[PATCH v6 12/12] Documentation/x86: Update resctrl_ui.rst for new features

Babu Moger posted 12 patches 3 years, 5 months ago
There is a newer version of this series
[PATCH v6 12/12] Documentation/x86: Update resctrl_ui.rst for new features
Posted by Babu Moger 3 years, 5 months ago
Update the documentation for the new features:
1. Slow Memory Bandwidth allocation (SMBA).
   With this feature, the QOS  enforcement policies can be applied
   to the external slow memory connected to the host. QOS enforcement
   is accomplished by assigning a Class Of Service (COS) to a processor
   and specifying allocations or limits for that COS for each resource
   to be allocated.

2. Bandwidth Monitoring Event Configuration (BMEC).
   The bandwidth monitoring events mbm_total_bytes and mbm_local_bytes
   are set to count all the total and local reads/writes respectively.
   With the introduction of slow memory, the two counters are not
   enough to count all the different types of memory events. With the
   feature BMEC, the users have the option to configure mbm_total_bytes
   and mbm_local_bytes to count the specific type of events.

Also add configuration instructions with examples.

Signed-off-by: Babu Moger <babu.moger@amd.com>
---
 Documentation/x86/resctrl.rst |  136 ++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 134 insertions(+), 2 deletions(-)

diff --git a/Documentation/x86/resctrl.rst b/Documentation/x86/resctrl.rst
index 71a531061e4e..e2a59249d183 100644
--- a/Documentation/x86/resctrl.rst
+++ b/Documentation/x86/resctrl.rst
@@ -17,14 +17,16 @@ AMD refers to this feature as AMD Platform Quality of Service(AMD QoS).
 This feature is enabled by the CONFIG_X86_CPU_RESCTRL and the x86 /proc/cpuinfo
 flag bits:
 
-=============================================	================================
+===============================================	================================
 RDT (Resource Director Technology) Allocation	"rdt_a"
 CAT (Cache Allocation Technology)		"cat_l3", "cat_l2"
 CDP (Code and Data Prioritization)		"cdp_l3", "cdp_l2"
 CQM (Cache QoS Monitoring)			"cqm_llc", "cqm_occup_llc"
 MBM (Memory Bandwidth Monitoring)		"cqm_mbm_total", "cqm_mbm_local"
 MBA (Memory Bandwidth Allocation)		"mba"
-=============================================	================================
+SMBA (Slow Memory Bandwidth Allocation)         "smba"
+BMEC (Bandwidth Monitoring Event Configuration) "bmec"
+===============================================	================================
 
 To use the feature mount the file system::
 
@@ -161,6 +163,79 @@ with the following files:
 "mon_features":
 		Lists the monitoring events if
 		monitoring is enabled for the resource.
+                Example::
+
+                   # cat /sys/fs/resctrl/info/L3_MON/mon_features
+                   llc_occupancy
+                   mbm_total_bytes
+                   mbm_local_bytes
+
+                If the system supports Bandwidth Monitoring Event
+                Configuration (BMEC), then the bandwidth events will
+                be configurable. The output will be::
+
+                   # cat /sys/fs/resctrl/info/L3_MON/mon_features
+                   llc_occupancy
+                   mbm_total_bytes
+                   mbm_total_config
+                   mbm_local_bytes
+                   mbm_local_config
+
+"mbm_total_config", "mbm_local_config":
+        These files contain the current event configuration for the events
+        mbm_total_bytes and mbm_local_bytes, respectively, when the
+        Bandwidth Monitoring Event Configuration (BMEC) feature is supported.
+        The event configuration settings are domain specific and will affect
+        all the CPUs in the domain.
+
+        Following are the types of events supported:
+
+        ====    ========================================================
+        Bits    Description
+        ====    ========================================================
+        6       Dirty Victims from the QOS domain to all types of memory
+        5       Reads to slow memory in the non-local NUMA domain
+        4       Reads to slow memory in the local NUMA domain
+        3       Non-temporal writes to non-local NUMA domain
+        2       Non-temporal writes to local NUMA domain
+        1       Reads to memory in the non-local NUMA domain
+        0       Reads to memory in the local NUMA domain
+        ====    ========================================================
+
+        By default, the mbm_total_bytes configuration is set to 0x7f to count
+        all the event types and the mbm_local_bytes configuration is set to
+        0x15 to count all the local memory events.
+
+        Examples:
+
+        * To view the current configuration::
+          ::
+
+            # cat /sys/fs/resctrl/info/L3_MON/mbm_total_config
+            0=0x7f;1=0x7f;2=0x7f;3=0x7f
+
+            # cat /sys/fs/resctrl/info/L3_MON/mbm_local_config
+            0=0x15;1=0x15;3=0x15;4=0x15
+
+        * To change the mbm_total_bytes to count only reads on domain 0.
+          To achieve this, the bits 0, 1, 4 and 5 needs to be set which is
+          110011b (in hex 0x33).
+          ::
+
+            # echo  "0=0x33" > /sys/fs/resctrl/info/L3_MON/mbm_total_config
+
+            # cat /sys/fs/resctrl/info/L3_MON/mbm_total_config
+            0=0x33;1=0x7f;2=0x7f;3=0x7f
+
+        * To change the mbm_local_bytes to count all the slow memory reads
+          on domain 1. To achieve this, the bits 4 and 5 needs to be set
+          which is 110000b (in hex 0x30).
+          ::
+
+            # echo  "1=0x30" > /sys/fs/resctrl/info/L3_MON/mbm_local_config
+
+            # cat /sys/fs/resctrl/info/L3_MON/mbm_local_config
+            0=0x15;1=0x30;3=0x15;4=0x15
 
 "max_threshold_occupancy":
 		Read/write file provides the largest value (in
@@ -464,6 +539,25 @@ Memory bandwidth domain is L3 cache.
 
