[tip:x86/cache] x86/intel_rdt/cqm: Add mon_data

From: tip-bot for Vikas Shivappa
Date: Tue Aug 01 2017 - 16:54:53 EST


Commit-ID: d89b7379015fc561060a4094676d143e6ed264e7
Gitweb: http://git.kernel.org/tip/d89b7379015fc561060a4094676d143e6ed264e7
Author: Vikas Shivappa <vikas.shivappa@xxxxxxxxxxxxxxx>
AuthorDate: Tue, 25 Jul 2017 14:14:38 -0700
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Tue, 1 Aug 2017 22:41:26 +0200

x86/intel_rdt/cqm: Add mon_data

Add a mon_data directory for the root rdtgroup and all other rdtgroups.
The directory holds all of the monitored data for all domains and events
of all resources being monitored.

The mon_data itself has a list of directories in the format
mon_<domain_name>_<domain_id>. Each of these subdirectories contain one
file per event in the mode "0444". Reading the file displays a snapshot
of the monitored data for the event the file represents.

For ex, on a 2 socket Broadwell with llc_occupancy being
monitored the mon_data contents look as below:

$ ls /sys/fs/resctrl/p1/mon_data/
mon_L3_00
mon_L3_01

Each domain directory has one file per event:
$ ls /sys/fs/resctrl/p1/mon_data/mon_L3_00/
llc_occupancy

To read current llc_occupancy of ctrl_mon group p1
$ cat /sys/fs/resctrl/p1/mon_data/mon_L3_00/llc_occupancy
33789096

[This patch idea is based on Tony's sample patches to organise data in a
per domain directory and have one file per event (and use the fp->priv to
store mon data bits)]

Signed-off-by: Vikas Shivappa <vikas.shivappa@xxxxxxxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: ravi.v.shankar@xxxxxxxxx
Cc: tony.luck@xxxxxxxxx
Cc: fenghua.yu@xxxxxxxxx
Cc: peterz@xxxxxxxxxxxxx
Cc: eranian@xxxxxxxxxx
Cc: vikas.shivappa@xxxxxxxxx
Cc: ak@xxxxxxxxxxxxxxx
Cc: davidcc@xxxxxxxxxx
Cc: reinette.chatre@xxxxxxxxx
Link: http://lkml.kernel.org/r/1501017287-28083-20-git-send-email-vikas.shivappa@xxxxxxxxxxxxxxx

---
arch/x86/kernel/cpu/intel_rdt.c | 9 +-
arch/x86/kernel/cpu/intel_rdt.h | 29 ++++++
arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c | 55 ++++++++++-
arch/x86/kernel/cpu/intel_rdt_monitor.c | 49 ++++++++++
arch/x86/kernel/cpu/intel_rdt_rdtgroup.c | 145 ++++++++++++++++++++++++++++
5 files changed, 284 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kernel/cpu/intel_rdt.c b/arch/x86/kernel/cpu/intel_rdt.c
index 303b085..050ea15 100644
--- a/arch/x86/kernel/cpu/intel_rdt.c
+++ b/arch/x86/kernel/cpu/intel_rdt.c
@@ -71,6 +71,7 @@ cat_wrmsr(struct rdt_domain *d, struct msr_param *m, struct rdt_resource *r);
struct rdt_resource rdt_resources_all[] = {
[RDT_RESOURCE_L3] =
{
+ .rid = RDT_RESOURCE_L3,
.name = "L3",
.domains = domain_init(RDT_RESOURCE_L3),
.msr_base = IA32_L3_CBM_BASE,
@@ -87,6 +88,7 @@ struct rdt_resource rdt_resources_all[] = {
},
[RDT_RESOURCE_L3DATA] =
{
+ .rid = RDT_RESOURCE_L3DATA,
.name = "L3DATA",
.domains = domain_init(RDT_RESOURCE_L3DATA),
.msr_base = IA32_L3_CBM_BASE,
@@ -103,6 +105,7 @@ struct rdt_resource rdt_resources_all[] = {
},
[RDT_RESOURCE_L3CODE] =
{
+ .rid = RDT_RESOURCE_L3CODE,
.name = "L3CODE",
.domains = domain_init(RDT_RESOURCE_L3CODE),
.msr_base = IA32_L3_CBM_BASE,
@@ -119,6 +122,7 @@ struct rdt_resource rdt_resources_all[] = {
},
[RDT_RESOURCE_L2] =
{
+ .rid = RDT_RESOURCE_L2,
.name = "L2",
.domains = domain_init(RDT_RESOURCE_L2),
.msr_base = IA32_L2_CBM_BASE,
@@ -135,6 +139,7 @@ struct rdt_resource rdt_resources_all[] = {
},
[RDT_RESOURCE_MBA] =
{
+ .rid = RDT_RESOURCE_MBA,
.name = "MB",
.domains = domain_init(RDT_RESOURCE_MBA),
.msr_base = IA32_MBA_THRTL_BASE,
@@ -362,8 +367,8 @@ void rdt_ctrl_update(void *arg)
* caller, return the first domain whose id is bigger than the input id.
* The domain list is sorted by id in ascending order.
*/
-static struct rdt_domain *rdt_find_domain(struct rdt_resource *r, int id,
- struct list_head **pos)
+struct rdt_domain *rdt_find_domain(struct rdt_resource *r, int id,
+ struct list_head **pos)
{
struct rdt_domain *d;
struct list_head *l;
diff --git a/arch/x86/kernel/cpu/intel_rdt.h b/arch/x86/kernel/cpu/intel_rdt.h
index 6f07047..7fcaa5f 100644
--- a/arch/x86/kernel/cpu/intel_rdt.h
+++ b/arch/x86/kernel/cpu/intel_rdt.h
@@ -33,6 +33,27 @@ struct mon_evt {
struct list_head list;
};

