cpuset reconfiguration. So > it should be a relatively rare event.
Ah OK I misunderstood that part then.
The series LGTM then.
-- Qais Yousef
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