diff mbox series

[v2,06/17] x86/resctrl: Introduce interface to display number of ABMC counters

Message ID c16cac16c813a203390229d77d5ab37ebc923d95.1705688539.git.babu.moger@amd.com
State New
Headers
Series x86/resctrl : Support AMD Assignable Bandwidth Monitoring Counters (ABMC) |

Commit Message

Moger, Babu Jan. 19, 2024, 6:22 p.m. UTC 
  The ABMC feature provides an option to the user to pin (or assign) the
RMID to the hardware counter and monitor the bandwidth for a longer
duration. There are only a limited number of hardware counters.

Provide the interface to display the number of ABMC counters supported.

Signed-off-by: Babu Moger <babu.moger@amd.com>

---
v2: Changed the field name to mbm_assignable_counters from abmc_counters.
---
 Documentation/arch/x86/resctrl.rst     |  4 ++++
 arch/x86/kernel/cpu/resctrl/monitor.c  |  4 ++++
 arch/x86/kernel/cpu/resctrl/rdtgroup.c | 17 +++++++++++++++++
 3 files changed, 25 insertions(+)

Comments

James Morse Feb. 20, 2024, 6:14 p.m. UTC | #1 
Hi Babu,

On 19/01/2024 18:22, Babu Moger wrote:
> The ABMC feature provides an option to the user to pin (or assign) the
> RMID to the hardware counter and monitor the bandwidth for a longer
> duration. There are only a limited number of hardware counters.
> 
> Provide the interface to display the number of ABMC counters supported.


> diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c
> index a6c336b6de61..fa492ea820f0 100644
> --- a/arch/x86/kernel/cpu/resctrl/monitor.c
> +++ b/arch/x86/kernel/cpu/resctrl/monitor.c
> @@ -823,6 +823,10 @@ int __init rdt_get_mon_l3_config(struct rdt_resource *r)
>  			resctrl_file_fflags_init("mbm_local_bytes_config",
>  						 RFTYPE_MON_INFO | RFTYPE_RES_CACHE);
>  		}
> +

> +		if (rdt_cpu_has(X86_FEATURE_ABMC))

Please put this in a header and calling it something like
resctrl_arch_has_assignable_counters(). These X86 feature definition macros aren't
available on other architectures!


> +			resctrl_file_fflags_init("mbm_assignable_counters",
> +						 RFTYPE_MON_INFO);
>  	}
>  
>  	l3_mon_evt_init(r);
> diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> index 3e233251e7ed..53be5cd1c28e 100644
> --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> @@ -811,6 +811,17 @@ static int rdtgroup_rmid_show(struct kernfs_open_file *of,
>  	return ret;
>  }
>  
> +static int rdtgroup_mbm_assignable_counters_show(struct kernfs_open_file *of,
> +						 struct seq_file *s, void *v)
> +{
> +	struct rdt_resource *r = of->kn->parent->priv;

> +	struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r);

(After the move out to /fs/ the resctrl_to_arch_res() macro is private to the arch code.
 Needing to do this when providing a value to user-space is the indication that the value
 should be in struct rdt_resource instead!)


> +	seq_printf(s, "%d\n", hw_res->mbm_assignable_counters);
> +
> +	return 0;
> +}
> +
>  #ifdef CONFIG_PROC_CPU_RESCTRL
>  
>  /*


Thanks,

James
Moger, Babu Feb. 20, 2024, 9:23 p.m. UTC | #2 
Hi James,

On 2/20/24 12:14, James Morse wrote:
> Hi Babu,
> 
> On 19/01/2024 18:22, Babu Moger wrote:
>> The ABMC feature provides an option to the user to pin (or assign) the
>> RMID to the hardware counter and monitor the bandwidth for a longer
>> duration. There are only a limited number of hardware counters.
>>
>> Provide the interface to display the number of ABMC counters supported.
> 
> 
>> diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c
>> index a6c336b6de61..fa492ea820f0 100644
>> --- a/arch/x86/kernel/cpu/resctrl/monitor.c
>> +++ b/arch/x86/kernel/cpu/resctrl/monitor.c
>> @@ -823,6 +823,10 @@ int __init rdt_get_mon_l3_config(struct rdt_resource *r)
>>  			resctrl_file_fflags_init("mbm_local_bytes_config",
>>  						 RFTYPE_MON_INFO | RFTYPE_RES_CACHE);
>>  		}
>> +
> 
>> +		if (rdt_cpu_has(X86_FEATURE_ABMC))
> 
> Please put this in a header and calling it something like
> resctrl_arch_has_assignable_counters(). These X86 feature definition macros aren't
> available on other architectures!