 	MB:<cache_id0>=bw_MBps0;<cache_id1>=bw_MBps1;...
 
+Slow Memory bandwidth Allocation (SMBA)
+-------------------------------------------------
+AMD hardware can support slow Memory bandwidth Allocation feature.
+Currently, CXL.memory is the only supported "slow" memory device.
+With the support of SMBA feature the hardware enables bandwidth
+allocation on the slow memory devices. If there are multiple slow
+memory devices in the system, then the throttling logic groups all
+the slow sources together and applies the limit on them as a whole.
+
+The presence of the SMBA feature(with CXL.memory) is independent
+of whether slow memory device is actually present in the system.
+If there is no slow memory in the system, then setting a SMBA limit
+will have no impact on the performance of the system.
+
+Slow Memory bandwidth domain is L3 cache.
+::
+
+	SMBA:<cache_id0>=bandwidth0;<cache_id1>=bandwidth1;...
+
 Reading/writing the schemata file
 ---------------------------------
 Reading the schemata file will show the state of all resources
@@ -479,6 +573,44 @@ which you wish to change.  E.g.
   L3DATA:0=fffff;1=fffff;2=3c0;3=fffff
   L3CODE:0=fffff;1=fffff;2=fffff;3=fffff
 
+Reading/writing the schemata file (on AMD systems)
+--------------------------------------------------
+Reading the schemata file will show the state of all resources
+on all domains. When writing the memory bandwidth allocation you
+only need to specify those values in an absolute number expressed
+in 1/8 GB/s increments. To allocate bandwidth limit of 2GB, you
+need to specify the value 16 (16 * 1/8 = 2). For example:
+::
+
+  # cat schemata
+    MB:0=2048;1=2048;2=2048;3=2048
+    L3:0=ffff;1=ffff;2=ffff;3=ffff
+
+  # echo "MB:1=16" > schemata
+  # cat schemata
+    MB:0=2048;1=  16;2=2048;3=2048
+    L3:0=ffff;1=ffff;2=ffff;3=ffff
+
+Reading/writing the schemata file (on AMD systems) with SMBA feature
+-------------------------------------------------------------------
+Reading the schemata file will show the state of all resources
+on all domains. When writing the memory bandwidth allocation you
+only need to specify those values in an absolute number expressed
+in 1/8 GB/s increments. To allocate bandwidth limit of 8GB, you
+need to specify the value 64 (64 * 1/8 = 8).  E.g.
+::
+
+  # cat schemata
+    SMBA:0=2048;1=2048;2=2048;3=2048
+      MB:0=2048;1=2048;2=2048;3=2048
+      L3:0=ffff;1=ffff;2=ffff;3=ffff
+
+  # echo "SMBA:1=64" > schemata
+  # cat schemata
+    SMBA:0=2048;1=  64;2=2048;3=2048
+      MB:0=2048;1=2048;2=2048;3=2048
+      L3:0=ffff;1=ffff;2=ffff;3=ffff
+
 Cache Pseudo-Locking
 ====================
 CAT enables a user to specify the amount of cache space that an

