Hi, On 2017/12/18 20:42, Morten Rasmussen wrote: > On Fri, Dec 15, 2017 at 10:36:35AM -0600, Jeremy Linton wrote: >> Hi, >> >> On 12/13/2017 12:02 PM, Lorenzo Pieralisi wrote: >>> [+Morten, Dietmar] >>> >>> $SUBJECT should be: >>> >>> arm64: topology: rename cluster_id >> [cut] >> >> I was hoping someone else would comment here, but my take at this point is >> that it doesn't really matter in a functional sense at the moment. >> Like the chiplet discussion it can be the subject of a future patch along >> with the patches which tweak the scheduler to understand the split. >> >> BTW, given that i'm OoO next week, and the following that are the holidays, >> I don't intend to repost this for a couple weeks. I don't think there are >> any issues with this set. >> >>> >>> There is also arch/arm to take into account, again, this patch is >>> just renaming (as it should have named since the beginning) a >>> topology level but we should consider everything from a legacy >>> perspective. > > arch/arm has gone for thread/core/socket for the three topology levels > it supports. > > I'm not sure what short term value keeping cluster_id has? Isn't it just > about where we make the package = cluster assignment? Currently it is in > the definition of topology_physical_package_id. If we keep cluster_id > and add package_id, it gets moved into the MPIDR/DT parsing code. > > Keeping cluster_id and introducing a topology_cluster_id function could > help cleaning up some of the users of topology_physical_package_id that > currently assumes package_id == cluster_id though. I think we still need the information describing which cores are in one cluster. Many arm64 chips have the architecture core/cluster/socket. Cores in one cluster may share a same L2 cache. That information can be used to build the sched_domain. If we put cores in one cluster in one sched_domain, the performance will be better.(please see kernel/sched/topology.c:1197, cpu_coregroup_mask() uses 'core_sibling' to build a multi-core sched_domain) So I think we still need variable to record which cores are in one sched_domain for future use. Thanks, Xiongfeng > > Morten > > . > -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