Sure. Will do.

> 
> 
>> +			resctrl_file_fflags_init("mbm_assignable_counters",
>> +						 RFTYPE_MON_INFO);
>>  	}
>>  
>>  	l3_mon_evt_init(r);
>> diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
>> index 3e233251e7ed..53be5cd1c28e 100644
>> --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
>> +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
>> @@ -811,6 +811,17 @@ static int rdtgroup_rmid_show(struct kernfs_open_file *of,
>>  	return ret;
>>  }
>>  
>> +static int rdtgroup_mbm_assignable_counters_show(struct kernfs_open_file *of,
>> +						 struct seq_file *s, void *v)
>> +{
>> +	struct rdt_resource *r = of->kn->parent->priv;
> 
>> +	struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r);
> 
> (After the move out to /fs/ the resctrl_to_arch_res() macro is private to the arch code.
>  Needing to do this when providing a value to user-space is the indication that the value
>  should be in struct rdt_resource instead!)

Ok. Sure. Will

> 
> 
>> +	seq_printf(s, "%d\n", hw_res->mbm_assignable_counters);
>> +
>> +	return 0;
>> +}
>> +
>>  #ifdef CONFIG_PROC_CPU_RESCTRL
>>  
>>  /*
> 
> 
> Thanks,
> 
> James
diff mbox series

Patch

diff --git a/Documentation/arch/x86/resctrl.rst b/Documentation/arch/x86/resctrl.rst
index ecc6c65bdaca..73eeb50fd0b5 100644
--- a/Documentation/arch/x86/resctrl.rst
+++ b/Documentation/arch/x86/resctrl.rst
@@ -264,6 +264,10 @@  with the following files:
 	    # cat /sys/fs/resctrl/info/L3_MON/mbm_local_bytes_config
 	    0=0x30;1=0x30;3=0x15;4=0x15
 
+"mbm_assignable_counters":
+	Available when ABMC feature is supported. The number of assignable bandwidth
+	monitoring counters available.
+
 "max_threshold_occupancy":
 		Read/write file provides the largest value (in
 		bytes) at which a previously used LLC_occupancy
diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c
index a6c336b6de61..fa492ea820f0 100644
--- a/arch/x86/kernel/cpu/resctrl/monitor.c
+++ b/arch/x86/kernel/cpu/resctrl/monitor.c
@@ -823,6 +823,10 @@  int __init rdt_get_mon_l3_config(struct rdt_resource *r)
 			resctrl_file_fflags_init("mbm_local_bytes_config",
 						 RFTYPE_MON_INFO | RFTYPE_RES_CACHE);
 		}
+
+		if (rdt_cpu_has(X86_FEATURE_ABMC))
+			resctrl_file_fflags_init("mbm_assignable_counters",
+						 RFTYPE_MON_INFO);
 	}
 
 	l3_mon_evt_init(r);
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index 3e233251e7ed..53be5cd1c28e 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -811,6 +811,17 @@  static int rdtgroup_rmid_show(struct kernfs_open_file *of,
 	return ret;
 }
 
+static int rdtgroup_mbm_assignable_counters_show(struct kernfs_open_file *of,
+						 struct seq_file *s, void *v)
+{
+	struct rdt_resource *r = of->kn->parent->priv;
+	struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r);
+
+	seq_printf(s, "%d\n", hw_res->mbm_assignable_counters);
+
+	return 0;
+}
+
 #ifdef CONFIG_PROC_CPU_RESCTRL
 
 /*
@@ -1861,6 +1872,12 @@  static struct rftype res_common_files[] = {
 		.seq_show	= mbm_local_bytes_config_show,
 		.write		= mbm_local_bytes_config_write,
 	},
+	{
+		.name		= "mbm_assignable_counters",
+		.mode		= 0444,
+		.kf_ops		= &rdtgroup_kf_single_ops,
+		.seq_show	= rdtgroup_mbm_assignable_counters_show,
+	},
 	{
 		.name		= "cpus",
 		.mode		= 0644,