[PATCH v3 0/5] rv: Clean up & simplify

[PATCH v3 0/5] rv: Clean up & simplify

[Nam Cao]

Hi,

This series removes some redundant code and simply RV.

v3:
  - fix up a unused variable build error

v2:
  - drop the "nop" reactor removal patch
  - clarify commit description of reference counter removal patch

Nam Cao (5):
  rv: Remove unused field in struct rv_monitor_def
  rv: Merge struct rv_monitor_def into struct rv_monitor
  rv: Merge struct rv_reactor_def into struct rv_reactor
  rv: Remove rv_reactor's reference counter
  rv: Remove struct rv_monitor::reacting

 include/linux/rv.h            |   8 ++
 kernel/trace/rv/rv.c          | 210 +++++++++++++++-------------------
 kernel/trace/rv/rv.h          |  39 +------
 kernel/trace/rv/rv_reactors.c | 136 +++++++---------------
 4 files changed, 148 insertions(+), 245 deletions(-)

-- 
2.39.5

[PATCH v3 1/5] rv: Remove unused field in struct rv_monitor_def

[Nam Cao]

rv_monitor_def::task_monitor is not used. Delete it.

Reviewed-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Nam Cao <namcao@linutronix.de>
---
 kernel/trace/rv/rv.h | 1 -
 1 file changed, 1 deletion(-)

diff --git a/kernel/trace/rv/rv.h b/kernel/trace/rv/rv.h
index 98fca0a1adbc..873364094402 100644
--- a/kernel/trace/rv/rv.h
+++ b/kernel/trace/rv/rv.h
@@ -41,7 +41,6 @@ struct rv_monitor_def {
 	struct rv_reactor_def	*rdef;
 	bool			reacting;
 #endif
-	bool			task_monitor;
 };
 
 struct dentry *get_monitors_root(void);
-- 
2.39.5

[PATCH v3 2/5] rv: Merge struct rv_monitor_def into struct rv_monitor

[Nam Cao]

Each struct rv_monitor has a unique struct rv_monitor_def associated with
it. struct rv_monitor is statically allocated, while struct rv_monitor_def
is dynamically allocated.

This makes the code more complicated than it should be:

  - Lookup is required to get the associated rv_monitor_def from rv_monitor

  - Dynamic memory allocation is required for rv_monitor_def. This is
    harder to get right compared to static memory. For instance, there is
    an existing mistake: rv_unregister_monitor() does not free the memory
    allocated by rv_register_monitor(). This is fortunately not a real
    memory leak problem, as rv_unregister_monitor() is never called.

Simplify and merge rv_monitor_def into rv_monitor.

Reviewed-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Nam Cao <namcao@linutronix.de>
---
 include/linux/rv.h            |   8 ++
 kernel/trace/rv/rv.c          | 211 +++++++++++++++-------------------
 kernel/trace/rv/rv.h          |  27 ++---
 kernel/trace/rv/rv_reactors.c |  62 +++++-----
 4 files changed, 140 insertions(+), 168 deletions(-)

diff --git a/include/linux/rv.h b/include/linux/rv.h
index 97baf58d88b2..dba53aecdfab 100644
--- a/include/linux/rv.h
+++ b/include/linux/rv.h
@@ -7,6 +7,9 @@
 #ifndef _LINUX_RV_H
 #define _LINUX_RV_H
 
+#include <linux/types.h>
+#include <linux/list.h>
+
 #define MAX_DA_NAME_LEN	32
 
 #ifdef CONFIG_RV
@@ -98,8 +101,13 @@ struct rv_monitor {
 	void			(*disable)(void);
 	void			(*reset)(void);
 #ifdef CONFIG_RV_REACTORS
+	struct rv_reactor_def	*rdef;
 	__printf(1, 2) void	(*react)(const char *msg, ...);
+	bool			reacting;
 #endif
+	struct list_head	list;
+	struct rv_monitor	*parent;
+	struct dentry		*root_d;
 };
 
 bool rv_monitoring_on(void);
diff --git a/kernel/trace/rv/rv.c b/kernel/trace/rv/rv.c
index 3127dbfc722a..08d0bcc715bf 100644
--- a/kernel/trace/rv/rv.c
+++ b/kernel/trace/rv/rv.c
@@ -210,9 +210,9 @@ void rv_put_task_monitor_slot(int slot)
  * 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)
+bool rv_is_nested_monitor(struct rv_monitor *mon)
 {
-	return mdef->parent != NULL;
+	return mon->parent != NULL;
 }
 
