Hi Babu,
On 7/3/24 2:48 PM, Babu Moger wrote:
Provide the interface to list the monitor states of all the resctrl
groups in ABMC mode.
Example:
$cat /sys/fs/resctrl/info/L3_MON/mbm_control
List follows the following format:
"<CTRL_MON group>/<MON group>/<domain_id>=<flags>"
Format for specific type of groups:
- Default CTRL_MON group:
"//<domain_id>=<flags>"
- Non-default CTRL_MON group:
"<CTRL_MON group>//<domain_id>=<flags>"
- Child MON group of default CTRL_MON group:
"/<MON group>/<domain_id>=<flags>"
- Child MON group of non-default CTRL_MON group:
"<CTRL_MON group>/<MON group>/<domain_id>=<flags>"
Flags can be one of the following:
t MBM total event is enabled
l MBM local event is enabled
tl Both total and local MBM events are enabled
_ None of the MBM events are enabled
Signed-off-by: Babu Moger <babu.moger@xxxxxxx>
---
v5: Replaced "assignment flags" with "flags".
Changes related to mon structure.
Changes related renaming the interface from mbm_assign_control to
mbm_control.
v4: Added functionality to query domain specific assigment in.
rdtgroup_abmc_dom_state().
v3: New patch.
Addresses the feedback to provide the global assignment interface.
https://lore.kernel.org/lkml/c73f444b-83a1-4e9a-95d3-54c5165ee782@xxxxxxxxx/
---
Documentation/arch/x86/resctrl.rst | 54 ++++++++++
arch/x86/kernel/cpu/resctrl/monitor.c | 1 +
arch/x86/kernel/cpu/resctrl/rdtgroup.c | 130 +++++++++++++++++++++++++
3 files changed, 185 insertions(+)
diff --git a/Documentation/arch/x86/resctrl.rst b/Documentation/arch/x86/resctrl.rst
index 4c41c5622627..05fee779e109 100644
--- a/Documentation/arch/x86/resctrl.rst
+++ b/Documentation/arch/x86/resctrl.rst
@@ -304,6 +304,60 @@ with the following files:
"num_mbm_cntrs":
The number of monitoring counters available for assignment.
+"mbm_control":
+ Available when ABMC features are supported.
"Available when ABMC features are supported." can be dropped
+ Reports the resctrl group and monitor status of each group.
+
+ List follows the following format:
+ "<CTRL_MON group>/<MON group>/<domain_id>=<flags>"
+
+ Format for specific type of grpups:
grpups -> groups
+
+ * Default CTRL_MON group:
+ "//<domain_id>=<flags>"
+
+ * Non-default CTRL_MON group:
+ "<CTRL_MON group>//<domain_id>=<flags>"
+
+ * Child MON group of default CTRL_MON group:
+ "/<MON group>/<domain_id>=<flags>"
+
+ * Child MON group of non-default CTRL_MON group:
+ "<CTRL_MON group>/<MON group>/<domain_id>=<flags>"
+
+ Flags can be one of the following:
+ ::
+
+ t MBM total event is enabled.
+ l MBM local event is enabled.
+ tl Both total and local MBM events are enabled.
+ _ None of the MBM events are enabled.
+
+ Examples:
+ ::
+
+ # mkdir /sys/fs/resctrl/mon_groups/child_default_mon_grp
+ # mkdir /sys/fs/resctrl/non_default_ctrl_mon_grp
+ # mkdir /sys/fs/resctrl/non_default_ctrl_mon_grp/mon_groups/child_non_default_mon_grp
+
+ # cat /sys/fs/resctrl/info/L3_MON/mbm_control
+ non_default_ctrl_mon_grp//0=tl;1=tl;
+ non_default_ctrl_mon_grp/child_non_default_mon_grp/0=tl;1=tl;
+ //0=tl;1=tl;
+ /child_default_mon_grp/0=tl;1=tl;
+
+ There are four resctrl groups. All the groups have total and local events are
+ enabled on domain 0 and 1.
"All the groups have total and local events are enabled" -> "All the groups have total and local events enabled"?
+
The text below seems to repeat ealier description.
+ non_default_ctrl_mon_grp// - This is a non-default CTRL_MON group.
+
+ non_default_ctrl_mon_grp/child_non_default_mon_grp/ - This is a child monitor
+ group of non-default CTRL_MON group.
+
+ // - This is a default CTRL_MON group.
+
+ /child_default_mon_grp/ - This is a child monitor group of default CTRL_MON group.
+
"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 b96b0a8bd7d3..684730f1a72d 100644
--- a/arch/x86/kernel/cpu/resctrl/monitor.c
+++ b/arch/x86/kernel/cpu/resctrl/monitor.c
@@ -1244,6 +1244,7 @@ int __init rdt_get_mon_l3_config(struct rdt_resource *r)
r->mon.num_mbm_cntrs = 64;
resctrl_file_fflags_init("num_mbm_cntrs", RFTYPE_MON_INFO);
+ resctrl_file_fflags_init("mbm_control", RFTYPE_MON_INFO);
Shouldn't this file always be present?
}
}
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index d978668c8865..0de9f23d5389 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -944,6 +944,130 @@ static ssize_t rdtgroup_mbm_mode_write(struct kernfs_open_file *of,
return ret ?: nbytes;
}
+static void rdtgroup_abmc_dom_cfg(void *info)
+{
+ u64 *msrval = info;
+
+ wrmsrl(MSR_IA32_L3_QOS_ABMC_CFG, *msrval);
+ rdmsrl(MSR_IA32_L3_QOS_ABMC_DSC, *msrval);
+}
+
+/*
+ * Writing the counter id with CfgEn=0 on L3_QOS_ABMC_CFG and reading
+ * L3_QOS_ABMC_DSC back will return configuration of the counter
+ * specified.
