@@ -56,7 +56,7 @@ struct rv_monitor {
bool rv_monitoring_on(void);
int rv_unregister_monitor(struct rv_monitor *monitor);
-int rv_register_monitor(struct rv_monitor *monitor);
+int rv_register_monitor(struct rv_monitor *monitor, struct rv_monitor *parent);
int rv_get_task_monitor_slot(void);
void rv_put_task_monitor_slot(int slot);
@@ -27,6 +27,7 @@ menuconfig RV
source "kernel/trace/rv/monitors/wip/Kconfig"
source "kernel/trace/rv/monitors/wwnr/Kconfig"
+source "kernel/trace/rv/monitors/sched/Kconfig"
# Add new monitors here
config RV_REACTORS
@@ -5,6 +5,7 @@ ccflags-y += -I $(src) # needed for trace events
obj-$(CONFIG_RV) += rv.o
obj-$(CONFIG_RV_MON_WIP) += monitors/wip/wip.o
obj-$(CONFIG_RV_MON_WWNR) += monitors/wwnr/wwnr.o
+obj-$(CONFIG_RV_MON_SCHED) += monitors/sched/sched.o
# Add new monitors here
obj-$(CONFIG_RV_REACTORS) += rv_reactors.o
obj-$(CONFIG_RV_REACT_PRINTK) += reactor_printk.o
new file mode 100644
@@ -0,0 +1,12 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+config RV_MON_SCHED
+ depends on RV
+ select DA_MON_EVENTS_IMPLICIT
+ bool "sched monitor"
+ help
+ Collection of monitors to check the scheduler behaves according to specifications.
+ Enable this to enable all scheduler specification supported by the current kernel.
+
+ For further information, see:
+ Documentation/trace/rv/monitor_sched.rst
new file mode 100644
@@ -0,0 +1,38 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/rv.h>
+
+#define MODULE_NAME "sched"
+
+#include "sched.h"
+
+struct rv_monitor rv_sched;
+
+struct rv_monitor rv_sched = {
+ .name = "sched",
+ .description = "container for several scheduler monitor specifications.",
+ .enable = NULL,
+ .disable = NULL,
+ .reset = NULL,
+ .enabled = 0,
+};
+
+static int __init register_sched(void)
+{
+ rv_register_monitor(&rv_sched, NULL);
+ return 0;
+}
+
+static void __exit unregister_sched(void)
+{
+ rv_unregister_monitor(&rv_sched);
+}
+
+module_init(register_sched);
+module_exit(unregister_sched);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Gabriele Monaco <gmonaco@redhat.com>");
+MODULE_DESCRIPTION("sched: container for several scheduler monitor specifications.");
new file mode 100644
@@ -0,0 +1,3 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+extern struct rv_monitor rv_sched;
@@ -71,7 +71,7 @@ static struct rv_monitor rv_wip = {
static int __init register_wip(void)
{
- rv_register_monitor(&rv_wip);
+ rv_register_monitor(&rv_wip, NULL);
return 0;
}
@@ -70,7 +70,7 @@ static struct rv_monitor rv_wwnr = {
static int __init register_wwnr(void)
{
- rv_register_monitor(&rv_wwnr);
+ rv_register_monitor(&rv_wwnr, NULL);
return 0;
}
@@ -162,7 +162,7 @@ struct dentry *get_monitors_root(void)
/*
* Interface for the monitor register.
*/
-static LIST_HEAD(rv_monitors_list);
+LIST_HEAD(rv_monitors_list);
static int task_monitor_count;
static bool task_monitor_slots[RV_PER_TASK_MONITORS];
@@ -206,6 +206,28 @@ void rv_put_task_monitor_slot(int slot)
task_monitor_slots[slot] = false;
}
+/*
+ * Monitors with a parent are nested,
+ * Monitors without a parent could be standalone or containers.
+ */
+bool rv_is_nested_monitor(struct rv_monitor_def *mdef)
+{
+ return mdef->parent != NULL;
+}
+
+/*
+ * We set our list to have nested monitors listed after their parent
+ * if a monitor has a child element its a container.
