From mboxrd@z Thu Jan 1 00:00:00 1970 From: sudeep.holla@arm.com (Sudeep Holla) Date: Fri, 29 Jun 2018 11:29:27 +0100 Subject: [PATCH] arm64: acpi: reenumerate topology ids In-Reply-To: <20180628173243.obydzakh2stfs26w@kamzik.brq.redhat.com> References: <20180628145128.10057-1-drjones@redhat.com> <20180628173243.obydzakh2stfs26w@kamzik.brq.redhat.com> Message-ID: <20180629102927.GA18043@e107155-lin> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thu, Jun 28, 2018 at 07:32:43PM +0200, Andrew Jones wrote: > On Thu, Jun 28, 2018 at 05:30:51PM +0100, Sudeep Holla wrote: > > I am not sure if we can ever guarantee that DT and ACPI will get the > > same ids whatever counter we use as it depends on the order presented in > > the firmware(DT or ACPI). So I am not for generating ids for core and > > threads in that way. > > I don't believe we have to guarantee that the exact (package,core,thread) > triplet describing a PE with DT matches ACPI. We just need to guarantee > that each triplet we select properly puts a PE in the same group as its > peers. So, as long as we keep the grouping described by DT or ACPI, then > the (package,core,thread) IDs assigned are pretty arbitrary. > If that's the requirement, we already do that. The IDs are just too arbitrary :) > I could change the commit message to state we can generate IDs *like* > DT does (i.e. with counters), even if they may not result in identical > triplet to PE mappings. > Why we need to make it *like DT* ? > > > > So I would like to keep it simple and just have this counters for > > package ids as demonstrated in Shunyong's patch. > > > > If we don't also handle cores when there are threads, then the cores > will also end up having weird IDs. > Yes, but if PPTT says it has valid ID, I would prefer that over DT like generated. -- Regards, Sudeep