The current event configuration for mbm_local_bytes can be changed by
the user by writing to the configuration file
/sys/fs/resctrl/info/L3_MON/mbm_local_bytes_config.

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
====  ===========================================================

For example:
To change the mbm_local_bytes_config to count all the non-temporal writes
on domain 0, the bits 2 and 3 needs to be set which is 1100b (in hex 0xc).
Run the command.
    $echo  0=0xc > /sys/fs/resctrl/info/L3_MON/mbm_local_bytes_config

To change the mbm_local_bytes to count only reads to local NUMA domain 1,
the bit 0 needs to be set which 1b (in hex 0x1). Run the command.
    $echo  1=0x1 > /sys/fs/resctrl/info/L3_MON/mbm_local_bytes_config

Signed-off-by: Babu Moger <babu.moger@amd.com>
---
 arch/x86/kernel/cpu/resctrl/rdtgroup.c |   29 ++++++++++++++++++++++++++++-
 1 file changed, 28 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index 8a22a652a6e8..6897c480ae55 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -1641,6 +1641,32 @@ static ssize_t mbm_total_bytes_config_write(struct kernfs_open_file *of,
 	return ret ?: nbytes;
 }
 
+static ssize_t mbm_local_bytes_config_write(struct kernfs_open_file *of,
+					    char *buf, size_t nbytes,
+					    loff_t off)
+{
+	struct rdt_resource *r = of->kn->parent->priv;
+	int ret;
+
+	/* Valid input requires a trailing newline */
+	if (nbytes == 0 || buf[nbytes - 1] != '\n')
+		return -EINVAL;
+
+	cpus_read_lock();
+	mutex_lock(&rdtgroup_mutex);
+
+	rdt_last_cmd_clear();
+
+	buf[nbytes - 1] = '\0';
+
+	ret = mon_config_write(r, buf, QOS_L3_MBM_LOCAL_EVENT_ID);
+
+	mutex_unlock(&rdtgroup_mutex);
+	cpus_read_unlock();
+
+	return ret ?: nbytes;
+}
+
 /* rdtgroup information files for one cache resource. */
 static struct rftype res_common_files[] = {
 	{
@@ -1748,9 +1774,10 @@ static struct rftype res_common_files[] = {
 	},
 	{
 		.name		= "mbm_local_bytes_config",
-		.mode		= 0444,
+		.mode		= 0644,
 		.kf_ops		= &rdtgroup_kf_single_ops,
 		.seq_show	= mbm_local_bytes_config_show,
+		.write		= mbm_local_bytes_config_write,
 	},
 	{
 		.name		= "cpus",

Hi Babu,

On 12/1/2022 7:37 AM, Babu Moger wrote:
> The current event configuration for mbm_local_bytes can be changed by
> the user by writing to the configuration file
> /sys/fs/resctrl/info/L3_MON/mbm_local_bytes_config.
> 

Same comments about subject line and usage of "current".

> 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
> ====  ===========================================================
> 
> For example:
> To change the mbm_local_bytes_config to count all the non-temporal writes
> on domain 0, the bits 2 and 3 needs to be set which is 1100b (in hex 0xc).
> Run the command.
>     $echo  0=0xc > /sys/fs/resctrl/info/L3_MON/mbm_local_bytes_config
> 
> To change the mbm_local_bytes to count only reads to local NUMA domain 1,
> the bit 0 needs to be set which 1b (in hex 0x1). Run the command.
>     $echo  1=0x1 > /sys/fs/resctrl/info/L3_MON/mbm_local_bytes_config
> 
> Signed-off-by: Babu Moger <babu.moger@amd.com>
> ---
>  arch/x86/kernel/cpu/resctrl/rdtgroup.c |   29 ++++++++++++++++++++++++++++-
>  1 file changed, 28 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> index 8a22a652a6e8..6897c480ae55 100644
> --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> @@ -1641,6 +1641,32 @@ static ssize_t mbm_total_bytes_config_write(struct kernfs_open_file *of,
>  	return ret ?: nbytes;
>  }
>  
> +static ssize_t mbm_local_bytes_config_write(struct kernfs_open_file *of,
> +					    char *buf, size_t nbytes,
> +					    loff_t off)
> +{
> +	struct rdt_resource *r = of->kn->parent->priv;
> +	int ret;
> +
> +	/* Valid input requires a trailing newline */
> +	if (nbytes == 0 || buf[nbytes - 1] != '\n')
> +		return -EINVAL;
> +
> +	cpus_read_lock();
> +	mutex_lock(&rdtgroup_mutex);
> +
> +	rdt_last_cmd_clear();
> +
> +	buf[nbytes - 1] = '\0';
> +
> +	ret = mon_config_write(r, buf, QOS_L3_MBM_LOCAL_EVENT_ID);
> +
> +	mutex_unlock(&rdtgroup_mutex);
> +	cpus_read_unlock();
> +
> +	return ret ?: nbytes;
> +}
> +
>  /* rdtgroup information files for one cache resource. */
>  static struct rftype res_common_files[] = {
>  	{
> @@ -1748,9 +1774,10 @@ static struct rftype res_common_files[] = {
>  	},
>  	{
>  		.name		= "mbm_local_bytes_config",
> -		.mode		= 0444,
> +		.mode		= 0644,
>  		.kf_ops		= &rdtgroup_kf_single_ops,
>  		.seq_show	= mbm_local_bytes_config_show,
> +		.write		= mbm_local_bytes_config_write,
>  	},
>  	{
>  		.name		= "cpus",
> 
> 

