The 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
Reviewed-by: Reinette Chatre <reinette.chatre@xxxxxxxxx>
Signed-off-by: Babu Moger <babu.moger@xxxxxxx>
---
arch/x86/kernel/cpu/resctrl/rdtgroup.c | 27 +++++++++++++++++++++++++-
1 file changed, 26 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index 03284a61c1a0..5990589f8a21 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -1638,6 +1638,30 @@ 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;
+
+ 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);
+
+ return ret ?: nbytes;
+}
+
/* rdtgroup information files for one cache resource. */
static struct rftype res_common_files[] = {
{
@@ -1745,9 +1769,10 @@ 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",
--
2.34.1
