Re: [PATCH 2/7] x86/resctrl: Add SDCIAE feature in the command line options

Reinette Chatre
2024-09-13T20:45:17Z

Hi Babu,

On 8/16/24 9:16 AM, Babu Moger wrote:
> Add the command line options to enable or disable the new resctrl feature
> L3 Smart Data Cache Injection Allocation Enforcement (SDCIAE).
>
> Signed-off-by: Babu Moger <babu.moger@amd.com>
> ---
> Documentation/admin-guide/kernel-parameters.txt | 2 +-
> arch/x86/kernel/cpu/resctrl/core.c | 2 ++
> 2 files changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> index 09126bb8cc9f..63f17d23b8f4 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -5604,7 +5604,7 @@
> rdt= [HW,X86,RDT]
> Turn on/off individual RDT features. List is:
> cmt, mbmtotal, mbmlocal, l3cat, l3cdp, l2cat, l2cdp,
> - mba, smba, bmec.
> + mba, smba, bmec, sdciae.
> E.g. to turn on cmt and turn off mba use:
> rdt=cmt,!mba
>
> diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c
> index 1930fce9dfe9..c4dfc768ddf5 100644
> --- a/arch/x86/kernel/cpu/resctrl/core.c
> +++ b/arch/x86/kernel/cpu/resctrl/core.c
> @@ -801,6 +801,7 @@ enum {
> RDT_FLAG_MBA,
> RDT_FLAG_SMBA,
> RDT_FLAG_BMEC,
> + RDT_FLAG_SDCIAE,
> };
>
> #define RDT_OPT(idx, n, f) \
> @@ -826,6 +827,7 @@ static struct rdt_options rdt_options[] __initdata = {
> RDT_OPT(RDT_FLAG_MBA, "mba", X86_FEATURE_MBA),
> RDT_OPT(RDT_FLAG_SMBA, "smba", X86_FEATURE_SMBA),
> RDT_OPT(RDT_FLAG_BMEC, "bmec", X86_FEATURE_BMEC),
> + RDT_OPT(RDT_FLAG_SDCIAE, "sdciae", X86_FEATURE_SDCIAE),
> };
> #define NUM_RDT_OPTIONS ARRAY_SIZE(rdt_options)
>

Why is this needed when patch #5 introduces an interface to enable/disable
this feature after mount?

Reinette