 /*
@@ -223,16 +223,16 @@ bool rv_is_nested_monitor(struct rv_monitor_def *mdef)
  * for enable()/disable(). Use this condition to find empty containers.
  * Keep both conditions in case we have some non-compliant containers.
  */
-bool rv_is_container_monitor(struct rv_monitor_def *mdef)
+bool rv_is_container_monitor(struct rv_monitor *mon)
 {
-	struct rv_monitor_def *next;
+	struct rv_monitor *next;
 
-	if (list_is_last(&mdef->list, &rv_monitors_list))
+	if (list_is_last(&mon->list, &rv_monitors_list))
 		return false;
 
-	next = list_next_entry(mdef, list);
+	next = list_next_entry(mon, list);
 
-	return next->parent == mdef->monitor || !mdef->monitor->enable;
+	return next->parent == mon || !mon->enable;
 }
 
 /*
@@ -241,10 +241,10 @@ bool rv_is_container_monitor(struct rv_monitor_def *mdef)
 static ssize_t monitor_enable_read_data(struct file *filp, char __user *user_buf, size_t count,
 					loff_t *ppos)
 {
-	struct rv_monitor_def *mdef = filp->private_data;
+	struct rv_monitor *mon = filp->private_data;
 	const char *buff;
 
-	buff = mdef->monitor->enabled ? "1\n" : "0\n";
+	buff = mon->enabled ? "1\n" : "0\n";
 
 	return simple_read_from_buffer(user_buf, count, ppos, buff, strlen(buff)+1);
 }
@@ -252,14 +252,14 @@ static ssize_t monitor_enable_read_data(struct file *filp, char __user *user_buf
 /*
  * __rv_disable_monitor - disabled an enabled monitor
  */
-static int __rv_disable_monitor(struct rv_monitor_def *mdef, bool sync)
+static int __rv_disable_monitor(struct rv_monitor *mon, bool sync)
 {
 	lockdep_assert_held(&rv_interface_lock);
 
-	if (mdef->monitor->enabled) {
-		mdef->monitor->enabled = 0;
-		if (mdef->monitor->disable)
-			mdef->monitor->disable();
+	if (mon->enabled) {
+		mon->enabled = 0;
+		if (mon->disable)
+			mon->disable();
 
 		/*
 		 * Wait for the execution of all events to finish.
@@ -273,90 +273,90 @@ static int __rv_disable_monitor(struct rv_monitor_def *mdef, bool sync)
 	return 0;
 }
 
-static void rv_disable_single(struct rv_monitor_def *mdef)
+static void rv_disable_single(struct rv_monitor *mon)
 {
-	__rv_disable_monitor(mdef, true);
+	__rv_disable_monitor(mon, true);
 }
 
-static int rv_enable_single(struct rv_monitor_def *mdef)
+static int rv_enable_single(struct rv_monitor *mon)
 {
 	int retval;
 
 	lockdep_assert_held(&rv_interface_lock);
 
-	if (mdef->monitor->enabled)
+	if (mon->enabled)
 		return 0;
 
-	retval = mdef->monitor->enable();
+	retval = mon->enable();
 
 	if (!retval)
-		mdef->monitor->enabled = 1;
+		mon->enabled = 1;
 
 	return retval;
 }
 
-static void rv_disable_container(struct rv_monitor_def *mdef)
+static void rv_disable_container(struct rv_monitor *mon)
 {
-	struct rv_monitor_def *p = mdef;
+	struct rv_monitor *p = mon;
 	int enabled = 0;
 
 	list_for_each_entry_continue(p, &rv_monitors_list, list) {
-		if (p->parent != mdef->monitor)
+		if (p->parent != mon)
 			break;
 		enabled += __rv_disable_monitor(p, false);
 	}
 	if (enabled)
 		tracepoint_synchronize_unregister();
-	mdef->monitor->enabled = 0;
+	mon->enabled = 0;
 }
 
