[PATCH 27/28] x86/intel_rdt/mbm: Add mbm counter initialization

From: Vikas Shivappa
Date: Tue Jul 25 2017 - 17:13:49 EST


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@xxxxxxxxxxxxxxx>
---
arch/x86/kernel/cpu/intel_rdt.h | 9 +++++++++
arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c | 5 +++--
arch/x86/kernel/cpu/intel_rdt_monitor.c | 7 +++++++
arch/x86/kernel/cpu/intel_rdt_rdtgroup.c | 4 ++++
4 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/cpu/intel_rdt.h b/arch/x86/kernel/cpu/intel_rdt.h
index 2137d5e..f160403 100644
--- 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 cf8e2c7..f6ea94f 100644
--- 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 ef0358b..383a023 100644
--- 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 90a22d3..50b5d03 100644
--- a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
+++ b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
@@ -1352,6 +1352,7 @@ 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;

@@ -1382,6 +1383,9 @@ 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;
--
1.9.1