Hi Julien, > -----Original Message----- > From: Julien Grall <[email protected]> > Sent: 2021年8月20日 16:41 > To: Wei Chen <[email protected]>; [email protected]; > [email protected]; [email protected] > Cc: Bertrand Marquis <[email protected]> > Subject: Re: [XEN RFC PATCH 17/40] xen/arm: Introduce DEVICE_TREE_NUMA > Kconfig for arm64 > > On 20/08/2021 03:30, Wei Chen wrote: > > Hi Julien, > > Hi Wei, > > >> -----Original Message----- > >> From: Julien Grall <[email protected]> > >> Sent: 2021年8月19日 21:38 > >> To: Wei Chen <[email protected]>; [email protected]; > >> [email protected]; [email protected] > >> Cc: Bertrand Marquis <[email protected]> > >> Subject: Re: [XEN RFC PATCH 17/40] xen/arm: Introduce DEVICE_TREE_NUMA > >> Kconfig for arm64 > >> > >> Hi, > >> > >> On 11/08/2021 11:24, Wei Chen wrote: > >>> We need a Kconfig option to distinguish with ACPI based > >>> NUMA. So we introduce the new Kconfig option: > >>> DEVICE_TREE_NUMA in this patch for Arm64. > >>> > >>> Signed-off-by: Wei Chen <[email protected]> > >>> --- > >>> xen/arch/arm/Kconfig | 10 ++++++++++ > >>> 1 file changed, 10 insertions(+) > >>> > >>> diff --git a/xen/arch/arm/Kconfig b/xen/arch/arm/Kconfig > >>> index ecfa6822e4..678cc98ea3 100644 > >>> --- a/xen/arch/arm/Kconfig > >>> +++ b/xen/arch/arm/Kconfig > >>> @@ -33,6 +33,16 @@ config ACPI > >>> Advanced Configuration and Power Interface (ACPI) support > for Xen > >> is > >>> an alternative to device tree on ARM64. > >>> > >>> +config DEVICE_TREE_NUMA > >> > >> The name suggests that NUMA should only be enabled for Device-Tree... > >> But the description looks generic. > >> > >> However, I think the user should only have the choice to say whether > >> they want NUMA to be enabled or not. We should not give them the choice > >> to enable/disable the parsing for DT/ACPI. > >> > >> So we should have a generic config that will then select DT (and ACPI > in > >> the future). > >> > > > > How about we select DT_NUMA default on Arm64. And DT_NUMA select NUMA > > like what we have done in patch#6 in x86? And remove the description? > I would rather not make NUMA supported by default on Arm64. Instead, we > should go throught the same process as other new features and gate it > behind UNSUPPORTED until it is mature enough. >
Ok. I agree with this. > > > > If we make generic NUMA as a selectable option, and depends on > > NUMA to select DT or ACPI NUMA. It seems to be quite different from > > the existing logic? > > I am a bit confused. You added just logic to select NUMA from ACPI, > right? So are you talking about a different logic? > No, I didn't want a different one. I thought you wanted it that way. Obviously, I mis-understanded your comments. Can I understand your previous comments like following: 1. We should have a generic config that will then select DT and ACPI: Because we already have CONFIG_NUMA in common layer. So we need to add another one for Arm like CONFIG_ARM_NUMA? And in this option, we can select CONFIG_DEVICE_TREE_NUMA automatically if device tree is enabled. If CONFIG_ACPI is enabled, we will select CONFIG_ACPI_NUMA too (in the future) In Xen code, DT_NUMA and ACPI_NUMA code can co-exist, Xen will check the system ACPI support status to decide to use DT_NUMA or ACPI_NUMA? > Cheers, > > -- > Julien Grall
