[v3] Add support for AMD hardware feedback interface

[PATCH v3 10/14] x86/cpu: Enable SD_ASYM_PACKING for DIE Domain on AMD Processors

Posted by Mario Limonciello 4 months, 3 weeks ago

From: Perry Yuan <perry.yuan@amd.com>

Enable the SD_ASYM_PACKING domain flag for the DIE domain on AMD
heterogeneous processors.
This flag is beneficial for processors with one or more CCDs and
relies on x86_sched_itmt_flags().

Signed-off-by: Perry Yuan <perry.yuan@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
 arch/x86/kernel/smpboot.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 766f092dab80..c01bb75d0375 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -497,8 +497,9 @@ static int x86_cluster_flags(void)
 
 static int x86_die_flags(void)
 {
-	if (cpu_feature_enabled(X86_FEATURE_HYBRID_CPU))
-	       return x86_sched_itmt_flags();
+	if (cpu_feature_enabled(X86_FEATURE_HYBRID_CPU) ||
+	    cpu_feature_enabled(X86_FEATURE_HETERO_CORE_TOPOLOGY))
+		return x86_sched_itmt_flags();
 
 	return 0;
 }
-- 
2.43.0

Re: [PATCH v3 10/14] x86/cpu: Enable SD_ASYM_PACKING for DIE Domain on AMD Processors

Posted by Gautham R. Shenoy 4 months, 3 weeks ago

On Tue, Oct 15, 2024 at 04:36:41PM -0500, Mario Limonciello wrote:
> From: Perry Yuan <perry.yuan@amd.com>
> 
> Enable the SD_ASYM_PACKING domain flag for the DIE domain on AMD

Nit: It is called the PKG domain now instead of the DIE domain.

# grep . /sys/kernel/debug/sched/domains/cpu0/domain*/name
/sys/kernel/debug/sched/domains/cpu0/domain0/name:SMT
/sys/kernel/debug/sched/domains/cpu0/domain1/name:MC
/sys/kernel/debug/sched/domains/cpu0/domain2/name:PKG <----
/sys/kernel/debug/sched/domains/cpu0/domain3/name:NUMA


> heterogeneous processors.
> This flag is beneficial for processors with one or more CCDs and
> relies on x86_sched_itmt_flags().
> 
> Signed-off-by: Perry Yuan <perry.yuan@amd.com>
> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>

Looks good to me otherwise.

Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>

> ---
>  arch/x86/kernel/smpboot.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
> index 766f092dab80..c01bb75d0375 100644
> --- a/arch/x86/kernel/smpboot.c
> +++ b/arch/x86/kernel/smpboot.c
> @@ -497,8 +497,9 @@ static int x86_cluster_flags(void)
>  
>  static int x86_die_flags(void)
>  {
> -	if (cpu_feature_enabled(X86_FEATURE_HYBRID_CPU))
> -	       return x86_sched_itmt_flags();
> +	if (cpu_feature_enabled(X86_FEATURE_HYBRID_CPU) ||
> +	    cpu_feature_enabled(X86_FEATURE_HETERO_CORE_TOPOLOGY))
> +		return x86_sched_itmt_flags();
>  
>  	return 0;
>  }
> -- 
> 2.43.0
>