-static int rv_enable_container(struct rv_monitor_def *mdef)
+static int rv_enable_container(struct rv_monitor *mon)
 {
-	struct rv_monitor_def *p = mdef;
+	struct rv_monitor *p = mon;
 	int retval = 0;
 
 	list_for_each_entry_continue(p, &rv_monitors_list, list) {
-		if (retval || p->parent != mdef->monitor)
+		if (retval || p->parent != mon)
 			break;
 		retval = rv_enable_single(p);
 	}
 	if (retval)
-		rv_disable_container(mdef);
+		rv_disable_container(mon);
 	else
-		mdef->monitor->enabled = 1;
+		mon->enabled = 1;
 	return retval;
 }
 
 /**
  * rv_disable_monitor - disable a given runtime monitor
- * @mdef: Pointer to the monitor definition structure.
+ * @mon: Pointer to the monitor definition structure.
  *
  * Returns 0 on success.
  */
-int rv_disable_monitor(struct rv_monitor_def *mdef)
+int rv_disable_monitor(struct rv_monitor *mon)
 {
-	if (rv_is_container_monitor(mdef))
-		rv_disable_container(mdef);
+	if (rv_is_container_monitor(mon))
+		rv_disable_container(mon);
 	else
-		rv_disable_single(mdef);
+		rv_disable_single(mon);
 
 	return 0;
 }
 
 /**
  * rv_enable_monitor - enable a given runtime monitor
- * @mdef: Pointer to the monitor definition structure.
+ * @mon: Pointer to the monitor definition structure.
  *
  * Returns 0 on success, error otherwise.
  */
-int rv_enable_monitor(struct rv_monitor_def *mdef)
+int rv_enable_monitor(struct rv_monitor *mon)
 {
 	int retval;
 
-	if (rv_is_container_monitor(mdef))
-		retval = rv_enable_container(mdef);
+	if (rv_is_container_monitor(mon))
+		retval = rv_enable_container(mon);
 	else
-		retval = rv_enable_single(mdef);
+		retval = rv_enable_single(mon);
 
 	return retval;
 }
@@ -367,7 +367,7 @@ int rv_enable_monitor(struct rv_monitor_def *mdef)
 static ssize_t monitor_enable_write_data(struct file *filp, const char __user *user_buf,
 					 size_t count, loff_t *ppos)
 {
-	struct rv_monitor_def *mdef = filp->private_data;
+	struct rv_monitor *mon = filp->private_data;
 	int retval;
 	bool val;
 
@@ -378,9 +378,9 @@ static ssize_t monitor_enable_write_data(struct file *filp, const char __user *u
 	mutex_lock(&rv_interface_lock);
 
 	if (val)
-		retval = rv_enable_monitor(mdef);
+		retval = rv_enable_monitor(mon);
 	else
-		retval = rv_disable_monitor(mdef);
+		retval = rv_disable_monitor(mon);
 
 	mutex_unlock(&rv_interface_lock);
 
@@ -399,12 +399,12 @@ static const struct file_operations interface_enable_fops = {
 static ssize_t monitor_desc_read_data(struct file *filp, char __user *user_buf, size_t count,
 				      loff_t *ppos)
 {
-	struct rv_monitor_def *mdef = filp->private_data;
+	struct rv_monitor *mon = filp->private_data;
 	char buff[256];
 
 	memset(buff, 0, sizeof(buff));
 
-	snprintf(buff, sizeof(buff), "%s\n", mdef->monitor->description);
+	snprintf(buff, sizeof(buff), "%s\n", mon->description);
 
 	return simple_read_from_buffer(user_buf, count, ppos, buff, strlen(buff) + 1);
 }
@@ -419,37 +419,37 @@ 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, struct rv_monitor_def *parent)
+static int create_monitor_dir(struct rv_monitor *mon, struct rv_monitor *parent)
 {
 	struct dentry *root = parent ? parent->root_d : get_monitors_root();
-	const char *name = mdef->monitor->name;
+	const char *name = mon->name;
 	struct dentry *tmp;
 	int retval;
 
