[PATCH v1 01/14] fs/resctrl: group the resource control types for schemata list

From: Amit Singh Tomar
Date: Wed Jan 17 2024 - 09:14:54 EST


At the moment, resource control group support the basic control features
(that can be applied to system resources like cache, and Memory)
such as CAT (Cache Allocation Technology), and MBA (Memory Bandwidth
Allocation).

Apart from these basic controls, System can support other controls that
does not directly affect the allocation of memory-system resources.
Instead, it has an effect on conflicts that arise during access to
resources, such as Priority partitioning found on ARM MPAM.

In order to support control types of different nature, lets divide them
into different groups, already existing control features (CAT, and MBA)
is grouped under basic schemata type .i.e. SCHEMATA_BASIC, and to support
priority partition (the downstream priority one), it is placed under
SCHEMA_DSPRI control type. These control type is associated with list(s)
of schemata.

Signed-off-by: Amit Singh Tomar <amitsinght@xxxxxxxxxxx>
---
Changes since RFC:
* No change, it's new patch.
---
fs/resctrl/rdtgroup.c | 26 ++++++++++++++++----------
include/linux/resctrl.h | 1 +
include/linux/resctrl_types.h | 6 ++++++
3 files changed, 23 insertions(+), 10 deletions(-)

diff --git a/fs/resctrl/rdtgroup.c b/fs/resctrl/rdtgroup.c
index 9c5dfaaa7fa2..12e31d4dddf6 100644
--- a/fs/resctrl/rdtgroup.c
+++ b/fs/resctrl/rdtgroup.c
@@ -2256,7 +2256,9 @@ static int rdt_enable_ctx(struct rdt_fs_context *ctx)
return ret;
}

-static int schemata_list_add(struct rdt_resource *r, enum resctrl_conf_type type)
+static int schemata_list_add(struct rdt_resource *r,
+ enum resctrl_conf_type type,
+ enum resctrl_ctrl_type ctrl_type)
{
struct resctrl_schema *s;
const char *suffix = "";
@@ -2284,10 +2286,12 @@ static int schemata_list_add(struct rdt_resource *r, enum resctrl_conf_type type
break;
}

- ret = snprintf(s->name, sizeof(s->name), "%s%s", r->name, suffix);
- if (ret >= sizeof(s->name)) {
- kfree(s);
- return -EINVAL;
+ if (ctrl_type == SCHEMA_BASIC) {
+ ret = snprintf(s->name, sizeof(s->name), "%s%s", r->name, suffix);
+ if (ret >= sizeof(s->name)) {
+ kfree(s);
+ return -EINVAL;
+ }
}

cl = strlen(s->name);
@@ -2300,14 +2304,15 @@ static int schemata_list_add(struct rdt_resource *r, enum resctrl_conf_type type
if (r->cdp_capable && !resctrl_arch_get_cdp_enabled(r->rid))
cl += 4;

- if (cl > max_name_width)
+ if (cl > max_name_width && ctrl_type == SCHEMA_BASIC)
max_name_width = cl;

/*
* Choose a width for the resource data based on the resource that has
* widest cbm/data_width.
*/
- max_data_width = max(max_data_width, r->data_width);
+ if (ctrl_type == SCHEMA_BASIC)
+ max_data_width = max(max_data_width, r->data_width);

INIT_LIST_HEAD(&s->list);
list_add(&s->list, &resctrl_schema_all);
@@ -2328,17 +2333,18 @@ static int schemata_list_create(void)
continue;

if (resctrl_arch_get_cdp_enabled(r->rid)) {
- ret = schemata_list_add(r, CDP_CODE);
+ ret = schemata_list_add(r, CDP_CODE, SCHEMA_BASIC);
if (ret)
break;

- ret = schemata_list_add(r, CDP_DATA);
+ ret = schemata_list_add(r, CDP_DATA, SCHEMA_BASIC);
} else {
- ret = schemata_list_add(r, CDP_NONE);
+ ret = schemata_list_add(r, CDP_NONE, SCHEMA_BASIC);
}

if (ret)
break;
+
}

return ret;
diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h
index 3ad308e9e226..125c4b0c2ff7 100644
--- a/include/linux/resctrl.h
+++ b/include/linux/resctrl.h
@@ -249,6 +249,7 @@ struct resctrl_schema {
struct list_head list;
char name[8];
enum resctrl_conf_type conf_type;
+ enum resctrl_ctrl_type ctrl_type;
struct rdt_resource *res;
u32 num_closid;
};
diff --git a/include/linux/resctrl_types.h b/include/linux/resctrl_types.h
index 3897de9c4ecb..b9268ec3ba71 100644
--- a/include/linux/resctrl_types.h
+++ b/include/linux/resctrl_types.h
@@ -57,6 +57,12 @@ enum resctrl_res_level {
RDT_NUM_RESOURCES,
};

+enum resctrl_ctrl_type {
+ SCHEMA_BASIC = 0,
+ SCHEMA_DSPRI,
+ SCHEMA_NUM_CTRL_TYPE
+};
+
#define CDP_NUM_TYPES (CDP_DATA + 1)

/*
--
2.25.1