x86/intel_rdt/mbm: Add mbm counter initialization

MBM counters are monotonically increasing counts representing the total
memory bytes at a particular time. In order to calculate total_bytes for
an rdtgroup, we store the value of the counter when we create an
rdtgroup or when a new domain comes online.

When the total_bytes(all memory controller bytes) or local_bytes(local
memory controller bytes) file in "mon_data" is read it shows the
total bytes for that rdtgroup since its creation. User can snapshot this
at different time intervals to obtain bytes/second.

Signed-off-by: Vikas Shivappa <vikas.shivappa@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: ravi.v.shankar@intel.com
Cc: tony.luck@intel.com
Cc: fenghua.yu@intel.com
Cc: peterz@infradead.org
Cc: eranian@google.com
Cc: vikas.shivappa@intel.com
Cc: ak@linux.intel.com
Cc: davidcc@google.com
Cc: reinette.chatre@intel.com
Link: http://lkml.kernel.org/r/1501017287-28083-28-git-send-email-vikas.shivappa@linux.intel.com

diff --git a/arch/x86/kernel/cpu/intel_rdt.h b/arch/x86/kernel/cpu/intel_rdt.h
index 2137d5e5580322171c91078db08f07dec22763d2..f160403324d3e48f44aa478d200bbd40b5f84e5a 100644 (file)
--- a/arch/x86/kernel/cpu/intel_rdt.h
+++ b/arch/x86/kernel/cpu/intel_rdt.h
@@ -55,6 +55,7 @@ struct rmid_read {
        struct rdtgroup         *rgrp;
        struct rdt_domain       *d;
        int                     evtid;
+       bool                    first;
        u64                     val;
 };
 
@@ -263,6 +264,12 @@ static inline bool is_mbm_enabled(void)
        return (is_mbm_total_enabled() || is_mbm_local_enabled());
 }
 
+static inline bool is_mbm_event(int e)
+{
+       return (e >= QOS_L3_MBM_TOTAL_EVENT_ID &&
+               e <= QOS_L3_MBM_LOCAL_EVENT_ID);
+}
+
 /**
  * struct rdt_resource - attributes of an RDT resource
  * @rid:               The index of the resource
@@ -402,5 +409,7 @@ void rmdir_mondata_subdir_allrdtgrp(struct rdt_resource *r,
                                    unsigned int dom_id);
 void mkdir_mondata_subdir_allrdtgrp(struct rdt_resource *r,
                                    struct rdt_domain *d);
+void mon_event_read(struct rmid_read *rr, struct rdt_domain *d,
+                   struct rdtgroup *rdtgrp, int evtid, int first);
 
 #endif /* _ASM_X86_INTEL_RDT_H */

diff --git a/arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c b/arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c
index cf8e2c776440d7a75076f42ed893722f21a1174f..f6ea94f8954a7d5e862b4f25a98b963d664007ec 100644 (file)
--- a/arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c
+++ b/arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c
@@ -287,7 +287,7 @@ int rdtgroup_schemata_show(struct kernfs_open_file *of,
 }
 
 void mon_event_read(struct rmid_read *rr, struct rdt_domain *d,
-                   struct rdtgroup *rdtgrp, int evtid)
+                   struct rdtgroup *rdtgrp, int evtid, int first)
 {
        /*
         * setup the parameters to send to the IPI to read the data.
@@ -296,6 +296,7 @@ void mon_event_read(struct rmid_read *rr, struct rdt_domain *d,
        rr->evtid = evtid;
        rr->d = d;
        rr->val = 0;
+       rr->first = first;
 
        smp_call_function_any(&d->cpu_mask, mon_event_count, rr, 1);
 }
@@ -325,7 +326,7 @@ int rdtgroup_mondata_show(struct seq_file *m, void *arg)
                goto out;
        }
 
-       mon_event_read(&rr, d, rdtgrp, evtid);
+       mon_event_read(&rr, d, rdtgrp, evtid, false);
 
        if (rr.val & RMID_VAL_ERROR)
                seq_puts(m, "Error\n");

diff --git a/arch/x86/kernel/cpu/intel_rdt_monitor.c b/arch/x86/kernel/cpu/intel_rdt_monitor.c
index ef0358b591022c990a7eba464cc379e69fcb06f1..383a023fca35198b6bddc75dc1a115d4dd7fa386 100644 (file)
--- a/arch/x86/kernel/cpu/intel_rdt_monitor.c
+++ b/arch/x86/kernel/cpu/intel_rdt_monitor.c
@@ -321,6 +321,13 @@ static int __mon_event_count(u32 rmid, struct rmid_read *rr)
                 */
                return -EINVAL;
        }
+
+       if (rr->first) {
+               m->prev_msr = tval;
+               m->chunks = 0;
+               return 0;
+       }
+
        shift = 64 - MBM_CNTR_WIDTH;
        chunks = (tval << shift) - (m->prev_msr << shift);
        chunks >>= shift;

diff --git a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
index ea37b972df4f9827ed79ddc895fb55f080532d7a..05088e301ef878092304d6e242252dc8271b04c1 100644 (file)
--- a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
+++ b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
@@ -1351,6 +1351,7 @@ static int mkdir_mondata_subdir(struct kernfs_node *parent_kn,
        union mon_data_bits priv;
        struct kernfs_node *kn;
        struct mon_evt *mevt;
+       struct rmid_read rr;
        char name[32];
        int ret;
 
@@ -1381,6 +1382,9 @@ static int mkdir_mondata_subdir(struct kernfs_node *parent_kn,
                ret = mon_addfile(kn, mevt->name, priv.priv);
                if (ret)
                        goto out_destroy;
+
+               if (is_mbm_event(mevt->evtid))
+                       mon_event_read(&rr, d, prgrp, mevt->evtid, true);
        }
        kernfs_activate(kn);
        return 0;