RE: [PATCH v9 02/13] x86/resctrl: Add a new resource type RDT_RESOURCE_SMBA

[Moger, Babu]

[AMD Official Use Only - General]

Hi Reinette,

> -----Original Message-----
> From: Reinette Chatre <reinette.chatre@xxxxxxxxx>
> Sent: Thursday, December 15, 2022 11:11 AM
> To: Moger, Babu <Babu.Moger@xxxxxxx>; corbet@xxxxxxx;
> tglx@xxxxxxxxxxxxx; mingo@xxxxxxxxxx; bp@xxxxxxxxx
> Cc: fenghua.yu@xxxxxxxxx; dave.hansen@xxxxxxxxxxxxxxx; x86@xxxxxxxxxx;
> hpa@xxxxxxxxx; paulmck@xxxxxxxxxx; akpm@xxxxxxxxxxxxxxxxxxxx;
> quic_neeraju@xxxxxxxxxxx; rdunlap@xxxxxxxxxxxxx;
> damien.lemoal@xxxxxxxxxxxxxxxxxx; songmuchun@xxxxxxxxxxxxx;
> peterz@xxxxxxxxxxxxx; jpoimboe@xxxxxxxxxx; pbonzini@xxxxxxxxxx;
> chang.seok.bae@xxxxxxxxx; pawan.kumar.gupta@xxxxxxxxxxxxxxx;
> jmattson@xxxxxxxxxx; daniel.sneddon@xxxxxxxxxxxxxxx; Das1, Sandipan
> <Sandipan.Das@xxxxxxx>; tony.luck@xxxxxxxxx; james.morse@xxxxxxx;
> linux-doc@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx;
> bagasdotme@xxxxxxxxx; eranian@xxxxxxxxxx; christophe.leroy@xxxxxxxxxx;
> jarkko@xxxxxxxxxx; adrian.hunter@xxxxxxxxx; quic_jiles@xxxxxxxxxxx;
> peternewman@xxxxxxxxxx
> Subject: Re: [PATCH v9 02/13] x86/resctrl: Add a new resource type
> RDT_RESOURCE_SMBA
> 
> Hi Babu,
> 
> On 12/1/2022 7:36 AM, Babu Moger wrote:
> > Add a new resource type RDT_RESOURCE_SMBA to handle the QoS
> > enforcement policies on the external slow memory.
> >
> 
> I think a snippet like below may help to set reviewer's mind at ease about the
> consequences of values chosen:
> 
> "Mostly initialization of the essentials. Setting fflags to RFTYPE_RES_MB
> configures the SMBA resource to have the same resctrl files as the existing
> MBA resource. The SMBA resource has identical properties to the existing MBA
> resource. These properties will be enumerated in an upcoming change and
> exposed via resctrl because of this flag."

Sure. Will add it.
> 
> > Signed-off-by: Babu Moger <babu.moger@xxxxxxx>
> > ---
> >  arch/x86/kernel/cpu/resctrl/core.c     |   12 ++++++++++++
> >  arch/x86/kernel/cpu/resctrl/internal.h |    1 +
> >  2 files changed, 13 insertions(+)
> >
> > diff --git a/arch/x86/kernel/cpu/resctrl/core.c
> > b/arch/x86/kernel/cpu/resctrl/core.c
> > index c98e52ff5f20..f6af3ac1ef20 100644
> > --- a/arch/x86/kernel/cpu/resctrl/core.c
> > +++ b/arch/x86/kernel/cpu/resctrl/core.c
> > @@ -100,6 +100,18 @@ struct rdt_hw_resource rdt_resources_all[] = {
> >  			.fflags			= RFTYPE_RES_MB,
> >  		},
> >  	},
> > +	[RDT_RESOURCE_SMBA] =
> > +	{
> > +		.r_resctrl = {
> > +			.rid			= RDT_RESOURCE_SMBA,
> > +			.name			= "SMBA",
> > +			.cache_level		= 3,
> > +			.domains		=
> domain_init(RDT_RESOURCE_SMBA),
> > +			.parse_ctrlval		= parse_bw,
> > +			.format_str		= "%d=%*u",
> > +			.fflags			= RFTYPE_RES_MB,
> > +		},
> > +	},
> >  };
> >
> >  /*
> > diff --git a/arch/x86/kernel/cpu/resctrl/internal.h
> > b/arch/x86/kernel/cpu/resctrl/internal.h
> > index 5ebd28e6aa0c..fdbbf66312ec 100644
> > --- a/arch/x86/kernel/cpu/resctrl/internal.h
> > +++ b/arch/x86/kernel/cpu/resctrl/internal.h
> > @@ -409,6 +409,7 @@ enum resctrl_res_level {
> >  	RDT_RESOURCE_L3,
> >  	RDT_RESOURCE_L2,
> >  	RDT_RESOURCE_MBA,
> > +	RDT_RESOURCE_SMBA,
> >
> >  	/* Must be the last */
> >  	RDT_NUM_RESOURCES,
> >
> >
> 
> Reviewed-by: Reinette Chatre <reinette.chatre@xxxxxxxxx>

Thanks
Babu
> 
> Reinette