Re: [PATCH v6 12/12] Documentation/x86: Update resctrl_ui.rst for new features
Posted by Bagas Sanjaya 3 years, 5 months ago
On Mon, Oct 10, 2022 at 03:30:40PM -0500, Babu Moger wrote:
> diff --git a/Documentation/x86/resctrl.rst b/Documentation/x86/resctrl.rst
> index 71a531061e4e..e2a59249d183 100644
> --- a/Documentation/x86/resctrl.rst
> +++ b/Documentation/x86/resctrl.rst
> @@ -17,14 +17,16 @@ AMD refers to this feature as AMD Platform Quality of Service(AMD QoS).
>  This feature is enabled by the CONFIG_X86_CPU_RESCTRL and the x86 /proc/cpuinfo
>  flag bits:
>  
> -=============================================	================================
> +===============================================	================================
>  RDT (Resource Director Technology) Allocation	"rdt_a"
>  CAT (Cache Allocation Technology)		"cat_l3", "cat_l2"
>  CDP (Code and Data Prioritization)		"cdp_l3", "cdp_l2"
>  CQM (Cache QoS Monitoring)			"cqm_llc", "cqm_occup_llc"
>  MBM (Memory Bandwidth Monitoring)		"cqm_mbm_total", "cqm_mbm_local"
>  MBA (Memory Bandwidth Allocation)		"mba"
> -=============================================	================================
> +SMBA (Slow Memory Bandwidth Allocation)         "smba"
> +BMEC (Bandwidth Monitoring Event Configuration) "bmec"
> +===============================================	================================
>  
>  To use the feature mount the file system::
>  
> @@ -161,6 +163,79 @@ with the following files:
>  "mon_features":
>  		Lists the monitoring events if
>  		monitoring is enabled for the resource.
> +                Example::
> +
> +                   # cat /sys/fs/resctrl/info/L3_MON/mon_features
> +                   llc_occupancy
> +                   mbm_total_bytes
> +                   mbm_local_bytes
> +
> +                If the system supports Bandwidth Monitoring Event
> +                Configuration (BMEC), then the bandwidth events will
> +                be configurable. The output will be::
> +
> +                   # cat /sys/fs/resctrl/info/L3_MON/mon_features
> +                   llc_occupancy
> +                   mbm_total_bytes
> +                   mbm_total_config
> +                   mbm_local_bytes
> +                   mbm_local_config
> +
> +"mbm_total_config", "mbm_local_config":
> +        These files contain the current event configuration for the events
> +        mbm_total_bytes and mbm_local_bytes, respectively, when the
> +        Bandwidth Monitoring Event Configuration (BMEC) feature is supported.
> +        The event configuration settings are domain specific and will affect
> +        all the CPUs in the domain.
> +
> +        Following are the types of events supported:
> +
> +        ====    ========================================================
> +        Bits    Description
> +        ====    ========================================================
> +        6       Dirty Victims from the QOS domain to all types of memory
> +        5       Reads to slow memory in the non-local NUMA domain
> +        4       Reads to slow memory in the local NUMA domain
> +        3       Non-temporal writes to non-local NUMA domain
> +        2       Non-temporal writes to local NUMA domain
> +        1       Reads to memory in the non-local NUMA domain
> +        0       Reads to memory in the local NUMA domain
> +        ====    ========================================================
> +
> +        By default, the mbm_total_bytes configuration is set to 0x7f to count
> +        all the event types and the mbm_local_bytes configuration is set to
> +        0x15 to count all the local memory events.
> +
> +        Examples:
> +
> +        * To view the current configuration::
> +          ::
> +
> +            # cat /sys/fs/resctrl/info/L3_MON/mbm_total_config
> +            0=0x7f;1=0x7f;2=0x7f;3=0x7f
> +
> +            # cat /sys/fs/resctrl/info/L3_MON/mbm_local_config
> +            0=0x15;1=0x15;3=0x15;4=0x15
> +
> +        * To change the mbm_total_bytes to count only reads on domain 0.
> +          To achieve this, the bits 0, 1, 4 and 5 needs to be set which is
> +          110011b (in hex 0x33).
> +          ::
> +
> +            # echo  "0=0x33" > /sys/fs/resctrl/info/L3_MON/mbm_total_config
> +
> +            # cat /sys/fs/resctrl/info/L3_MON/mbm_total_config
> +            0=0x33;1=0x7f;2=0x7f;3=0x7f
> +
> +        * To change the mbm_local_bytes to count all the slow memory reads
> +          on domain 1. To achieve this, the bits 4 and 5 needs to be set
> +          which is 110000b (in hex 0x30).
> +          ::
> +
> +            # echo  "1=0x30" > /sys/fs/resctrl/info/L3_MON/mbm_local_config
> +
> +            # cat /sys/fs/resctrl/info/L3_MON/mbm_local_config
> +            0=0x15;1=0x30;3=0x15;4=0x15
>  
>  "max_threshold_occupancy":
>  		Read/write file provides the largest value (in
> @@ -464,6 +539,25 @@ Memory bandwidth domain is L3 cache.
>  
>  	MB:<cache_id0>=bw_MBps0;<cache_id1>=bw_MBps1;...
>  
> +Slow Memory bandwidth Allocation (SMBA)
> +-------------------------------------------------
> +AMD hardware can support slow Memory bandwidth Allocation feature.
> +Currently, CXL.memory is the only supported "slow" memory device.
> +With the support of SMBA feature the hardware enables bandwidth
> +allocation on the slow memory devices. If there are multiple slow
> +memory devices in the system, then the throttling logic groups all
> +the slow sources together and applies the limit on them as a whole.
> +
> +The presence of the SMBA feature(with CXL.memory) is independent
> +of whether slow memory device is actually present in the system.
> +If there is no slow memory in the system, then setting a SMBA limit
> +will have no impact on the performance of the system.
> +
> +Slow Memory bandwidth domain is L3 cache.
> +::
> +
> +	SMBA:<cache_id0>=bandwidth0;<cache_id1>=bandwidth1;...
> +
>  Reading/writing the schemata file
>  ---------------------------------
>  Reading the schemata file will show the state of all resources
> @@ -479,6 +573,44 @@ which you wish to change.  E.g.
>    L3DATA:0=fffff;1=fffff;2=3c0;3=fffff
>    L3CODE:0=fffff;1=fffff;2=fffff;3=fffff
>  
> +Reading/writing the schemata file (on AMD systems)
> +--------------------------------------------------
> +Reading the schemata file will show the state of all resources
> +on all domains. When writing the memory bandwidth allocation you
> +only need to specify those values in an absolute number expressed
> +in 1/8 GB/s increments. To allocate bandwidth limit of 2GB, you
> +need to specify the value 16 (16 * 1/8 = 2). For example:
> +::
> +
> +  # cat schemata
> +    MB:0=2048;1=2048;2=2048;3=2048
> +    L3:0=ffff;1=ffff;2=ffff;3=ffff
> +
> +  # echo "MB:1=16" > schemata
> +  # cat schemata
> +    MB:0=2048;1=  16;2=2048;3=2048
> +    L3:0=ffff;1=ffff;2=ffff;3=ffff
> +
> +Reading/writing the schemata file (on AMD systems) with SMBA feature
> +-------------------------------------------------------------------

