Hi Reinette,
On 2/5/2025 6:19 PM, Reinette Chatre wrote:
Hi Babu,
On 1/22/25 12:20 PM, Babu Moger wrote:
Provide the interface to display the number of monitoring counters
available for assignment in each domain when mbm_cntr_assign is enabled.
"when mbm_cntr_assign is enabled" -> "when mbm_cntr_assign mode is enabled"?
Sure.
Signed-off-by: Babu Moger <babu.moger@xxxxxxx>
---
---
Documentation/arch/x86/resctrl.rst | 8 +++++
arch/x86/kernel/cpu/resctrl/monitor.c | 1 +
arch/x86/kernel/cpu/resctrl/rdtgroup.c | 46 ++++++++++++++++++++++++++
3 files changed, 55 insertions(+)
diff --git a/Documentation/arch/x86/resctrl.rst b/Documentation/arch/x86/resctrl.rst
index 31ff764deeeb..99cae75559b0 100644
--- a/Documentation/arch/x86/resctrl.rst
+++ b/Documentation/arch/x86/resctrl.rst
@@ -299,6 +299,14 @@ with the following files:
memory bandwidth tracking to a single memory bandwidth event per
monitoring group.
+"available_mbm_cntrs":
+ The number of monitoring counters available for assignment in each
+ domain when mbm_cntr_assign mode is enabled on the system.
+ ::
+
Documentation jumps in with some hardcoded values that may cause confusion.
It looks to be missing something like (and looking back this also applies
to "num_mbm_cntrs"):
"For example, on a system with 30 available monitoring/(hardware?) counters in
each of its L3 domains:"
Sure.
+ # cat /sys/fs/resctrl/info/L3_MON/available_mbm_cntrs
+ 0=30;1=30
+
"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 6fe9e610e9a0..f2bf5b13465d 100644
--- a/arch/x86/kernel/cpu/resctrl/monitor.c
+++ b/arch/x86/kernel/cpu/resctrl/monitor.c
@@ -1234,6 +1234,7 @@ int __init rdt_get_mon_l3_config(struct rdt_resource *r)
cpuid_count(0x80000020, 5, &eax, &ebx, &ecx, &edx);
r->mon.num_mbm_cntrs = (ebx & GENMASK(15, 0)) + 1;
resctrl_file_fflags_init("num_mbm_cntrs", RFTYPE_MON_INFO);
+ resctrl_file_fflags_init("available_mbm_cntrs", RFTYPE_MON_INFO);
}
}
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index 75a3b56996ca..2b86124c336b 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -888,6 +888,46 @@ static int resctrl_num_mbm_cntrs_show(struct kernfs_open_file *of,
return 0;
}
+static int resctrl_available_mbm_cntrs_show(struct kernfs_open_file *of,
+ struct seq_file *s, void *v)
+{
+ struct rdt_resource *r = of->kn->parent->priv;
+ struct rdt_mon_domain *dom;
+ bool sep = false;
+ u32 cntrs, i;
+ int ret = 0;
+
+ cpus_read_lock();
+ mutex_lock(&rdtgroup_mutex);
+
Missing rdt_last_cmd_clear()?
Yes.
+ if (!resctrl_arch_mbm_cntr_assign_enabled(r)) {
+ rdt_last_cmd_puts("mbm_cntr_assign mode is not enabled\n");
+ ret = -EINVAL;
+ goto unlock_cntrs_show;
+ }
+
+ list_for_each_entry(dom, &r->mon_domains, hdr.list) {
+ if (sep)
+ seq_puts(s, ";");
The one character prints can be simplified with a seq_putc().
Sure.
seq_putc(s, ';');
+
+ cntrs = 0;
+ for (i = 0; i < r->mon.num_mbm_cntrs; i++) {
+ if (!dom->cntr_cfg[i].rdtgrp)
+ cntrs++;
+ }
+
+ seq_printf(s, "%d=%d", dom->hdr.id, cntrs);
I expect cntrs to need %u?
Sure.
+ sep = true;
+ }
+ seq_puts(s, "\n");
+
+unlock_cntrs_show:
+ mutex_unlock(&rdtgroup_mutex);
+ cpus_read_unlock();
+
+ return ret;
+}
+
#ifdef CONFIG_PROC_CPU_RESCTRL
/*
@@ -1916,6 +1956,12 @@ static struct rftype res_common_files[] = {
.kf_ops = &rdtgroup_kf_single_ops,
.seq_show = resctrl_num_mbm_cntrs_show,
},
+ {
+ .name = "available_mbm_cntrs",
+ .mode = 0444,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .seq_show = resctrl_available_mbm_cntrs_show,
+ },
{
.name = "cpus",
.mode = 0644,
Reinette
Thanks
Babu