-	mdef->root_d = rv_create_dir(name, root);
-	if (!mdef->root_d)
+	mon->root_d = rv_create_dir(name, root);
+	if (!mon->root_d)
 		return -ENOMEM;
 
-	tmp = rv_create_file("enable", RV_MODE_WRITE, mdef->root_d, mdef, &interface_enable_fops);
+	tmp = rv_create_file("enable", RV_MODE_WRITE, mon->root_d, mon, &interface_enable_fops);
 	if (!tmp) {
 		retval = -ENOMEM;
 		goto out_remove_root;
 	}
 
-	tmp = rv_create_file("desc", RV_MODE_READ, mdef->root_d, mdef, &interface_desc_fops);
+	tmp = rv_create_file("desc", RV_MODE_READ, mon->root_d, mon, &interface_desc_fops);
 	if (!tmp) {
 		retval = -ENOMEM;
 		goto out_remove_root;
 	}
 
-	retval = reactor_populate_monitor(mdef);
+	retval = reactor_populate_monitor(mon);
 	if (retval)
 		goto out_remove_root;
 
 	return 0;
 
 out_remove_root:
-	rv_remove(mdef->root_d);
+	rv_remove(mon->root_d);
 	return retval;
 }
 
@@ -458,13 +458,12 @@ static int create_monitor_dir(struct rv_monitor_def *mdef, struct rv_monitor_def
  */
 static int monitors_show(struct seq_file *m, void *p)
 {
-	struct rv_monitor_def *mon_def = p;
+	struct rv_monitor *mon = p;
 
-	if (mon_def->parent)
-		seq_printf(m, "%s:%s\n", mon_def->parent->name,
-			   mon_def->monitor->name);
+	if (mon->parent)
+		seq_printf(m, "%s:%s\n", mon->parent->name, mon->name);
 	else
-		seq_printf(m, "%s\n", mon_def->monitor->name);
+		seq_printf(m, "%s\n", mon->name);
 	return 0;
 }
 
@@ -496,13 +495,13 @@ static void *available_monitors_next(struct seq_file *m, void *p, loff_t *pos)
  */
 static void *enabled_monitors_next(struct seq_file *m, void *p, loff_t *pos)
 {
-	struct rv_monitor_def *m_def = p;
+	struct rv_monitor *mon = p;
 
 	(*pos)++;
 
-	list_for_each_entry_continue(m_def, &rv_monitors_list, list) {
-		if (m_def->monitor->enabled)
-			return m_def;
+	list_for_each_entry_continue(mon, &rv_monitors_list, list) {
+		if (mon->enabled)
+			return mon;
 	}
 
 	return NULL;
@@ -510,7 +509,7 @@ static void *enabled_monitors_next(struct seq_file *m, void *p, loff_t *pos)
 
 static void *enabled_monitors_start(struct seq_file *m, loff_t *pos)
 {
-	struct rv_monitor_def *m_def;
+	struct rv_monitor *mon;
 	loff_t l;
 
 	mutex_lock(&rv_interface_lock);
@@ -518,15 +517,15 @@ static void *enabled_monitors_start(struct seq_file *m, loff_t *pos)
 	if (list_empty(&rv_monitors_list))
 		return NULL;
 
-	m_def = list_entry(&rv_monitors_list, struct rv_monitor_def, list);
+	mon = list_entry(&rv_monitors_list, struct rv_monitor, list);
 
 	for (l = 0; l <= *pos; ) {
-		m_def = enabled_monitors_next(m, m_def, &l);
-		if (!m_def)
+		mon = enabled_monitors_next(m, mon, &l);
+		if (!mon)
 			break;
 	}
 
-	return m_def;
+	return mon;
 }
 
 /*
@@ -566,13 +565,13 @@ static const struct file_operations available_monitors_ops = {
  */
 static void disable_all_monitors(void)
 {
-	struct rv_monitor_def *mdef;
+	struct rv_monitor *mon;
 	int enabled = 0;
 
 	mutex_lock(&rv_interface_lock);
 