The heading above produces htmldocs warnings:

Documentation/x86/resctrl.rst:595: WARNING: Title underline too short.

Reading/writing the schemata file (on AMD systems) with SMBA feature
-------------------------------------------------------------------
Documentation/x86/resctrl.rst:595: WARNING: Title underline too short.

Reading/writing the schemata file (on AMD systems) with SMBA feature
-------------------------------------------------------------------

I have applied the fixup:

---- >8 ----

diff --git a/Documentation/x86/resctrl.rst b/Documentation/x86/resctrl.rst
index e2a59249d18322..145916828f2bae 100644
--- a/Documentation/x86/resctrl.rst
+++ b/Documentation/x86/resctrl.rst
@@ -592,7 +592,7 @@ need to specify the value 16 (16 * 1/8 = 2). For example:
     L3:0=ffff;1=ffff;2=ffff;3=ffff
 
 Reading/writing the schemata file (on AMD systems) with SMBA feature
--------------------------------------------------------------------
+--------------------------------------------------------------------
 Reading the schemata file will show the state of all resources
 on all domains. When writing the memory bandwidth allocation you
 only need to specify those values in an absolute number expressed

> +Reading the schemata file will show the state of all resources
> +on all domains. When writing the memory bandwidth allocation you
> +only need to specify those values in an absolute number expressed
> +in 1/8 GB/s increments. To allocate bandwidth limit of 8GB, you
> +need to specify the value 64 (64 * 1/8 = 8).  E.g.
> +::
> +
> +  # cat schemata
> +    SMBA:0=2048;1=2048;2=2048;3=2048
> +      MB:0=2048;1=2048;2=2048;3=2048
> +      L3:0=ffff;1=ffff;2=ffff;3=ffff
> +
> +  # echo "SMBA:1=64" > schemata
> +  # cat schemata
> +    SMBA:0=2048;1=  64;2=2048;3=2048
> +      MB:0=2048;1=2048;2=2048;3=2048
> +      L3:0=ffff;1=ffff;2=ffff;3=ffff
> +
>  Cache Pseudo-Locking
>  ====================
>  CAT enables a user to specify the amount of cache space that an
> 
> 

The rest of prose can be improved:

---- >8 ----

diff --git a/Documentation/x86/resctrl.rst b/Documentation/x86/resctrl.rst
index 145916828f2bae..92b2c4e03a4a26 100644
--- a/Documentation/x86/resctrl.rst
+++ b/Documentation/x86/resctrl.rst
@@ -217,9 +217,9 @@ with the following files:
             # cat /sys/fs/resctrl/info/L3_MON/mbm_local_config
             0=0x15;1=0x15;3=0x15;4=0x15
 
-        * To change the mbm_total_bytes to count only reads on domain 0.
-          To achieve this, the bits 0, 1, 4 and 5 needs to be set which is
-          110011b (in hex 0x33).
+        * To change the mbm_total_bytes to count only reads on domain 0
+          (the bits 0, 1, 4 and 5 needs to be set, which means 110011b
+          {in hex 0x33}):
           ::
 
             # echo  "0=0x33" > /sys/fs/resctrl/info/L3_MON/mbm_total_config
@@ -228,8 +228,8 @@ with the following files:
             0=0x33;1=0x7f;2=0x7f;3=0x7f
 
         * To change the mbm_local_bytes to count all the slow memory reads
-          on domain 1. To achieve this, the bits 4 and 5 needs to be set
-          which is 110000b (in hex 0x30).
+          on domain 1 (the bits 4 and 5 needs to be set, which means 110000b
+          {in hex 0x30}):
           ::
 
             # echo  "1=0x30" > /sys/fs/resctrl/info/L3_MON/mbm_local_config
@@ -540,20 +540,21 @@ Memory bandwidth domain is L3 cache.
 	MB:<cache_id0>=bw_MBps0;<cache_id1>=bw_MBps1;...
 
