[v2] x86/resctrl : Support L3 Smart Data Cache Injection Allocation Enforcement (SDCIAE)

[PATCH v2 3/7] x86/resctrl: Detect Smart Data Cache Injection Allocation Enforcement

Posted by Babu Moger 12 months ago

Introduce io_alloc_capable in struct resctrl_cache to detect SDCIAE
(L3 Smart Data Cache Injection Allocation Enforcement) feature.

Signed-off-by: Babu Moger <babu.moger@amd.com>
---
v2: Changed sdciae_capable to io_alloc_capable to make it generic feature.
    Also moved the io_alloc_capable in struct resctrl_cache.
---
 arch/x86/kernel/cpu/resctrl/core.c | 7 +++++++
 include/linux/resctrl.h            | 4 ++++
 2 files changed, 11 insertions(+)

diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c
index c2450cd52511..39e110033d96 100644
--- a/arch/x86/kernel/cpu/resctrl/core.c
+++ b/arch/x86/kernel/cpu/resctrl/core.c
@@ -306,6 +306,11 @@ static void rdt_get_cdp_config(int level)
 	rdt_resources_all[level].r_resctrl.cdp_capable = true;
 }
 
+static void rdt_get_sdciae_alloc_cfg(struct rdt_resource *r)
+{
+	r->cache.io_alloc_capable = true;
+}
+
 static void rdt_get_cdp_l3_config(void)
 {
 	rdt_get_cdp_config(RDT_RESOURCE_L3);
@@ -931,6 +936,8 @@ static __init bool get_rdt_alloc_resources(void)
 		rdt_get_cache_alloc_cfg(1, r);
 		if (rdt_cpu_has(X86_FEATURE_CDP_L3))
 			rdt_get_cdp_l3_config();
+		if (rdt_cpu_has(X86_FEATURE_SDCIAE))
+			rdt_get_sdciae_alloc_cfg(r);
 		ret = true;
 	}
 	if (rdt_cpu_has(X86_FEATURE_CAT_L2)) {
diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h
index d94abba1c716..5837acff7442 100644
--- a/include/linux/resctrl.h
+++ b/include/linux/resctrl.h
@@ -129,6 +129,8 @@ struct rdt_mon_domain {
  * @arch_has_sparse_bitmasks:	True if a bitmask like f00f is valid.
  * @arch_has_per_cpu_cfg:	True if QOS_CFG register for this cache
  *				level has CPU scope.
+ * @io_alloc_capable:	Smart Data Cache Injection Allocation Enforcement
+ *			capable (SDCIAE).
  */
 struct resctrl_cache {
 	unsigned int	cbm_len;
@@ -136,6 +138,7 @@ struct resctrl_cache {
 	unsigned int	shareable_bits;
 	bool		arch_has_sparse_bitmasks;
 	bool		arch_has_per_cpu_cfg;
+	bool		io_alloc_capable;
 };
 
 /**
@@ -202,6 +205,7 @@ enum resctrl_scope {
  * @evt_list:		List of monitoring events
  * @fflags:		flags to choose base and info files
  * @cdp_capable:	Is the CDP feature available on this resource
+ * @sdciae_capable:	Is SDCIAE feature available on this resource
  */
 struct rdt_resource {
 	int			rid;
-- 
2.34.1

Re: [PATCH v2 3/7] x86/resctrl: Detect Smart Data Cache Injection Allocation Enforcement

Posted by Reinette Chatre 11 months, 4 weeks ago

Hi Babu,

On 12/18/24 1:37 PM, Babu Moger wrote:
> Introduce io_alloc_capable in struct resctrl_cache to detect SDCIAE
> (L3 Smart Data Cache Injection Allocation Enforcement) feature.

Please distinguish clearly between the resctrl feature ("io_alloc_capable")
and the architecture specific feature (SDCIAE) that backs it. This is similar
to what you have done for ABMC and makes the work much easier to understand.
When the resctrl and arch feature is used interchangeably it becomes confusing.

