mirror of
https://github.com/torvalds/linux.git
synced 2026-02-04 15:28:49 +08:00
bfcc439743
Currently the cluster identifier is not set on DT based platforms. The reset or default value is -1 for all the CPUs. Once we assign the cluster identifier values correctly, the cluster_sibling mask will be populated and returned by cpu_clustergroup_mask() to contribute in the creation of the CLS scheduling domain level, if SCHED_CLUSTER is enabled. To avoid topologies that will result in questionable or incorrect scheduling domains, impose restrictions regarding the span of clusters, as presented to scheduling domains building code: cluster_sibling should not span more or the same CPUs as cpu_coregroup_mask(). This is needed in order to obtain a strict separation between the MC and CLS levels, and maintain the same domains for existing platforms in the presence of CONFIG_SCHED_CLUSTER, where the new cluster information is redundant and irrelevant for the scheduler. While previously the scheduling domain builder code would have removed MC as redundant and kept CLS if SCHED_CLUSTER was enabled and the cpu_coregroup_mask() and cpu_clustergroup_mask() spanned the same CPUs, now CLS will be removed and MC kept. Link: https://lore.kernel.org/r/20220704101605.1318280-18-sudeep.holla@arm.com Cc: Darren Hart <darren@os.amperecomputing.com> Tested-by: Conor Dooley <conor.dooley@microchip.com> Acked-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>