 Slow Memory bandwidth Allocation (SMBA)
--------------------------------------------------
-AMD hardware can support slow Memory bandwidth Allocation feature.
+---------------------------------------
+AMD hardwares support Slow Memory bandwidth Allocation (SMBA) feature.
 Currently, CXL.memory is the only supported "slow" memory device.
-With the support of SMBA feature the hardware enables bandwidth
-allocation on the slow memory devices. If there are multiple slow
-memory devices in the system, then the throttling logic groups all
-the slow sources together and applies the limit on them as a whole.
+With the support of SMBA, the hardware enables bandwidth allocation
+on the slow memory devices. If there are multiple such devices in the
+system, the throttling logic groups all the slow sources together
+and applies the limit on them as a whole.
 
-The presence of the SMBA feature(with CXL.memory) is independent
-of whether slow memory device is actually present in the system.
-If there is no slow memory in the system, then setting a SMBA limit
-will have no impact on the performance of the system.
+The presence of SMBA (with CXL.memory) is independent of slow memory
+devices presence. If there is no such devices on the system, then
+setting the configuring SMBA will have no impact on the performance
+of the system.
 
-Slow Memory bandwidth domain is L3 cache.
+The bandwidth domain for slow memory is L3 cache. Its schemata file
+is formatted as:
 ::
 
 	SMBA:<cache_id0>=bandwidth0;<cache_id1>=bandwidth1;...
@@ -575,11 +576,13 @@ which you wish to change.  E.g.
 
 Reading/writing the schemata file (on AMD systems)
 --------------------------------------------------
-Reading the schemata file will show the state of all resources
-on all domains. When writing the memory bandwidth allocation you
-only need to specify those values in an absolute number expressed
-in 1/8 GB/s increments. To allocate bandwidth limit of 2GB, you
-need to specify the value 16 (16 * 1/8 = 2). For example:
+Reading the schemata file will show the current bandwidth limit on all
+domains. The allocated resources are in multiples of one eighth GB/s.
+When writing to the file, you need to specify what cache id you wish to
+configure the bandwidth limit.
+
+For example, to allocate 2GB/s limit on the first cache id:
+
 ::
 
   # cat schemata
@@ -593,11 +596,11 @@ need to specify the value 16 (16 * 1/8 = 2). For example:
 
 Reading/writing the schemata file (on AMD systems) with SMBA feature
 --------------------------------------------------------------------
-Reading the schemata file will show the state of all resources
-on all domains. When writing the memory bandwidth allocation you
-only need to specify those values in an absolute number expressed
-in 1/8 GB/s increments. To allocate bandwidth limit of 8GB, you
-need to specify the value 64 (64 * 1/8 = 8).  E.g.
+Reading and writing the schemata file is the same as without SMBA in
+above section.
+
+For example, to allocate 8GB/s limit on the first cache id:
+
 ::
 
   # cat schemata

Thanks.

-- 
An old man doll... just what I always wanted! - Clara
Re: [PATCH v6 12/12] Documentation/x86: Update resctrl_ui.rst for new features
Posted by Moger, Babu 3 years, 5 months ago
Hi Sanjaya,

