| Message ID | 1528209304-3280-3-git-send-email-sudeep.holla@arm.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v2,1/3] Revert "arm64: topology: divorce MC scheduling domain from core_siblings" | expand |
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. -- Regards, Sudeep -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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. -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 9fd4a8ccce07..98a5c78a80f9 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -7,7 +7,6 @@ config ARM64 select ACPI_REDUCED_HARDWARE_ONLY if ACPI select ACPI_MCFG if ACPI select ACPI_SPCR_TABLE if ACPI - select ACPI_PPTT if ACPI select ARCH_CLOCKSOURCE_DATA select ARCH_HAS_DEBUG_VIRTUAL select ARCH_HAS_DEVMEM_IS_ALLOWED
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. Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> --- arch/arm64/Kconfig | 1 - 1 file changed, 1 deletion(-) -- 2.7.4 -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html