2023-01-27 01:50:24

by Byungchul Park

[permalink] [raw]
Subject: [PATCH v8 06/25] dept: Add proc knobs to show stats and dependency graph

It'd be useful to show Dept internal stats and dependency graph on
runtime via proc for better information. Introduced the knobs.

Signed-off-by: Byungchul Park <[email protected]>
---
kernel/dependency/Makefile | 1 +
kernel/dependency/dept.c | 24 ++++------
kernel/dependency/dept_internal.h | 26 +++++++++++
kernel/dependency/dept_proc.c | 95 +++++++++++++++++++++++++++++++++++++++
4 files changed, 131 insertions(+), 15 deletions(-)
create mode 100644 kernel/dependency/dept_internal.h
create mode 100644 kernel/dependency/dept_proc.c

diff --git a/kernel/dependency/Makefile b/kernel/dependency/Makefile
index b5cfb8a..92f1654 100644
--- a/kernel/dependency/Makefile
+++ b/kernel/dependency/Makefile
@@ -1,3 +1,4 @@
# SPDX-License-Identifier: GPL-2.0

obj-$(CONFIG_DEPT) += dept.o
+obj-$(CONFIG_DEPT) += dept_proc.o
diff --git a/kernel/dependency/dept.c b/kernel/dependency/dept.c
index 72040c8..8e7e4af 100644
--- a/kernel/dependency/dept.c
+++ b/kernel/dependency/dept.c
@@ -73,6 +73,7 @@
#include <linux/hash.h>
#include <linux/dept.h>
#include <linux/utsname.h>
+#include "dept_internal.h"

static int dept_stop;
static int dept_per_cpu_ready;
@@ -260,20 +261,13 @@ static inline bool valid_key(struct dept_key *k)
* have been freed will be placed.
*/

-enum object_t {
-#define OBJECT(id, nr) OBJECT_##id,
- #include "dept_object.h"
-#undef OBJECT
- OBJECT_NR,
-};
-
#define OBJECT(id, nr) \
static struct dept_##id spool_##id[nr]; \
static DEFINE_PER_CPU(struct llist_head, lpool_##id);
#include "dept_object.h"
#undef OBJECT

-static struct dept_pool pool[OBJECT_NR] = {
+struct dept_pool dept_pool[OBJECT_NR] = {
#define OBJECT(id, nr) { \
.name = #id, \
.obj_sz = sizeof(struct dept_##id), \
@@ -303,7 +297,7 @@ static void *from_pool(enum object_t t)
if (DEPT_WARN_ON(!irqs_disabled()))
return NULL;

- p = &pool[t];
+ p = &dept_pool[t];

/*
* Try local pool first.
@@ -338,7 +332,7 @@ static void *from_pool(enum object_t t)

static void to_pool(void *o, enum object_t t)
{
- struct dept_pool *p = &pool[t];
+ struct dept_pool *p = &dept_pool[t];
struct llist_head *h;

preempt_disable();
@@ -2113,7 +2107,7 @@ void dept_map_copy(struct dept_map *to, struct dept_map *from)
clean_classes_cache(&to->map_key);
}

-static LIST_HEAD(classes);
+LIST_HEAD(dept_classes);

static inline bool within(const void *addr, void *start, unsigned long size)
{
@@ -2145,7 +2139,7 @@ void dept_free_range(void *start, unsigned int sz)
while (unlikely(!dept_lock()))
cpu_relax();

- list_for_each_entry_safe(c, n, &classes, all_node) {
+ list_for_each_entry_safe(c, n, &dept_classes, all_node) {
if (!within((void *)c->key, start, sz) &&
!within(c->name, start, sz))
continue;
@@ -2221,7 +2215,7 @@ static struct dept_class *check_new_class(struct dept_key *local,
c->sub_id = sub_id;
c->key = (unsigned long)(k->base + sub_id);
hash_add_class(c);
- list_add(&c->all_node, &classes);
+ list_add(&c->all_node, &dept_classes);
unlock:
dept_unlock();
caching:
@@ -2935,8 +2929,8 @@ static void migrate_per_cpu_pool(void)
struct llist_head *from;
struct llist_head *to;