On 10/11/22 04:06, Bagas Sanjaya wrote:
> On Mon, Oct 10, 2022 at 03:30:40PM -0500, Babu Moger wrote:
>> diff --git a/Documentation/x86/resctrl.rst b/Documentation/x86/resctrl.rst
>> index 71a531061e4e..e2a59249d183 100644
>> --- a/Documentation/x86/resctrl.rst
>> +++ b/Documentation/x86/resctrl.rst
>> @@ -17,14 +17,16 @@ AMD refers to this feature as AMD Platform Quality of Service(AMD QoS).
>>  This feature is enabled by the CONFIG_X86_CPU_RESCTRL and the x86 /proc/cpuinfo
>>  flag bits:
>>  
>> -=============================================	================================
>> +===============================================	================================
>>  RDT (Resource Director Technology) Allocation	"rdt_a"
>>  CAT (Cache Allocation Technology)		"cat_l3", "cat_l2"
>>  CDP (Code and Data Prioritization)		"cdp_l3", "cdp_l2"
>>  CQM (Cache QoS Monitoring)			"cqm_llc", "cqm_occup_llc"
>>  MBM (Memory Bandwidth Monitoring)		"cqm_mbm_total", "cqm_mbm_local"
>>  MBA (Memory Bandwidth Allocation)		"mba"
>> -=============================================	================================
>> +SMBA (Slow Memory Bandwidth Allocation)         "smba"
>> +BMEC (Bandwidth Monitoring Event Configuration) "bmec"
>> +===============================================	================================
>>  
>>  To use the feature mount the file system::
>>  
>> @@ -161,6 +163,79 @@ with the following files:
>>  "mon_features":
>>  		Lists the monitoring events if
>>  		monitoring is enabled for the resource.
>> +                Example::
>> +
>> +                   # cat /sys/fs/resctrl/info/L3_MON/mon_features
>> +                   llc_occupancy
>> +                   mbm_total_bytes
>> +                   mbm_local_bytes
>> +
>> +                If the system supports Bandwidth Monitoring Event
>> +                Configuration (BMEC), then the bandwidth events will
>> +                be configurable. The output will be::
>> +
>> +                   # cat /sys/fs/resctrl/info/L3_MON/mon_features
>> +                   llc_occupancy
>> +                   mbm_total_bytes
>> +                   mbm_total_config
>> +                   mbm_local_bytes
>> +                   mbm_local_config
>> +
>> +"mbm_total_config", "mbm_local_config":
>> +        These files contain the current event configuration for the events
>> +        mbm_total_bytes and mbm_local_bytes, respectively, when the
>> +        Bandwidth Monitoring Event Configuration (BMEC) feature is supported.
>> +        The event configuration settings are domain specific and will affect
>> +        all the CPUs in the domain.
>> +
>> +        Following are the types of events supported:
>> +
>> +        ====    ========================================================
>> +        Bits    Description
>> +        ====    ========================================================
>> +        6       Dirty Victims from the QOS domain to all types of memory
>> +        5       Reads to slow memory in the non-local NUMA domain
>> +        4       Reads to slow memory in the local NUMA domain
>> +        3       Non-temporal writes to non-local NUMA domain
>> +        2       Non-temporal writes to local NUMA domain
>> +        1       Reads to memory in the non-local NUMA domain
>> +        0       Reads to memory in the local NUMA domain
>> +        ====    ========================================================
>> +
>> +        By default, the mbm_total_bytes configuration is set to 0x7f to count
>> +        all the event types and the mbm_local_bytes configuration is set to
>> +        0x15 to count all the local memory events.
>> +
>> +        Examples:
>> +
>> +        * To view the current configuration::
>> +          ::
>> +
>> +            # cat /sys/fs/resctrl/info/L3_MON/mbm_total_config
>> +            0=0x7f;1=0x7f;2=0x7f;3=0x7f
>> +
>> +            # cat /sys/fs/resctrl/info/L3_MON/mbm_local_config
>> +            0=0x15;1=0x15;3=0x15;4=0x15
>> +
>> +        * To change the mbm_total_bytes to count only reads on domain 0.
>> +          To achieve this, the bits 0, 1, 4 and 5 needs to be set which is
>> +          110011b (in hex 0x33).
>> +          ::
>> +
>> +            # echo  "0=0x33" > /sys/fs/resctrl/info/L3_MON/mbm_total_config
>> +
>> +            # cat /sys/fs/resctrl/info/L3_MON/mbm_total_config
>> +            0=0x33;1=0x7f;2=0x7f;3=0x7f
>> +
>> +        * To change the mbm_local_bytes to count all the slow memory reads
>> +          on domain 1. To achieve this, the bits 4 and 5 needs to be set
>> +          which is 110000b (in hex 0x30).
>> +          ::
>> +
>> +            # echo  "1=0x30" > /sys/fs/resctrl/info/L3_MON/mbm_local_config
>> +
>> +            # cat /sys/fs/resctrl/info/L3_MON/mbm_local_config
>> +            0=0x15;1=0x30;3=0x15;4=0x15
>>  
>>  "max_threshold_occupancy":
>>  		Read/write file provides the largest value (in
>> @@ -464,6 +539,25 @@ Memory bandwidth domain is L3 cache.
>>  
>>  	MB:<cache_id0>=bw_MBps0;<cache_id1>=bw_MBps1;...
>>  
>> +Slow Memory bandwidth Allocation (SMBA)
>> +-------------------------------------------------
>> +AMD hardware can support slow Memory bandwidth Allocation feature.
>> +Currently, CXL.memory is the only supported "slow" memory device.
>> +With the support of SMBA feature the hardware enables bandwidth
>> +allocation on the slow memory devices. If there are multiple slow
>> +memory devices in the system, then the throttling logic groups all
>> +the slow sources together and applies the limit on them as a whole.
>> +
>> +The presence of the SMBA feature(with CXL.memory) is independent
>> +of whether slow memory device is actually present in the system.
>> +If there is no slow memory in the system, then setting a SMBA limit
>> +will have no impact on the performance of the system.
>> +
>> +Slow Memory bandwidth domain is L3 cache.
>> +::
>> +
>> +	SMBA:<cache_id0>=bandwidth0;<cache_id1>=bandwidth1;...
>> +
>>  Reading/writing the schemata file
>>  ---------------------------------
>>  Reading the schemata file will show the state of all resources
>> @@ -479,6 +573,44 @@ which you wish to change.  E.g.
>>    L3DATA:0=fffff;1=fffff;2=3c0;3=fffff
>>    L3CODE:0=fffff;1=fffff;2=fffff;3=fffff
>>  
>> +Reading/writing the schemata file (on AMD systems)
>> +--------------------------------------------------
>> +Reading the schemata file will show the state of all resources
>> +on all domains. When writing the memory bandwidth allocation you
>> +only need to specify those values in an absolute number expressed
>> +in 1/8 GB/s increments. To allocate bandwidth limit of 2GB, you
>> +need to specify the value 16 (16 * 1/8 = 2). For example:
>> +::
>> +
>> +  # cat schemata
>> +    MB:0=2048;1=2048;2=2048;3=2048
>> +    L3:0=ffff;1=ffff;2=ffff;3=ffff
>> +
>> +  # echo "MB:1=16" > schemata
>> +  # cat schemata
>> +    MB:0=2048;1=  16;2=2048;3=2048
>> +    L3:0=ffff;1=ffff;2=ffff;3=ffff
>> +