+ * This function would return false for empty containers but we should
+ * not allow them anyway.
+ */
+bool rv_is_container_monitor(struct rv_monitor_def *mdef)
+{
+ struct rv_monitor_def *next = list_next_entry(mdef, list);
+
+ return next->parent == mdef->monitor;
+}
+
/*
* This section collects the monitor/ files and folders.
*/
@@ -229,7 +251,8 @@ static int __rv_disable_monitor(struct rv_monitor_def *mdef, bool sync)
if (mdef->monitor->enabled) {
mdef->monitor->enabled = 0;
- mdef->monitor->disable();
+ if (mdef->monitor->disable)
+ mdef->monitor->disable();
/*
* Wait for the execution of all events to finish.
@@ -243,6 +266,60 @@ static int __rv_disable_monitor(struct rv_monitor_def *mdef, bool sync)
return 0;
}
+static void rv_disable_single(struct rv_monitor_def *mdef)
+{
+ __rv_disable_monitor(mdef, true);
+}
+
+static int rv_enable_single(struct rv_monitor_def *mdef)
+{
+ int retval;
+
+ lockdep_assert_held(&rv_interface_lock);
+
+ if (mdef->monitor->enabled)
+ return 0;
+
+ retval = mdef->monitor->enable();
+
+ if (!retval)
+ mdef->monitor->enabled = 1;
+
+ return retval;
+}
+
+static void rv_disable_container(struct rv_monitor_def *mdef)
+{
+ struct rv_monitor_def *p = mdef;
+ int enabled = 0;
+
+ list_for_each_entry_continue(p, &rv_monitors_list, list) {
+ if (p->parent != mdef->monitor)
+ break;
+ enabled += __rv_disable_monitor(p, false);
+ }
+ if (enabled)
+ tracepoint_synchronize_unregister();
+ mdef->monitor->enabled = 0;
+}
+
+static int rv_enable_container(struct rv_monitor_def *mdef)
+{
+ struct rv_monitor_def *p = mdef;
+ int retval = 0;
+
+ list_for_each_entry_continue(p, &rv_monitors_list, list) {
+ if (retval || p->parent != mdef->monitor)
+ break;
+ retval = rv_enable_single(p);
+ }
+ if (retval)
+ rv_disable_container(mdef);
+ else
+ mdef->monitor->enabled = 1;
+ return retval;
+}
+
/**
* rv_disable_monitor - disable a given runtime monitor
* @mdef: Pointer to the monitor definition structure.
@@ -251,7 +328,11 @@ static int __rv_disable_monitor(struct rv_monitor_def *mdef, bool sync)
*/
int rv_disable_monitor(struct rv_monitor_def *mdef)
{
- __rv_disable_monitor(mdef, true);
+ if (rv_is_container_monitor(mdef))
+ rv_disable_container(mdef);
+ else
+ rv_disable_single(mdef);
+
return 0;
}
@@ -265,15 +346,10 @@ int rv_enable_monitor(struct rv_monitor_def *mdef)
{
int retval;
- lockdep_assert_held(&rv_interface_lock);
-
- if (mdef->monitor->enabled)
- return 0;
-
- retval = mdef->monitor->enable();
-
- if (!retval)
- mdef->monitor->enabled = 1;
+ if (rv_is_container_monitor(mdef))
+ retval = rv_enable_container(mdef);
+ else
+ retval = rv_enable_single(mdef);
return retval;
}
@@ -336,9 +412,9 @@ static const struct file_operations interface_desc_fops = {
* the monitor dir, where the specific options of the monitor
* are exposed.
