Messages in this thread | | | From | 王擎 <> | Subject | [PATCH] arch_topology: support parsing cache topology from DT | Date | Thu, 7 Apr 2022 03:11:51 +0000 |
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>> From: wangqing <11112896@bbktel.com> >> >> When ACPI is not enabled, we can parse cache topolopy from DT: >> * cpu0: cpu@000 { >> * next-level-cache = <&L2_1>; >> * L2_1: l2-cache { >> * compatible = "cache"; >> * next-level-cache = <&L3_1>; >> * }; >> * L3_1: l3-cache { >> * compatible = "cache"; >> * }; >> * }; >> * >> * cpu1: cpu@001 { >> * next-level-cache = <&L2_1>; >> * }; >> * cpu2: cpu@002 { >> * L2_2: l2-cache { >> * compatible = "cache"; >> * next-level-cache = <&L3_1>; >> * }; >> * }; >> * >> * cpu3: cpu@003 { >> * next-level-cache = <&L2_2>; >> * }; >> cache_topology hold the pointer describing "next-level-cache", >> it can describe the cache topology of every level. >> >> Expand the use of llc_sibling when ACPI is not enabled. >> > >You seem to have posted this patch as part of the series first. One patch >was rejected and then you post this without any history. It confuses if you >don't provide all the background/history.
Yes, the series contains several parts, the sched_domain part was rejected temporary. But it has nothing to do with this patch, that's why I took it apart. The background doesn't matter, let's focus on this patch itself.
> >Having said that, NACK for this patch as it stands. We have >drivers/base/cacheinfo.c which has all the parsing of cache information. >IIRC we already consider LLC but highlight if anything is particularly >missing. I am unable to follow/understand with you commit message.
cacheinfo.c just describes the properties of the cache, It can't describe the cache topology, some like cpuinfo and cpu topology.
llc_sibling is not used at all if ACPI is not enabled, because llc_id always be -1, and cpu_coregroup_mask() always return the core_sibling.
Why not get the cache topology from DT if the arch support GENERIC_ARCH_TOPOLOGY.
Thanks, Wang
> >-- >Regards, >Sudeep
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