Can this be expanded to explain what the return values mean?
+ */
+static int rdtgroup_abmc_dom_state(struct rdt_mon_domain *d, u32 cntr_id,
+ u32 rmid)
+{
+ union l3_qos_abmc_cfg abmc_cfg = { 0 };
+
+ abmc_cfg.split.cfg_en = 0;
+ abmc_cfg.split.cntr_id = cntr_id;
+
+ smp_call_function_any(&d->hdr.cpu_mask, rdtgroup_abmc_dom_cfg,
+ &abmc_cfg, 1);
+
+ if (abmc_cfg.split.cntr_en && abmc_cfg.split.bw_src == rmid)
+ return 0;
+ else
+ return -1;
+}
+
+static char *rdtgroup_mon_state_to_str(struct rdtgroup *rdtgrp,
+ struct rdt_mon_domain *d, char *str)
+{
+ char *tmp = str;
+ int dom_state = ASSIGN_NONE;
reverse fir
+
+ /*
+ * Query the monitor state for the domain.
+ * Index 0 for evtid == QOS_L3_MBM_TOTAL_EVENT_ID
+ * Index 1 for evtid == QOS_L3_MBM_LOCAL_EVENT_ID
Why not use the helper?
+ */
+ if (rdtgrp->mon.cntr_id[0] != MON_CNTR_UNSET)
+ if (!rdtgroup_abmc_dom_state(d, rdtgrp->mon.cntr_id[0], rdtgrp->mon.rmid))
+ dom_state |= ASSIGN_TOTAL;
+
+ if (rdtgrp->mon.cntr_id[1] != MON_CNTR_UNSET)
+ if (!rdtgroup_abmc_dom_state(d, rdtgrp->mon.cntr_id[1], rdtgrp->mon.rmid))
+ dom_state |= ASSIGN_LOCAL;
+
+ switch (dom_state) {
+ case ASSIGN_NONE:
+ *tmp++ = '_';
+ break;
+ case (ASSIGN_TOTAL | ASSIGN_LOCAL):
+ *tmp++ = 't';
+ *tmp++ = 'l';
+ break;
+ case ASSIGN_TOTAL:
+ *tmp++ = 't';
+ break;
+ case ASSIGN_LOCAL:
+ *tmp++ = 'l';
+ break;
+ default:
+ break;
+ }
This switch statement does not scale. Adding new flags will be painful. Can flags not
just incrementally be printed as learned from hardware with "_" printed as last resort?
This would elimininate need for these "ASSIGN" flags.
+
+ *tmp = '\0';
+ return str;
+}
+
+static int rdtgroup_mbm_control_show(struct kernfs_open_file *of,
+ struct seq_file *s, void *v)
+{
+ struct rdt_resource *r = of->kn->parent->priv;
+ struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r);
+ struct rdt_mon_domain *dom;
+ struct rdtgroup *rdtg;
+ int grp_default = 0;
+ char str[10];
+
+ if (!hw_res->abmc_enabled) {
+ rdt_last_cmd_puts("ABMC feature is not enabled\n");
+ return -EINVAL;
+ }
+
+ mutex_lock(&rdtgroup_mutex);
+
+ list_for_each_entry(rdtg, &rdt_all_groups, rdtgroup_list) {
+ struct rdtgroup *crg;
+
+ if (rdtg == &rdtgroup_default) {
+ grp_default = 1;
+ seq_puts(s, "//");
+ } else {
+ grp_default = 0;
+ seq_printf(s, "%s//", rdtg->kn->name);
+ }
Isn't the default resource group's name already empty string? That should
eliminate the need for this special handling, no?
+
+ list_for_each_entry(dom, &r->mon_domains, hdr.list)
+ seq_printf(s, "%d=%s;", dom->hdr.id,
+ rdtgroup_mon_state_to_str(rdtg, dom, str));
+ seq_putc(s, '\n');
+
+ list_for_each_entry(crg, &rdtg->mon.crdtgrp_list,
+ mon.crdtgrp_list) {
+ if (grp_default)
+ seq_printf(s, "/%s/", crg->kn->name);
+ else
+ seq_printf(s, "%s/%s/", rdtg->kn->name,
+ crg->kn->name);
+
Same here .... with default group having name of empty string it can just be
printed directly, no?
+ list_for_each_entry(dom, &r->mon_domains, hdr.list)
+ seq_printf(s, "%d=%s;", dom->hdr.id,
+ rdtgroup_mon_state_to_str(crg, dom, str));
+ seq_putc(s, '\n');
+ }
+ }
+
+ mutex_unlock(&rdtgroup_mutex);
+
+ return 0;
+}
+
#ifdef CONFIG_PROC_CPU_RESCTRL
/*
@@ -2156,6 +2280,12 @@ static struct rftype res_common_files[] = {
.kf_ops = &rdtgroup_kf_single_ops,
.seq_show = rdtgroup_num_mbm_cntrs_show,
},
+ {
+ .name = "mbm_control",
+ .mode = 0444,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .seq_show = rdtgroup_mbm_control_show,
+ },
{
.name = "cpus_list",
.mode = 0644,
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