+/**
+ * struct mon_data_bits - Monitoring details for each event file
+ * @rid: Resource id associated with the event file.
+ * @evtid: Event id associated with the event file
+ * @domid: The domain to which the event file belongs
+ */
+union mon_data_bits {
+ void *priv;
+ struct {
+ unsigned int rid : 10;
+ unsigned int evtid : 8;
+ unsigned int domid : 14;
+ } u;
+};
+
+struct rmid_read {
+ struct rdtgroup *rgrp;
+ int evtid;
+ u64 val;
+};
+
extern unsigned int intel_cqm_threshold;
extern bool rdt_alloc_capable;
extern bool rdt_mon_capable;
@@ -46,11 +67,13 @@ enum rdt_group_type {

/**
* struct mongroup - store mon group's data in resctrl fs.
+ * @mon_data_kn kernlfs node for the mon_data directory
* @parent: parent rdtgrp
* @crdtgrp_list: child rdtgroup node list
* @rmid: rmid for this rdtgroup
*/
struct mongroup {
+ struct kernfs_node *mon_data_kn;
struct rdtgroup *parent;
struct list_head crdtgrp_list;
u32 rmid;
@@ -209,6 +232,7 @@ static inline bool is_llc_occupancy_enabled(void)

/**
* struct rdt_resource - attributes of an RDT resource
+ * @rid: The index of the resource
* @alloc_enabled: Is allocation enabled on this machine
* @mon_enabled: Is monitoring enabled for this feature
* @alloc_capable: Is allocation available on this machine
@@ -230,6 +254,7 @@ static inline bool is_llc_occupancy_enabled(void)
* @fflags: flags to choose base and info files
*/
struct rdt_resource {
+ int rid;
bool alloc_enabled;
bool mon_enabled;
bool alloc_capable;
@@ -323,6 +348,8 @@ union cpuid_0x10_x_edx {
void rdt_ctrl_update(void *arg);
struct rdtgroup *rdtgroup_kn_lock_live(struct kernfs_node *kn);
void rdtgroup_kn_unlock(struct kernfs_node *kn);
+struct rdt_domain *rdt_find_domain(struct rdt_resource *r, int id,
+ struct list_head **pos);
ssize_t rdtgroup_schemata_write(struct kernfs_open_file *of,
char *buf, size_t nbytes, loff_t off);
int rdtgroup_schemata_show(struct kernfs_open_file *of,
@@ -331,5 +358,7 @@ struct rdt_domain *get_domain_from_cpu(int cpu, struct rdt_resource *r);
int alloc_rmid(void);
void free_rmid(u32 rmid);
int rdt_get_mon_l3_config(struct rdt_resource *r);
+void mon_event_count(void *info);
+int rdtgroup_mondata_show(struct seq_file *m, void *arg);