With the subject and changelog comments addressed:

Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>

Reinette

[AMD Official Use Only - General]

Hi Reinette,

> -----Original Message-----
> From: Reinette Chatre <reinette.chatre@intel.com>
> Sent: Thursday, December 15, 2022 12:26 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; christophe.leroy@csgroup.eu;
> jarkko@kernel.org; adrian.hunter@intel.com; quic_jiles@quicinc.com;
> peternewman@google.com
> Subject: Re: [PATCH v9 11/13] x86/resctrl: Add sysfs interface to write
> mbm_local_bytes_config
> 
> Hi Babu,
> 
> On 12/1/2022 7:37 AM, Babu Moger wrote:
> > The current event configuration for mbm_local_bytes can be changed by
> > the user by writing to the configuration file
> > /sys/fs/resctrl/info/L3_MON/mbm_local_bytes_config.
> >
> 
> Same comments about subject line and usage of "current".

Sure,
> 
> > 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
> > ====
> ===========================================================
> >
> > For example:
> > To change the mbm_local_bytes_config to count all the non-temporal
> > writes on domain 0, the bits 2 and 3 needs to be set which is 1100b (in hex
> 0xc).
> > Run the command.
> >     $echo  0=0xc > /sys/fs/resctrl/info/L3_MON/mbm_local_bytes_config
> >
> > To change the mbm_local_bytes to count only reads to local NUMA domain
> > 1, the bit 0 needs to be set which 1b (in hex 0x1). Run the command.
> >     $echo  1=0x1 > /sys/fs/resctrl/info/L3_MON/mbm_local_bytes_config
> >
> > Signed-off-by: Babu Moger <babu.moger@amd.com>
> > ---
> >  arch/x86/kernel/cpu/resctrl/rdtgroup.c |   29
> ++++++++++++++++++++++++++++-
> >  1 file changed, 28 insertions(+), 1 deletion(-)
> >
> > diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> > b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> > index 8a22a652a6e8..6897c480ae55 100644
> > --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> > +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> > @@ -1641,6 +1641,32 @@ static ssize_t
> mbm_total_bytes_config_write(struct kernfs_open_file *of,
> >  	return ret ?: nbytes;
> >  }
> >
> > +static ssize_t mbm_local_bytes_config_write(struct kernfs_open_file *of,
> > +					    char *buf, size_t nbytes,
> > +					    loff_t off)
> > +{
> > +	struct rdt_resource *r = of->kn->parent->priv;
> > +	int ret;
> > +
> > +	/* Valid input requires a trailing newline */
> > +	if (nbytes == 0 || buf[nbytes - 1] != '\n')
> > +		return -EINVAL;
> > +
> > +	cpus_read_lock();
> > +	mutex_lock(&rdtgroup_mutex);
> > +
> > +	rdt_last_cmd_clear();
> > +
> > +	buf[nbytes - 1] = '\0';
> > +
> > +	ret = mon_config_write(r, buf, QOS_L3_MBM_LOCAL_EVENT_ID);
> > +
> > +	mutex_unlock(&rdtgroup_mutex);
> > +	cpus_read_unlock();
> > +
> > +	return ret ?: nbytes;
> > +}
> > +
> >  /* rdtgroup information files for one cache resource. */  static
> > struct rftype res_common_files[] = {
> >  	{
> > @@ -1748,9 +1774,10 @@ static struct rftype res_common_files[] = {
> >  	},
> >  	{
> >  		.name		= "mbm_local_bytes_config",
> > -		.mode		= 0444,
> > +		.mode		= 0644,
> >  		.kf_ops		= &rdtgroup_kf_single_ops,
> >  		.seq_show	= mbm_local_bytes_config_show,
> > +		.write		= mbm_local_bytes_config_write,
> >  	},
> >  	{
> >  		.name		= "cpus",
> >
> >
> 
> With the subject and changelog comments addressed:
> 
> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>

Thanks
Babu
> 
> Reinette