> 
> Signed-off-by: Babu Moger <babu.moger@amd.com>
> ---
> v2: Changed sdciae_capable to io_alloc_capable to make it generic feature.
>     Also moved the io_alloc_capable in struct resctrl_cache.
> ---
>  arch/x86/kernel/cpu/resctrl/core.c | 7 +++++++
>  include/linux/resctrl.h            | 4 ++++
>  2 files changed, 11 insertions(+)
> 
> diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c
> index c2450cd52511..39e110033d96 100644
> --- a/arch/x86/kernel/cpu/resctrl/core.c
> +++ b/arch/x86/kernel/cpu/resctrl/core.c
> @@ -306,6 +306,11 @@ static void rdt_get_cdp_config(int level)
>  	rdt_resources_all[level].r_resctrl.cdp_capable = true;
>  }
>  
> +static void rdt_get_sdciae_alloc_cfg(struct rdt_resource *r)
> +{
> +	r->cache.io_alloc_capable = true;
> +}

rdt_get_sdciae_alloc_cfg() looks like one that should have "set" in its name, not "get".
This also does not seem architecture specific so "sdciae" should not be in the name.
rdt_set_io_alloc_capable()?

> +
>  static void rdt_get_cdp_l3_config(void)
>  {
>  	rdt_get_cdp_config(RDT_RESOURCE_L3);
> @@ -931,6 +936,8 @@ static __init bool get_rdt_alloc_resources(void)
>  		rdt_get_cache_alloc_cfg(1, r);
>  		if (rdt_cpu_has(X86_FEATURE_CDP_L3))
>  			rdt_get_cdp_l3_config();
> +		if (rdt_cpu_has(X86_FEATURE_SDCIAE))
> +			rdt_get_sdciae_alloc_cfg(r);
>  		ret = true;
>  	}
>  	if (rdt_cpu_has(X86_FEATURE_CAT_L2)) {
> diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h
> index d94abba1c716..5837acff7442 100644
> --- a/include/linux/resctrl.h
> +++ b/include/linux/resctrl.h
> @@ -129,6 +129,8 @@ struct rdt_mon_domain {
>   * @arch_has_sparse_bitmasks:	True if a bitmask like f00f is valid.
>   * @arch_has_per_cpu_cfg:	True if QOS_CFG register for this cache
>   *				level has CPU scope.
> + * @io_alloc_capable:	Smart Data Cache Injection Allocation Enforcement
> + *			capable (SDCIAE).

Please remove arch specific text here. For example,
"True if portion of the L3 cache can be allocated for I/O traffic."

>   */
>  struct resctrl_cache {
>  	unsigned int	cbm_len;
> @@ -136,6 +138,7 @@ struct resctrl_cache {
>  	unsigned int	shareable_bits;
>  	bool		arch_has_sparse_bitmasks;
>  	bool		arch_has_per_cpu_cfg;
> +	bool		io_alloc_capable;
>  };
>  
>  /**
> @@ -202,6 +205,7 @@ enum resctrl_scope {
>   * @evt_list:		List of monitoring events
>   * @fflags:		flags to choose base and info files
>   * @cdp_capable:	Is the CDP feature available on this resource
> + * @sdciae_capable:	Is SDCIAE feature available on this resource
>   */
>  struct rdt_resource {
>  	int			rid;

Leftover from previous version?

Reinette

Re: [PATCH v2 3/7] x86/resctrl: Detect Smart Data Cache Injection Allocation Enforcement

Posted by Moger, Babu 10 months, 4 weeks ago

Hi Reinette,

Sorry.. Was on a vacation.  Addressing the comments now.

On 12/23/24 15:13, Reinette Chatre wrote:
> Hi Babu,
> 
> On 12/18/24 1:37 PM, Babu Moger wrote:
>> Introduce io_alloc_capable in struct resctrl_cache to detect SDCIAE
>> (L3 Smart Data Cache Injection Allocation Enforcement) feature.
> 
> Please distinguish clearly between the resctrl feature ("io_alloc_capable")
> and the architecture specific feature (SDCIAE) that backs it. This is similar
> to what you have done for ABMC and makes the work much easier to understand.
> When the resctrl and arch feature is used interchangeably it becomes confusing.

Sure. Will rewrite the commit text.

