x86/resctrl: Prepare for new Sub-NUMA Cluster (SNC) monitor files

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 "ci" field to the rdt_mon_domain structure to save the cache information
about the enclosing L3 cache for the domain.  This provides:

1) The cache id which is needed to compose the name of the legacy monitoring
   directory, and to determine which domains should be summed to provide
   L3-scoped data.

2) The shared_cpu_map which is needed to determine which CPUs can be used to
   read the RMID counters with the MSR interface.

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		/

  [ bp: Massage commit message. ]

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Link: https://lore.kernel.org/r/20240628215619.76401-9-tony.luck@intel.com

diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c
index b86c525d0620a1b97867caf38856b3ca0afa8c34..95ef8fe3cb509c49a05a98fffe69d4f034527bf8 100644 (file)
--- a/arch/x86/kernel/cpu/resctrl/core.c
+++ b/arch/x86/kernel/cpu/resctrl/core.c
@@ -19,7 +19,6 @@
 #include <linux/cpu.h>
 #include <linux/slab.h>
 #include <linux/err.h>
-#include <linux/cacheinfo.h>
 #include <linux/cpuhotplug.h>
 
 #include <asm/cpu_device_id.h>
@@ -608,6 +607,12 @@ static void domain_add_cpu_mon(int cpu, struct rdt_resource *r)
        d = &hw_dom->d_resctrl;
        d->hdr.id = id;
        d->hdr.type = RESCTRL_MON_DOMAIN;
+       d->ci = get_cpu_cacheinfo_level(cpu, RESCTRL_L3_CACHE);
+       if (!d->ci) {
+               pr_warn_once("Can't find L3 cache for CPU:%d resource %s\n", cpu, r->name);
+               mon_domain_free(hw_dom);
+               return;
+       }
        cpumask_set_cpu(cpu, &d->hdr.cpu_mask);
 
        if (arch_domain_mbm_alloc(r->num_rmid, hw_dom)) {

diff --git a/arch/x86/kernel/cpu/resctrl/pseudo_lock.c b/arch/x86/kernel/cpu/resctrl/pseudo_lock.c
index 70f0069b87d84fb5ebe1b21fd587ac8d70b90387..e69489d48625bd23ec34232024d474f90ed2291c 100644 (file)
--- a/arch/x86/kernel/cpu/resctrl/pseudo_lock.c
+++ b/arch/x86/kernel/cpu/resctrl/pseudo_lock.c
@@ -11,7 +11,6 @@
 
 #define pr_fmt(fmt)    KBUILD_MODNAME ": " fmt
 
-#include <linux/cacheinfo.h>
 #include <linux/cpu.h>
 #include <linux/cpumask.h>
 #include <linux/debugfs.h>

diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index d3b0fa9582669646e4cb9a0f62776d668adee327..70d41a8fd78863bb8855c867f86cd547eda90226 100644 (file)
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -12,7 +12,6 @@
 
 #define pr_fmt(fmt)    KBUILD_MODNAME ": " fmt
 
-#include <linux/cacheinfo.h>
 #include <linux/cpu.h>
 #include <linux/debugfs.h>
 #include <linux/fs.h>

diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h
index 64b6ad1b22a14bdeb658cfeab6e3829e64994594..b0875b99e8111e2d98e5664cceb1decf46f380a4 100644 (file)
--- a/include/linux/resctrl.h
+++ b/include/linux/resctrl.h
@@ -2,6 +2,7 @@
 #ifndef _RESCTRL_H
 #define _RESCTRL_H
 
+#include <linux/cacheinfo.h>
 #include <linux/kernel.h>
 #include <linux/list.h>
 #include <linux/pid.h>
@@ -96,6 +97,7 @@ struct rdt_ctrl_domain {
 /**
  * struct rdt_mon_domain - group of CPUs sharing a resctrl monitor resource
  * @hdr:               common header for different domain types
+ * @ci:                        cache info for this domain
  * @rmid_busy_llc:     bitmap of which limbo RMIDs are above threshold
  * @mbm_total:         saved state for MBM total bandwidth
  * @mbm_local:         saved state for MBM local bandwidth
@@ -106,6 +108,7 @@ struct rdt_ctrl_domain {
  */
 struct rdt_mon_domain {
        struct rdt_domain_hdr           hdr;
+       struct cacheinfo                *ci;
        unsigned long                   *rmid_busy_llc;
        struct mbm_state                *mbm_total;
        struct mbm_state                *mbm_local;