[PATCH v18 07/17] x86/resctrl: Prepare for new Sub-NUMA (SNC) cluster monitor files

Tony Luck
2024-05-15T22:23:39Z

When SNC is enabled monitoring data is collected at the SNC node
granularity, but must be reported at L3-cache granularity for
backwards compatibility in addition to reporting at the node
level.

Add a mon_display_scope field to the rdt_resource structure to track
reporting scope. Default is for non-SNC systems where both scopes
are the same.

This is the first step to an eventual goal of monitor reporting files
like this (for a system with two SNC nodes per L3):

$ cd /sys/fs/resctrl/mon_data
$ tree mon_L3_00
mon_L3_00 <- 00 here is L3 cache id
├── llc_occupancy \ These files provide legacy support
├── mbm_local_bytes > for non-SNC aware monitor apps
├── mbm_total_bytes / that expect data at L3 cache level
├── mon_sub_L3_00 <- 00 here is SNC node id
│   ├── llc_occupancy \ These files are finer grained
│   ├── mbm_local_bytes > data from each SNC node
│   └── mbm_total_bytes /
└── mon_sub_L3_01
├── llc_occupancy \
├── mbm_local_bytes > As above, but for node 1.
└── mbm_total_bytes /

Signed-off-by: Tony Luck <tony.luck@intel.com>
---
include/linux/resctrl.h | 2 ++
arch/x86/kernel/cpu/resctrl/core.c | 1 +
2 files changed, 3 insertions(+)

diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h
index 5c7775343c3e..98c0ff8ba005 100644
--- a/include/linux/resctrl.h
+++ b/include/linux/resctrl.h
@@ -187,6 +187,7 @@ enum resctrl_scope {
* @num_rmid: Number of RMIDs available
* @ctrl_scope: Scope of this resource for control functions
* @mon_scope: Scope of this resource for monitor functions
+ * @mon_display_scope: Scope for user reporting monitor functions
* @cache: Cache allocation related data
* @membw: If the component has bandwidth controls, their properties.
* @ctrl_domains: RCU list of all control domains for this resource
@@ -207,6 +208,7 @@ struct rdt_resource {
int num_rmid;
enum resctrl_scope ctrl_scope;
enum resctrl_scope mon_scope;
+ enum resctrl_scope mon_display_scope;
struct resctrl_cache cache;
struct resctrl_membw membw;
struct list_head ctrl_domains;
diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c
index bfa9d3a429fd..15856254fea7 100644
--- a/arch/x86/kernel/cpu/resctrl/core.c
+++ b/arch/x86/kernel/cpu/resctrl/core.c
@@ -71,6 +71,7 @@ struct rdt_hw_resource rdt_resources_all[] = {
.name = "L3",
.ctrl_scope = RESCTRL_L3_CACHE,
.mon_scope = RESCTRL_L3_CACHE,
+ .mon_display_scope = RESCTRL_L3_CACHE,
.ctrl_domains = ctrl_domain_init(RDT_RESOURCE_L3),
.mon_domains = mon_domain_init(RDT_RESOURCE_L3),
.parse_ctrlval = parse_cbm,
--
2.44.0