>> +Reading/writing the schemata file (on AMD systems) with SMBA feature
>> +-------------------------------------------------------------------
> The heading above produces htmldocs warnings:
>
> Documentation/x86/resctrl.rst:595: WARNING: Title underline too short.
>
> Reading/writing the schemata file (on AMD systems) with SMBA feature
> -------------------------------------------------------------------
> Documentation/x86/resctrl.rst:595: WARNING: Title underline too short.
>
> Reading/writing the schemata file (on AMD systems) with SMBA feature
> -------------------------------------------------------------------
>
> I have applied the fixup:
Thanks
>
> ---- >8 ----
>
> diff --git a/Documentation/x86/resctrl.rst b/Documentation/x86/resctrl.rst
> index e2a59249d18322..145916828f2bae 100644
> --- a/Documentation/x86/resctrl.rst
> +++ b/Documentation/x86/resctrl.rst
> @@ -592,7 +592,7 @@ need to specify the value 16 (16 * 1/8 = 2). For example:
>      L3:0=ffff;1=ffff;2=ffff;3=ffff
>  
>  Reading/writing the schemata file (on AMD systems) with SMBA feature
> --------------------------------------------------------------------
> +--------------------------------------------------------------------
>  Reading the schemata file will show the state of all resources
>  on all domains. When writing the memory bandwidth allocation you
>  only need to specify those values in an absolute number expressed
>
>> +Reading the schemata file will show the state of all resources
>> +on all domains. When writing the memory bandwidth allocation you
>> +only need to specify those values in an absolute number expressed
>> +in 1/8 GB/s increments. To allocate bandwidth limit of 8GB, you
>> +need to specify the value 64 (64 * 1/8 = 8).  E.g.
>> +::
>> +
>> +  # cat schemata
>> +    SMBA:0=2048;1=2048;2=2048;3=2048
>> +      MB:0=2048;1=2048;2=2048;3=2048
>> +      L3:0=ffff;1=ffff;2=ffff;3=ffff
>> +
>> +  # echo "SMBA:1=64" > schemata
>> +  # cat schemata
>> +    SMBA:0=2048;1=  64;2=2048;3=2048
>> +      MB:0=2048;1=2048;2=2048;3=2048
>> +      L3:0=ffff;1=ffff;2=ffff;3=ffff
>> +
>>  Cache Pseudo-Locking
>>  ====================
>>  CAT enables a user to specify the amount of cache space that an
>>
>>
> The rest of prose can be improved:
>
> ---- >8 ----
>
> diff --git a/Documentation/x86/resctrl.rst b/Documentation/x86/resctrl.rst
> index 145916828f2bae..92b2c4e03a4a26 100644
> --- a/Documentation/x86/resctrl.rst
> +++ b/Documentation/x86/resctrl.rst
> @@ -217,9 +217,9 @@ with the following files:
>              # cat /sys/fs/resctrl/info/L3_MON/mbm_local_config
>              0=0x15;1=0x15;3=0x15;4=0x15
>  
> -        * To change the mbm_total_bytes to count only reads on domain 0.
> -          To achieve this, the bits 0, 1, 4 and 5 needs to be set which is
> -          110011b (in hex 0x33).
> +        * To change the mbm_total_bytes to count only reads on domain 0
> +          (the bits 0, 1, 4 and 5 needs to be set, which means 110011b
> +          {in hex 0x33}):
>            ::
>  
>              # echo  "0=0x33" > /sys/fs/resctrl/info/L3_MON/mbm_total_config
> @@ -228,8 +228,8 @@ with the following files:
>              0=0x33;1=0x7f;2=0x7f;3=0x7f
>  
>          * To change the mbm_local_bytes to count all the slow memory reads
> -          on domain 1. To achieve this, the bits 4 and 5 needs to be set
> -          which is 110000b (in hex 0x30).
> +          on domain 1 (the bits 4 and 5 needs to be set, which means 110000b
> +          {in hex 0x30}):
>            ::
>  
>              # echo  "1=0x30" > /sys/fs/resctrl/info/L3_MON/mbm_local_config
> @@ -540,20 +540,21 @@ Memory bandwidth domain is L3 cache.
>  	MB:<cache_id0>=bw_MBps0;<cache_id1>=bw_MBps1;...
>  
>  Slow Memory bandwidth Allocation (SMBA)
> --------------------------------------------------
> -AMD hardware can support slow Memory bandwidth Allocation feature.
> +---------------------------------------
> +AMD hardwares support Slow Memory bandwidth Allocation (SMBA) feature.
>  Currently, CXL.memory is the only supported "slow" memory device.
> -With the support of SMBA feature the hardware enables bandwidth
> -allocation on the slow memory devices. If there are multiple slow
> -memory devices in the system, then the throttling logic groups all
> -the slow sources together and applies the limit on them as a whole.
> +With the support of SMBA, the hardware enables bandwidth allocation
> +on the slow memory devices. If there are multiple such devices in the
> +system, the throttling logic groups all the slow sources together
> +and applies the limit on them as a whole.
>  
> -The presence of the SMBA feature(with CXL.memory) is independent
> -of whether slow memory device is actually present in the system.
> -If there is no slow memory in the system, then setting a SMBA limit
> -will have no impact on the performance of the system.
> +The presence of SMBA (with CXL.memory) is independent of slow memory
> +devices presence. If there is no such devices on the system, then
> +setting the configuring SMBA will have no impact on the performance
> +of the system.
>  
> -Slow Memory bandwidth domain is L3 cache.
> +The bandwidth domain for slow memory is L3 cache. Its schemata file
> +is formatted as:
>  ::
>  
>  	SMBA:<cache_id0>=bandwidth0;<cache_id1>=bandwidth1;...
> @@ -575,11 +576,13 @@ which you wish to change.  E.g.
>  
>  Reading/writing the schemata file (on AMD systems)
>  --------------------------------------------------
> -Reading the schemata file will show the state of all resources
> -on all domains. When writing the memory bandwidth allocation you
> -only need to specify those values in an absolute number expressed
> -in 1/8 GB/s increments. To allocate bandwidth limit of 2GB, you
> -need to specify the value 16 (16 * 1/8 = 2). For example:
> +Reading the schemata file will show the current bandwidth limit on all
> +domains. The allocated resources are in multiples of one eighth GB/s.
> +When writing to the file, you need to specify what cache id you wish to
> +configure the bandwidth limit.
> +
> +For example, to allocate 2GB/s limit on the first cache id:
> +
>  ::
>  
>    # cat schemata
> @@ -593,11 +596,11 @@ need to specify the value 16 (16 * 1/8 = 2). For example:
>  
>  Reading/writing the schemata file (on AMD systems) with SMBA feature
>  --------------------------------------------------------------------
> -Reading the schemata file will show the state of all resources
> -on all domains. When writing the memory bandwidth allocation you
> -only need to specify those values in an absolute number expressed
> -in 1/8 GB/s increments. To allocate bandwidth limit of 8GB, you
> -need to specify the value 64 (64 * 1/8 = 8).  E.g.
> +Reading and writing the schemata file is the same as without SMBA in
> +above section.
> +
> +For example, to allocate 8GB/s limit on the first cache id:
> +
>  ::
>  
>    # cat schemata
>
Thanks