- from = &pool[i].boot_pool;
- to = per_cpu_ptr(pool[i].lpool, boot_cpu);
+ from = &dept_pool[i].boot_pool;
+ to = per_cpu_ptr(dept_pool[i].lpool, boot_cpu);
move_llist(to, from);
}
}
diff --git a/kernel/dependency/dept_internal.h b/kernel/dependency/dept_internal.h
new file mode 100644
index 00000000..007c1ee
--- /dev/null
+++ b/kernel/dependency/dept_internal.h
@@ -0,0 +1,26 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Dept(DEPendency Tracker) - runtime dependency tracker internal header
+ *
+ * Started by Byungchul Park <[email protected]>:
+ *
+ * Copyright (c) 2020 LG Electronics, Inc., Byungchul Park
+ */
+
+#ifndef __DEPT_INTERNAL_H
+#define __DEPT_INTERNAL_H
+
+#ifdef CONFIG_DEPT
+
+enum object_t {
+#define OBJECT(id, nr) OBJECT_##id,
+ #include "dept_object.h"
+#undef OBJECT
+ OBJECT_NR,
+};
+
+extern struct list_head dept_classes;
+extern struct dept_pool dept_pool[];
+
+#endif
+#endif /* __DEPT_INTERNAL_H */
diff --git a/kernel/dependency/dept_proc.c b/kernel/dependency/dept_proc.c
new file mode 100644
index 00000000..7d61dfb
--- /dev/null
+++ b/kernel/dependency/dept_proc.c
@@ -0,0 +1,95 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Procfs knobs for Dept(DEPendency Tracker)
+ *
+ * Started by Byungchul Park <[email protected]>:
+ *
+ * Copyright (C) 2021 LG Electronics, Inc. , Byungchul Park
+ */
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/dept.h>
+#include "dept_internal.h"
+
+static void *l_next(struct seq_file *m, void *v, loff_t *pos)
+{
+ /*
+ * XXX: Serialize list traversal if needed. The following might
+ * give a wrong information on contention.
+ */
+ return seq_list_next(v, &dept_classes, pos);
+}
+
+static void *l_start(struct seq_file *m, loff_t *pos)
+{
+ /*
+ * XXX: Serialize list traversal if needed. The following might
+ * give a wrong information on contention.
+ */
+ return seq_list_start_head(&dept_classes, *pos);
+}
+
+static void l_stop(struct seq_file *m, void *v)
+{
+}
+
+static int l_show(struct seq_file *m, void *v)
+{
+ struct dept_class *fc = list_entry(v, struct dept_class, all_node);
+ struct dept_dep *d;
+ const char *prefix;
+
+ if (v == &dept_classes) {
+ seq_puts(m, "All classes:\n\n");
+ return 0;
+ }
+
+ prefix = fc->sched_map ? "<sched> " : "";
+ seq_printf(m, "[%p] %s%s\n", (void *)fc->key, prefix, fc->name);
+
+ /*
+ * XXX: Serialize list traversal if needed. The following might
+ * give a wrong information on contention.
+ */
+ list_for_each_entry(d, &fc->dep_head, dep_node) {
+ struct dept_class *tc = d->wait->class;
+
+ prefix = tc->sched_map ? "<sched> " : "";
+ seq_printf(m, " -> [%p] %s%s\n", (void *)tc->key, prefix, tc->name);
+ }
+ seq_puts(m, "\n");
+
+ return 0;
+}
+
+static const struct seq_operations dept_deps_ops = {
+ .start = l_start,
+ .next = l_next,
+ .stop = l_stop,
+ .show = l_show,
+};
+
+static int dept_stats_show(struct seq_file *m, void *v)
+{
+ int r;
+
+ seq_puts(m, "Availability in the static pools:\n\n");
+#define OBJECT(id, nr) \
+ r = atomic_read(&dept_pool[OBJECT_##id].obj_nr); \
+ if (r < 0) \
+ r = 0; \
+ seq_printf(m, "%s\t%d/%d(%d%%)\n", #id, r, nr, (r * 100) / (nr));
+ #include "dept_object.h"
+#undef OBJECT
+
+ return 0;
+}
+
+static int __init dept_proc_init(void)
+{
+ proc_create_seq("dept_deps", S_IRUSR, NULL, &dept_deps_ops);
+ proc_create_single("dept_stats", S_IRUSR, NULL, dept_stats_show);
+ return 0;
+}
+
+__initcall(dept_proc_init);
--
1.9.1