*/
-static int create_monitor_dir(struct rv_monitor_def *mdef)
+static int create_monitor_dir(struct rv_monitor_def *mdef, struct rv_monitor_def *parent)
{
- struct dentry *root = get_monitors_root();
+ struct dentry *root = parent ? parent->root_d : get_monitors_root();
const char *name = mdef->monitor->name;
struct dentry *tmp;
int retval;
@@ -377,7 +453,11 @@ static int monitors_show(struct seq_file *m, void *p)
{
struct rv_monitor_def *mon_def = p;
- seq_printf(m, "%s\n", mon_def->monitor->name);
+ if (mon_def->parent)
+ seq_printf(m, "%s:%s\n", mon_def->parent->name,
+ mon_def->monitor->name);
+ else
+ seq_printf(m, "%s\n", mon_def->monitor->name);
return 0;
}
@@ -514,7 +594,7 @@ static ssize_t enabled_monitors_write(struct file *filp, const char __user *user
struct rv_monitor_def *mdef;
int retval = -EINVAL;
bool enable = true;
- char *ptr;
+ char *ptr, *tmp;
int len;
if (count < 1 || count > MAX_RV_MONITOR_NAME_SIZE + 1)
@@ -541,6 +621,11 @@ static ssize_t enabled_monitors_write(struct file *filp, const char __user *user
retval = -EINVAL;
+ /* we support 1 nesting level, trim the parent */
+ tmp = strstr(ptr, ":");
+ if (tmp)
+ ptr = tmp+1;
+
list_for_each_entry(mdef, &rv_monitors_list, list) {
if (strcmp(ptr, mdef->monitor->name) != 0)
continue;
@@ -613,7 +698,7 @@ static void reset_all_monitors(void)
struct rv_monitor_def *mdef;
list_for_each_entry(mdef, &rv_monitors_list, list) {
- if (mdef->monitor->enabled)
+ if (mdef->monitor->enabled && mdef->monitor->reset)
mdef->monitor->reset();
}
}
@@ -688,15 +773,15 @@ static void destroy_monitor_dir(struct rv_monitor_def *mdef)
*
* Returns 0 if successful, error otherwise.
*/
-int rv_register_monitor(struct rv_monitor *monitor)
+int rv_register_monitor(struct rv_monitor *monitor, struct rv_monitor *parent)
{
- struct rv_monitor_def *r;
+ struct rv_monitor_def *r, *p = NULL;
int retval = 0;
if (strlen(monitor->name) >= MAX_RV_MONITOR_NAME_SIZE) {
pr_info("Monitor %s has a name longer than %d\n", monitor->name,
MAX_RV_MONITOR_NAME_SIZE);
- return -1;
+ return -EINVAL;
}
mutex_lock(&rv_interface_lock);
@@ -704,11 +789,26 @@ int rv_register_monitor(struct rv_monitor *monitor)
list_for_each_entry(r, &rv_monitors_list, list) {
if (strcmp(monitor->name, r->monitor->name) == 0) {
pr_info("Monitor %s is already registered\n", monitor->name);
- retval = -1;
+ retval = -EEXIST;
goto out_unlock;
}
}
+ if (parent) {
+ list_for_each_entry(r, &rv_monitors_list, list) {
+ if (strcmp(parent->name, r->monitor->name) == 0) {
+ p = r;
+ break;
+ }
+ }
+ }
+
+ if (p && rv_is_nested_monitor(p)) {
+ pr_info("Parent monitor %s is already nested, cannot nest further\n",
+ parent->name);
+ return -EINVAL;
+ }
+
r = kzalloc(sizeof(struct rv_monitor_def), GFP_KERNEL);
if (!r) {
retval = -ENOMEM;
@@ -716,14 +816,19 @@ int rv_register_monitor(struct rv_monitor *monitor)
}
r->monitor = monitor;
+ r->parent = parent;
- retval = create_monitor_dir(r);
+ retval = create_monitor_dir(r, p);
if (retval) {
kfree(r);
goto out_unlock;
}
- list_add_tail(&r->list, &rv_monitors_list);
+ /* keep children close to the parent for easier visualisation */
+ if (p)
+ list_add(&r->list, &p->list);
+ else
+ list_add_tail(&r->list, &rv_monitors_list);
out_unlock:
mutex_unlock(&rv_interface_lock);
@@ -21,6 +21,7 @@ struct rv_interface {
#define MAX_RV_REACTOR_NAME_SIZE 32
extern struct mutex rv_interface_lock;
+extern struct list_head rv_monitors_list;
#ifdef CONFIG_RV_REACTORS
struct rv_reactor_def {
@@ -34,6 +35,7 @@ struct rv_reactor_def {
struct rv_monitor_def {