-	list_for_each_entry(mdef, &rv_monitors_list, list)
-		enabled += __rv_disable_monitor(mdef, false);
+	list_for_each_entry(mon, &rv_monitors_list, list)
+		enabled += __rv_disable_monitor(mon, false);
 
 	if (enabled) {
 		/*
@@ -598,7 +597,7 @@ static ssize_t enabled_monitors_write(struct file *filp, const char __user *user
 				      size_t count, loff_t *ppos)
 {
 	char buff[MAX_RV_MONITOR_NAME_SIZE + 2];
-	struct rv_monitor_def *mdef;
+	struct rv_monitor *mon;
 	int retval = -EINVAL;
 	bool enable = true;
 	char *ptr, *tmp;
@@ -633,17 +632,17 @@ static ssize_t enabled_monitors_write(struct file *filp, const char __user *user
 	if (tmp)
 		ptr = tmp+1;
 
-	list_for_each_entry(mdef, &rv_monitors_list, list) {
-		if (strcmp(ptr, mdef->monitor->name) != 0)
+	list_for_each_entry(mon, &rv_monitors_list, list) {
+		if (strcmp(ptr, mon->name) != 0)
 			continue;
 
 		/*
 		 * Monitor found!
 		 */
 		if (enable)
-			retval = rv_enable_monitor(mdef);
+			retval = rv_enable_monitor(mon);
 		else
-			retval = rv_disable_monitor(mdef);
+			retval = rv_disable_monitor(mon);
 
 		if (!retval)
 			retval = count;
@@ -698,11 +697,11 @@ static void turn_monitoring_off(void)
 
 static void reset_all_monitors(void)
 {
-	struct rv_monitor_def *mdef;
+	struct rv_monitor *mon;
 
-	list_for_each_entry(mdef, &rv_monitors_list, list) {
-		if (mdef->monitor->enabled && mdef->monitor->reset)
-			mdef->monitor->reset();
+	list_for_each_entry(mon, &rv_monitors_list, list) {
+		if (mon->enabled && mon->reset)
+			mon->reset();
 	}
 }
 
@@ -762,10 +761,10 @@ static const struct file_operations monitoring_on_fops = {
 	.read   = monitoring_on_read_data,
 };
 
-static void destroy_monitor_dir(struct rv_monitor_def *mdef)
+static void destroy_monitor_dir(struct rv_monitor *mon)
 {
-	reactor_cleanup_monitor(mdef);
-	rv_remove(mdef->root_d);
+	reactor_cleanup_monitor(mon);
+	rv_remove(mon->root_d);
 }
 
 /**
@@ -777,7 +776,7 @@ static void destroy_monitor_dir(struct rv_monitor_def *mdef)
  */
 int rv_register_monitor(struct rv_monitor *monitor, struct rv_monitor *parent)
 {
-	struct rv_monitor_def *r, *p = NULL;
+	struct rv_monitor *r;
 	int retval = 0;
 
 	if (strlen(monitor->name) >= MAX_RV_MONITOR_NAME_SIZE) {
@@ -789,49 +788,31 @@ int rv_register_monitor(struct rv_monitor *monitor, struct rv_monitor *parent)
 	mutex_lock(&rv_interface_lock);
 
 	list_for_each_entry(r, &rv_monitors_list, list) {
-		if (strcmp(monitor->name, r->monitor->name) == 0) {
+		if (strcmp(monitor->name, r->name) == 0) {
 			pr_info("Monitor %s is already registered\n", monitor->name);
 			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)) {
+	if (parent && rv_is_nested_monitor(parent)) {
 		pr_info("Parent monitor %s is already nested, cannot nest further\n",
 			parent->name);
 		retval = -EINVAL;
 		goto out_unlock;
 	}
 
-	r = kzalloc(sizeof(struct rv_monitor_def), GFP_KERNEL);
-	if (!r) {
-		retval = -ENOMEM;
-		goto out_unlock;
-	}
-
-	r->monitor = monitor;
-	r->parent = parent;
+	monitor->parent = parent;
 
-	retval = create_monitor_dir(r, p);
-	if (retval) {
-		kfree(r);
-		goto out_unlock;
-	}
+	retval = create_monitor_dir(monitor, parent);
+	if (retval)
+		return retval;
 
