Introduce rdtgroup_assign_enable_write to enable ABMC mode.
Users can enable the feature by the following command.
$echo 1 > /sys/fs/resctrl/info/L3_MON/mbm_assign_enable
Signed-off-by: Babu Moger <babu.moger@xxxxxxx>
---
v2: This is new patch to enable/disable ABMC without mounting the filesystem.
---
Documentation/arch/x86/resctrl.rst | 6 +++++
arch/x86/kernel/cpu/resctrl/rdtgroup.c | 34 +++++++++++++++++++++++++-
2 files changed, 39 insertions(+), 1 deletion(-)
diff --git a/Documentation/arch/x86/resctrl.rst b/Documentation/arch/x86/resctrl.rst
index f94a4d314690..f09239cb93e8 100644
--- a/Documentation/arch/x86/resctrl.rst
+++ b/Documentation/arch/x86/resctrl.rst
@@ -273,6 +273,12 @@ with the following files:
assignment for monitoring. Feature provides an option to assign the RMID
to the hardware counter and monitor the bandwidth for a longer duration.
The assigned RMID will be active until the user unassigns it.
+ By default, the feature is disabled. Feature can be enabled by writing 1.
+ ::
+
+ # cat /sys/fs/resctrl/info/L3_MON/mbm_assign_enable
+ 0
+ # echo 1 > /sys/fs/resctrl/info/L3_MON/mbm_assign_enable
"max_threshold_occupancy":
Read/write file provides the largest value (in
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index 4f160dbf6376..9c8db9562c91 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -833,6 +833,37 @@ static int rdtgroup_mbm_assign_enable_show(struct kernfs_open_file *of,
return 0;
}
+static ssize_t rdtgroup_mbm_assign_enable_write(struct kernfs_open_file *of,
+ char *buf, size_t nbytes,
+ loff_t off)
+{
+ struct rdt_resource *r = of->kn->parent->priv;
+ struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r);
+ struct rdtgroup *rdtgrp;
+ unsigned int enable;
+ int ret;
+
+ if (!r->mbm_assign_capable)
+ return -EINVAL;
+
+ ret = kstrtouint(buf, 0, &enable);
+ if (ret)
+ return ret;
+
+ rdtgrp = rdtgroup_kn_lock_live(of->kn);
+ if (!rdtgrp) {
+ rdtgroup_kn_unlock(of->kn);
+ return -EINVAL;
+ }
+
+ if(hw_res->abmc_enabled != enable)
+ ret = resctrl_arch_set_abmc_enabled(r->rid, enable);
+
+ rdtgroup_kn_unlock(of->kn);
+
+ return ret ?: nbytes;
+}
+
#ifdef CONFIG_PROC_CPU_RESCTRL
/*
@@ -1891,9 +1922,10 @@ static struct rftype res_common_files[] = {
},
{
.name = "mbm_assign_enable",
- .mode = 0444,
+ .mode = 0644,
.kf_ops = &rdtgroup_kf_single_ops,
.seq_show = rdtgroup_mbm_assign_enable_show,
+ .write = rdtgroup_mbm_assign_enable_write,
},
{
.name = "cpus",
--
2.34.1
