[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] RE: [XEN RFC PATCH 07/40] xen/arm: use !CONFIG_NUMA to keep fake NUMA API
Hi Julien, > -----Original Message----- > From: Julien Grall <julien@xxxxxxx> > Sent: 2021年8月20日 19:24 > To: Wei Chen <Wei.Chen@xxxxxxx>; xen-devel@xxxxxxxxxxxxxxxxxxxx; > sstabellini@xxxxxxxxxx > Cc: Bertrand Marquis <Bertrand.Marquis@xxxxxxx> > Subject: Re: [XEN RFC PATCH 07/40] xen/arm: use !CONFIG_NUMA to keep fake > NUMA API > > > > On 20/08/2021 11:24, Wei Chen wrote: > > Hi Julien, > > Hi Wei, > > > > >> -----Original Message----- > >> From: Julien Grall <julien@xxxxxxx> > >> Sent: 2021年8月20日 16:24 > >> To: Wei Chen <Wei.Chen@xxxxxxx>; xen-devel@xxxxxxxxxxxxxxxxxxxx; > >> sstabellini@xxxxxxxxxx; jbeulich@xxxxxxxx > >> Cc: Bertrand Marquis <Bertrand.Marquis@xxxxxxx> > >> Subject: Re: [XEN RFC PATCH 07/40] xen/arm: use !CONFIG_NUMA to keep > fake > >> NUMA API > >> > >> > >> > >> On 20/08/2021 03:08, Wei Chen wrote: > >>> Hi Julien, > >> > >> Hi Wei, > >> > >>> > >>>> -----Original Message----- > >>>> From: Julien Grall <julien@xxxxxxx> > >>>> Sent: 2021年8月19日 21:34 > >>>> To: Wei Chen <Wei.Chen@xxxxxxx>; xen-devel@xxxxxxxxxxxxxxxxxxxx; > >>>> sstabellini@xxxxxxxxxx; jbeulich@xxxxxxxx > >>>> Cc: Bertrand Marquis <Bertrand.Marquis@xxxxxxx> > >>>> Subject: Re: [XEN RFC PATCH 07/40] xen/arm: use !CONFIG_NUMA to keep > >> fake > >>>> NUMA API > >>>> > >>>> Hi Wei, > >>>> > >>>> On 11/08/2021 11:23, Wei Chen wrote: > >>>>> Only Arm64 supports NUMA, the CONFIG_NUMA could not be > >>>>> enabled for Arm32. > >>>> > >>>> What do you mean by "could not be enabled"? > >>> > >>> I have not seen any Arm32 hardware support NUMA, so I think > >>> we don't need to support Arm32 NUMA. > >> > >> I understand that there may not be 32-bit platform with NUMA. And > that's > >> fine stating that in the commit message. However... > >> > >>> In this case, this Kconfig > >>> option could not be enabled on Arm32. > >> > >> ... you continue to say "couldn't be enabled" without clarifying > whether > >> this mean that the build will break or this was just not tested because > >> you don't have any platform. > > > > Ok, I understand your concern. Yes, my words would lead to mis- > understanding. > > If we make CONFIG_NUMA enabled in Arm32, it need Arm32 to implement some > > code to support NUMA common code. Otherwise the Arm32 build will failed. > > When I skimmed through the series, most of the code seems to be either > in common, arm (bitness neutral). So I am not quite too sure why it > would not build. Do you have more details? > It could not build because I have not tried to enable device_tree_numa option for Arm32 but enabled NUMA for arm32. I have tested it again, yes, simple enable device_tree_numa and NUMA for arm32 can build a image successfully. So, I think it's OK to enable this on Arm32, and I will do it in next version. But, can we still keep these FAKE APIs? If user don't want to enable NUMA they still can make Xen work? And I will remove "could not enable for Arm32" from commit log. > > I have not tried to implement those code for Arm32. And I found there is > > no Arm32 machine support NUMA, so I wanted Arm32 to use fake NUMA API > > as before. > > > >> > >> To put it differently, the code for NUMA looks bitness neutral. So I > >> cannot really what what prevent us to potentially use it on Arm 32-bit. > >> > > > > Yes, you're right, it's neutral. But do we really need to add code to an > > ARCH that it may never use? > > Technically you already added the code because arch/arm/ is common > between arm32 and arm64. My only ask is to not make the new config > depends on arm64. If you only build test it that fine because... > > And how can we test this code? > > I don't expect any of the code to be an issue on arm32 as the code > should mostly be arch neutral. I mean, we don't have Arm32 NUMA machine to test, I don't know the code works well on Arm32 NUMA or not. I only can verify them on non-NUMA arm32, and make sure this code will not break existed machines. > > Cheers, > > -- > Julien Grall
|
![]() |
Lists.xenproject.org is hosted with RackSpace, monitoring our |