#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 952156c..f44e77d 100644
--- a/arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c
+++ b/arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c
@@ -269,7 +269,8 @@ int rdtgroup_schemata_show(struct kernfs_open_file *of,
{
struct rdtgroup *rdtgrp;
struct rdt_resource *r;
- int closid, ret = 0;
+ int ret = 0;
+ u32 closid;

rdtgrp = rdtgroup_kn_lock_live(of->kn);
if (rdtgrp) {
@@ -284,3 +285,55 @@ int rdtgroup_schemata_show(struct kernfs_open_file *of,
rdtgroup_kn_unlock(of->kn);
return ret;
}
+
+void mon_event_read(struct rmid_read *rr, struct rdt_domain *d,
+ struct rdtgroup *rdtgrp, int evtid)
+{
+ /*
+ * setup the parameters to send to the IPI to read the data.
+ */
+ rr->rgrp = rdtgrp;
+ rr->evtid = evtid;
+ rr->val = 0;
+
+ smp_call_function_any(&d->cpu_mask, mon_event_count, rr, 1);
+}
+
+int rdtgroup_mondata_show(struct seq_file *m, void *arg)
+{
+ struct kernfs_open_file *of = m->private;
+ u32 resid, evtid, domid;
+ struct rdtgroup *rdtgrp;
+ struct rdt_resource *r;
+ union mon_data_bits md;
+ struct rdt_domain *d;
+ struct rmid_read rr;
+ int ret = 0;
+
+ rdtgrp = rdtgroup_kn_lock_live(of->kn);
+
+ md.priv = of->kn->priv;
+ resid = md.u.rid;
+ domid = md.u.domid;
+ evtid = md.u.evtid;
+
+ r = &rdt_resources_all[resid];
+ d = rdt_find_domain(r, domid, NULL);
+ if (!d) {
+ ret = -ENOENT;
+ goto out;
+ }
+
+ mon_event_read(&rr, d, rdtgrp, evtid);
+
+ if (rr.val & RMID_VAL_ERROR)
+ seq_puts(m, "Error\n");
+ else if (rr.val & RMID_VAL_UNAVAIL)
+ seq_puts(m, "Unavailable\n");
+ else
+ seq_printf(m, "%llu\n", rr.val * r->mon_scale);
+
+out:
+ rdtgroup_kn_unlock(of->kn);
+ return ret;
+}
diff --git a/arch/x86/kernel/cpu/intel_rdt_monitor.c b/arch/x86/kernel/cpu/intel_rdt_monitor.c
index b6732c5..f8f06f5 100644
--- a/arch/x86/kernel/cpu/intel_rdt_monitor.c
+++ b/arch/x86/kernel/cpu/intel_rdt_monitor.c
@@ -294,6 +294,55 @@ void free_rmid(u32 rmid)
list_add_tail(&entry->list, &rmid_free_lru);
}

+static int __mon_event_count(u32 rmid, struct rmid_read *rr)
+{
+ u64 tval;
+
+ tval = __rmid_read(rmid, rr->evtid);
+ if (tval & (RMID_VAL_ERROR | RMID_VAL_UNAVAIL)) {
+ rr->val = tval;
+ return -EINVAL;
+ }
+ switch (rr->evtid) {
+ case QOS_L3_OCCUP_EVENT_ID:
+ rr->val += tval;
+ return 0;
+ default:
+ /*
+ * Code would never reach here because
+ * an invalid event id would fail the __rmid_read.
+ */
+ return -EINVAL;
+ }
+}
+
+/*
+ * This is called via IPI to read the CQM/MBM counters
+ * on a domain.
+ */
+void mon_event_count(void *info)
+{
+ struct rdtgroup *rdtgrp, *entry;
+ struct rmid_read *rr = info;
+ struct list_head *head;
+
+ rdtgrp = rr->rgrp;
+
+ if (__mon_event_count(rdtgrp->mon.rmid, rr))
+ return;
+
+ /*
+ * For Ctrl groups read data from child monitor groups.
+ */
+ head = &rdtgrp->mon.crdtgrp_list;
+
+ if (rdtgrp->type == RDTCTRL_GROUP) {
+ list_for_each_entry(entry, head, mon.crdtgrp_list) {
+ if (__mon_event_count(entry->mon.rmid, rr))
+ return;
+ }
+ }
+}
static int dom_data_init(struct rdt_resource *r)
{
struct rmid_entry *entry = NULL;
diff --git a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
index 89457bb..59de36d 100644
--- a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
+++ b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
@@ -152,6 +152,11 @@ static struct kernfs_ops rdtgroup_kf_single_ops = {
.seq_show = rdtgroup_seqfile_show,
};

+static struct kernfs_ops kf_mondata_ops = {
+ .atomic_write_len = PAGE_SIZE,
+ .seq_show = rdtgroup_mondata_show,
+};
+
static bool is_cpu_list(struct kernfs_open_file *of)
{
struct rftype *rft = of->kn->priv;
@@ -1217,6 +1222,140 @@ static struct file_system_type rdt_fs_type = {
.kill_sb = rdt_kill_sb,
};