struct list_head list;
struct rv_monitor *monitor;
+ struct rv_monitor *parent;
struct dentry *root_d;
#ifdef CONFIG_RV_REACTORS
struct rv_reactor_def *rdef;
@@ -45,6 +47,8 @@ struct rv_monitor_def {
struct dentry *get_monitors_root(void);
int rv_disable_monitor(struct rv_monitor_def *mdef);
int rv_enable_monitor(struct rv_monitor_def *mdef);
+bool rv_is_container_monitor(struct rv_monitor_def *mdef);
+bool rv_is_nested_monitor(struct rv_monitor_def *mdef);
#ifdef CONFIG_RV_REACTORS
int reactor_populate_monitor(struct rv_monitor_def *mdef);
@@ -158,8 +158,9 @@ static const struct seq_operations monitor_reactors_seq_ops = {
.show = monitor_reactor_show
};
-static void monitor_swap_reactors(struct rv_monitor_def *mdef, struct rv_reactor_def *rdef,
- bool reacting)
+static void monitor_swap_reactors_single(struct rv_monitor_def *mdef,
+ struct rv_reactor_def *rdef,
+ bool reacting, bool nested)
{
bool monitor_enabled;
@@ -179,10 +180,31 @@ static void monitor_swap_reactors(struct rv_monitor_def *mdef, struct rv_reactor
mdef->reacting = reacting;
mdef->monitor->react = rdef->reactor->react;
- if (monitor_enabled)
+ /* enable only once if iterating through a container */
+ if (monitor_enabled && !nested)
rv_enable_monitor(mdef);
}
+static void monitor_swap_reactors(struct rv_monitor_def *mdef,
+ struct rv_reactor_def *rdef, bool reacting)
+{
+ struct rv_monitor_def *p = mdef;
+
+ if (rv_is_container_monitor(mdef))
+ list_for_each_entry_continue(p, &rv_monitors_list, list) {
+ if (p->parent != mdef->monitor)
+ break;
+ monitor_swap_reactors_single(p, rdef, reacting, true);
+ }
+ /*
+ * This call enables and disables the monitor if they were active.
+ * In case of a container, we already disabled all and will enable all.
+ * All nested monitors are enabled also if they were off, we may refine
+ * this logic in the future.
+ */
+ monitor_swap_reactors_single(mdef, rdef, reacting, false);
+}
+
static ssize_t
monitor_reactors_write(struct file *file, const char __user *user_buf,
size_t count, loff_t *ppos)
Monitors describing complex systems, such as the scheduler, can easily grow to the point where they are just hard to understand because of the many possible state transitions. Often it is possible to break such descriptions into smaller monitors, sharing some or all events. Enabling those smaller monitors concurrently is, in fact, testing the system as if we had one single larger monitor. Splitting models into multiple specification is not only easier to understand, but gives some more clues when we see errors. Add the possibility to create container monitors, whose only purpose is to host other nested monitors. Enabling a container monitor enables all nested ones, but it's still possible to enable nested monitors independently. Add the sched monitor as first container, for now empty. Signed-off-by: Gabriele Monaco <gmonaco@redhat.com> --- include/linux/rv.h | 2 +- kernel/trace/rv/Kconfig | 1 + kernel/trace/rv/Makefile | 1 + kernel/trace/rv/monitors/sched/Kconfig | 12 ++ kernel/trace/rv/monitors/sched/sched.c | 38 +++++++ kernel/trace/rv/monitors/sched/sched.h | 3 + kernel/trace/rv/monitors/wip/wip.c | 2 +- kernel/trace/rv/monitors/wwnr/wwnr.c | 2 +- kernel/trace/rv/rv.c | 151 +++++++++++++++++++++---- kernel/trace/rv/rv.h | 4 + kernel/trace/rv/rv_reactors.c | 28 ++++- 11 files changed, 215 insertions(+), 29 deletions(-) create mode 100644 kernel/trace/rv/monitors/sched/Kconfig create mode 100644 kernel/trace/rv/monitors/sched/sched.c create mode 100644 kernel/trace/rv/monitors/sched/sched.h