Babu Moger
Re: [PATCH v6 12/12] Documentation/x86: Update resctrl_ui.rst for new features
Posted by Reinette Chatre 3 years, 5 months ago
Hi Babu,

Without opening any of the patches from this series, by just looking at the
subject line of this patch, it was immediately clear to me that you did not
follow my review feedback. Letting you know about the typo (resctrl_ui.rst does
not exist) in the subject line was one of the few things I mentioned about
v5 after v5 also did not follow review feedback from me in other areas.

Providing feedback is not a good use of time if it is ignored. 

Reinette
RE: [PATCH v6 12/12] Documentation/x86: Update resctrl_ui.rst for new features
Posted by Moger, Babu 3 years, 5 months ago
[AMD Official Use Only - General]

Hi Reinette,

> -----Original Message-----
> From: Reinette Chatre <reinette.chatre@intel.com>
> Sent: Monday, October 10, 2022 4:31 PM
> To: Moger, Babu <Babu.Moger@amd.com>; corbet@lwn.net;
> tglx@linutronix.de; mingo@redhat.com; bp@alien8.de
> Cc: fenghua.yu@intel.com; dave.hansen@linux.intel.com; x86@kernel.org;
> hpa@zytor.com; paulmck@kernel.org; akpm@linux-foundation.org;
> quic_neeraju@quicinc.com; rdunlap@infradead.org;
> damien.lemoal@opensource.wdc.com; songmuchun@bytedance.com;
> peterz@infradead.org; jpoimboe@kernel.org; pbonzini@redhat.com;
> chang.seok.bae@intel.com; pawan.kumar.gupta@linux.intel.com;
> jmattson@google.com; daniel.sneddon@linux.intel.com; Das1, Sandipan
> <Sandipan.Das@amd.com>; tony.luck@intel.com; james.morse@arm.com;
> linux-doc@vger.kernel.org; linux-kernel@vger.kernel.org;
> bagasdotme@gmail.com; eranian@google.com
> Subject: Re: [PATCH v6 12/12] Documentation/x86: Update resctrl_ui.rst for
> new features
> 
> Hi Babu,
> 
> Without opening any of the patches from this series, by just looking at the
> subject line of this patch, it was immediately clear to me that you did not follow
> my review feedback. Letting you know about the typo (resctrl_ui.rst does not
> exist) in the subject line was one of the few things I mentioned about
> v5 after v5 also did not follow review feedback from me in other areas.
> 
> Providing feedback is not a good use of time if it is ignored.

I am really sorry about that. I have checked multiple over. Noticed it now, that I missed one of your comments. But I have addressed all your other comments.
I will give few days to refresh these patches. You can wait for the next revision if you like.
Thanks
Babu