+static int mon_addfile(struct kernfs_node *parent_kn, const char *name,
+ void *priv)
+{
+ struct kernfs_node *kn;
+ int ret = 0;
+
+ kn = __kernfs_create_file(parent_kn, name, 0444, 0,
+ &kf_mondata_ops, priv, NULL, NULL);
+ if (IS_ERR(kn))
+ return PTR_ERR(kn);
+
+ ret = rdtgroup_kn_set_ugid(kn);
+ if (ret) {
+ kernfs_remove(kn);
+ return ret;
+ }
+
+ return ret;
+}
+
+static int mkdir_mondata_subdir(struct kernfs_node *parent_kn,
+ struct rdt_domain *d,
+ struct rdt_resource *r, struct rdtgroup *prgrp)
+{
+ union mon_data_bits priv;
+ struct kernfs_node *kn;
+ struct mon_evt *mevt;
+ char name[32];
+ int ret;
+
+ sprintf(name, "mon_%s_%02d", r->name, d->id);
+ /* create the directory */
+ kn = kernfs_create_dir(parent_kn, name, parent_kn->mode, prgrp);
+ if (IS_ERR(kn))
+ return PTR_ERR(kn);
+
+ /*
+ * This extra ref will be put in kernfs_remove() and guarantees
+ * that kn is always accessible.
+ */
+ kernfs_get(kn);
+ ret = rdtgroup_kn_set_ugid(kn);
+ if (ret)
+ goto out_destroy;
+
+ if (WARN_ON(list_empty(&r->evt_list))) {
+ ret = -EPERM;
+ goto out_destroy;
+ }
+
+ priv.u.rid = r->rid;
+ priv.u.domid = d->id;
+ list_for_each_entry(mevt, &r->evt_list, list) {
+ priv.u.evtid = mevt->evtid;
+ ret = mon_addfile(kn, mevt->name, priv.priv);
+ if (ret)
+ goto out_destroy;
+ }
+ kernfs_activate(kn);
+ return 0;
+
+out_destroy:
+ kernfs_remove(kn);
+ return ret;
+}
+
+static int mkdir_mondata_subdir_alldom(struct kernfs_node *parent_kn,
+ struct rdt_resource *r,
+ struct rdtgroup *prgrp)
+{
+ struct rdt_domain *dom;
+ int ret;
+
+ list_for_each_entry(dom, &r->domains, list) {
+ ret = mkdir_mondata_subdir(parent_kn, dom, r, prgrp);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+/*
+ * This creates a directory mon_data which contains the monitored data.
+ *
+ * mon_data has one directory for each domain whic are named
+ * in the format mon_<domain_name>_<domain_id>. For ex: A mon_data
+ * with L3 domain looks as below:
+ * ./mon_data:
+ * mon_L3_00
+ * mon_L3_01
+ * mon_L3_02
+ * ...
+ *
+ * Each domain directory has one file per event:
+ * ./mon_L3_00/:
+ * llc_occupancy
+ *
+ */
+static int mkdir_mondata_all(struct kernfs_node *parent_kn,
+ struct rdtgroup *prgrp,
+ struct kernfs_node **dest_kn)
+{
+ struct rdt_resource *r;
+ struct kernfs_node *kn;
+ int ret;
+
+ /*
+ * Create the mon_data directory first.
+ */
+ ret = mongroup_create_dir(parent_kn, NULL, "mon_data", &kn);
+ if (ret)
+ return ret;
+
+ if (dest_kn)
+ *dest_kn = kn;
+
+ /*
+ * Create the subdirectories for each domain. Note that all events
+ * in a domain like L3 are grouped into a resource whose domain is L3
+ */
+ for_each_mon_enabled_rdt_resource(r) {
+ ret = mkdir_mondata_subdir_alldom(kn, r, prgrp);
+ if (ret)
+ goto out_destroy;
+ }
+
+ return 0;
+
+out_destroy:
+ kernfs_remove(kn);
+ return ret;
+}
+
static int mkdir_rdt_prepare(struct kernfs_node *parent_kn,
struct kernfs_node *prgrp_kn,
const char *name, umode_t mode,
@@ -1275,6 +1414,10 @@ static int mkdir_rdt_prepare(struct kernfs_node *parent_kn,
if (ret < 0)
goto out_destroy;
rdtgrp->mon.rmid = ret;
+
+ ret = mkdir_mondata_all(kn, rdtgrp, &rdtgrp->mon.mon_data_kn);
+ if (ret)
+ goto out_idfree;
}
kernfs_activate(kn);

@@ -1283,6 +1426,8 @@ static int mkdir_rdt_prepare(struct kernfs_node *parent_kn,
*/
return 0;

+out_idfree:
+ free_rmid(rdtgrp->mon.rmid);
out_destroy:
kernfs_remove(rdtgrp->kn);
out_free_rgrp: