Messages in this thread | | | Subject | Re: [PATCH v2 3/3] arm64: disable ACPI PPTT support temporarily | From | Jeremy Linton <> | Date | Tue, 5 Jun 2018 11:38:28 -0500 |
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Hi,
On 06/05/2018 10:27 AM, Sudeep Holla wrote: > > > On 05/06/18 16:02, Rafael J. Wysocki wrote: >> On Tue, Jun 5, 2018 at 4:35 PM, Sudeep Holla <sudeep.holla@arm.com> wrote: >>> Currently, ARM64 doesn't support updating the CPU topology masks on >>> CPU hotplug operations. ACPI PPTT support rely on that missing feature >>> which is technically not incorrect. Instead of reverting all the PPTT >>> support, let's keep it simple and disable ACPI PPTT support on ARM64 >>> for time-being until the topology updates are added for CPU hotplug >>> operations. >> >> When is that going to happen? >>> Nobody else uses PPTT now. >> > > No we need it on ARM64. I have even the fixes for the original issue > but it's bit invasive and too late as we are already in the merge > window. It needs to be tested on NUMA platforms, I have asked for that > explicitly. >
So, there is a lot simpler fix for this, and its to remove the numa mask dependency from the scheduler domain building. That is just a couple line fix, and it reverts !ACPI to its original behavior, while the ACPI LLC building will work around the NUMA in package issue that caused patch 12/12 as the machine in question doesn't have a LLC crossing numa domains.
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