> 
>>
>> Signed-off-by: Babu Moger <babu.moger@amd.com>
>> ---
>> v2: Changed sdciae_capable to io_alloc_capable to make it generic feature.
>>     Also moved the io_alloc_capable in struct resctrl_cache.
>> ---
>>  arch/x86/kernel/cpu/resctrl/core.c | 7 +++++++
>>  include/linux/resctrl.h            | 4 ++++
>>  2 files changed, 11 insertions(+)
>>
>> diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c
>> index c2450cd52511..39e110033d96 100644
>> --- a/arch/x86/kernel/cpu/resctrl/core.c
>> +++ b/arch/x86/kernel/cpu/resctrl/core.c
>> @@ -306,6 +306,11 @@ static void rdt_get_cdp_config(int level)
>>  	rdt_resources_all[level].r_resctrl.cdp_capable = true;
>>  }
>>  
>> +static void rdt_get_sdciae_alloc_cfg(struct rdt_resource *r)
>> +{
>> +	r->cache.io_alloc_capable = true;
>> +}
> 
> rdt_get_sdciae_alloc_cfg() looks like one that should have "set" in its name, not "get".
> This also does not seem architecture specific so "sdciae" should not be in the name.
> rdt_set_io_alloc_capable()?

Sure.

> 
>> +
>>  static void rdt_get_cdp_l3_config(void)
>>  {
>>  	rdt_get_cdp_config(RDT_RESOURCE_L3);
>> @@ -931,6 +936,8 @@ static __init bool get_rdt_alloc_resources(void)
>>  		rdt_get_cache_alloc_cfg(1, r);
>>  		if (rdt_cpu_has(X86_FEATURE_CDP_L3))
>>  			rdt_get_cdp_l3_config();
>> +		if (rdt_cpu_has(X86_FEATURE_SDCIAE))
>> +			rdt_get_sdciae_alloc_cfg(r);
>>  		ret = true;
>>  	}
>>  	if (rdt_cpu_has(X86_FEATURE_CAT_L2)) {
>> diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h
>> index d94abba1c716..5837acff7442 100644
>> --- a/include/linux/resctrl.h
>> +++ b/include/linux/resctrl.h
>> @@ -129,6 +129,8 @@ struct rdt_mon_domain {
>>   * @arch_has_sparse_bitmasks:	True if a bitmask like f00f is valid.
>>   * @arch_has_per_cpu_cfg:	True if QOS_CFG register for this cache
>>   *				level has CPU scope.
>> + * @io_alloc_capable:	Smart Data Cache Injection Allocation Enforcement
>> + *			capable (SDCIAE).
> 
> Please remove arch specific text here. For example,
> "True if portion of the L3 cache can be allocated for I/O traffic."

Sure.
> 
>>   */
>>  struct resctrl_cache {
>>  	unsigned int	cbm_len;
>> @@ -136,6 +138,7 @@ struct resctrl_cache {
>>  	unsigned int	shareable_bits;
>>  	bool		arch_has_sparse_bitmasks;
>>  	bool		arch_has_per_cpu_cfg;
>> +	bool		io_alloc_capable;
>>  };
>>  
>>  /**
>> @@ -202,6 +205,7 @@ enum resctrl_scope {
>>   * @evt_list:		List of monitoring events
>>   * @fflags:		flags to choose base and info files
>>   * @cdp_capable:	Is the CDP feature available on this resource
>> + * @sdciae_capable:	Is SDCIAE feature available on this resource
>>   */
>>  struct rdt_resource {
>>  	int			rid;
> 
> Leftover from previous version?

Yes. Will remove it.

Thanks
Babu Moger

[PATCH v2 1/7] x86/cpufeatures: Add support for L3 Smart Data Cache Injection Allocation Enforcement
[PATCH v2 2/7] x86/resctrl: Add SDCIAE feature in the command line options
[PATCH v2 3/7] x86/resctrl: Detect Smart Data Cache Injection Allocation Enforcement
[PATCH v2 4/7] x86/resctrl: Implement "io_alloc" enable/disable handlers
[PATCH v2 5/7] x86/resctrl: Add interface to enable/disable io_alloc feature
[PATCH v2 6/7] x86/resctrl: Introduce interface to display io_alloc CBMs
[PATCH v2 7/7] x86/resctrl: Introduce interface to modify io_alloc Capacity Bit Masks