 	/* keep children close to the parent for easier visualisation */
-	if (p)
-		list_add(&r->list, &p->list);
+	if (parent)
+		list_add(&monitor->list, &parent->list);
 	else
-		list_add_tail(&r->list, &rv_monitors_list);
+		list_add_tail(&monitor->list, &rv_monitors_list);
 
 out_unlock:
 	mutex_unlock(&rv_interface_lock);
@@ -846,17 +827,11 @@ int rv_register_monitor(struct rv_monitor *monitor, struct rv_monitor *parent)
  */
 int rv_unregister_monitor(struct rv_monitor *monitor)
 {
-	struct rv_monitor_def *ptr, *next;
-
 	mutex_lock(&rv_interface_lock);
 
-	list_for_each_entry_safe(ptr, next, &rv_monitors_list, list) {
-		if (strcmp(monitor->name, ptr->monitor->name) == 0) {
-			rv_disable_monitor(ptr);
-			list_del(&ptr->list);
-			destroy_monitor_dir(ptr);
-		}
-	}
+	rv_disable_monitor(monitor);
+	list_del(&monitor->list);
+	destroy_monitor_dir(monitor);
 
 	mutex_unlock(&rv_interface_lock);
 	return 0;
diff --git a/kernel/trace/rv/rv.h b/kernel/trace/rv/rv.h
index 873364094402..f039ec1c9156 100644
--- a/kernel/trace/rv/rv.h
+++ b/kernel/trace/rv/rv.h
@@ -32,34 +32,23 @@ struct rv_reactor_def {
 };
 #endif
 
-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;
-	bool			reacting;
-#endif
-};
-
 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);
+int rv_disable_monitor(struct rv_monitor *mon);
+int rv_enable_monitor(struct rv_monitor *mon);
+bool rv_is_container_monitor(struct rv_monitor *mon);
+bool rv_is_nested_monitor(struct rv_monitor *mon);
 
 #ifdef CONFIG_RV_REACTORS
-int reactor_populate_monitor(struct rv_monitor_def *mdef);
-void reactor_cleanup_monitor(struct rv_monitor_def *mdef);
+int reactor_populate_monitor(struct rv_monitor *mon);
+void reactor_cleanup_monitor(struct rv_monitor *mon);
 int init_rv_reactors(struct dentry *root_dir);
 #else
-static inline int reactor_populate_monitor(struct rv_monitor_def *mdef)
+static inline int reactor_populate_monitor(struct rv_monitor *mon)
 {
 	return 0;
 }
 
-static inline void reactor_cleanup_monitor(struct rv_monitor_def *mdef)
+static inline void reactor_cleanup_monitor(struct rv_monitor *mon)
 {
 	return;
 }
diff --git a/kernel/trace/rv/rv_reactors.c b/kernel/trace/rv/rv_reactors.c
index 740603670dd1..7cc620a1be1a 100644
--- a/kernel/trace/rv/rv_reactors.c
+++ b/kernel/trace/rv/rv_reactors.c
@@ -138,10 +138,10 @@ static const struct file_operations available_reactors_ops = {
  */
 static int monitor_reactor_show(struct seq_file *m, void *p)
 {
-	struct rv_monitor_def *mdef = m->private;
+	struct rv_monitor *mon = m->private;
 	struct rv_reactor_def *rdef = p;
 
-	if (mdef->rdef == rdef)
+	if (mon->rdef == rdef)
 		seq_printf(m, "[%s]\n", rdef->reactor->name);
 	else
 		seq_printf(m, "%s\n", rdef->reactor->name);
@@ -158,41 +158,41 @@ static const struct seq_operations monitor_reactors_seq_ops = {
 	.show	= monitor_reactor_show
 };
 
-static void monitor_swap_reactors_single(struct rv_monitor_def *mdef,
+static void monitor_swap_reactors_single(struct rv_monitor *mon,
 					 struct rv_reactor_def *rdef,
 					 bool reacting, bool nested)
 {
 	bool monitor_enabled;
 
 	/* nothing to do */
-	if (mdef->rdef == rdef)
+	if (mon->rdef == rdef)
 		return;
 
-	monitor_enabled = mdef->monitor->enabled;
+	monitor_enabled = mon->enabled;
 	if (monitor_enabled)
-		rv_disable_monitor(mdef);
+		rv_disable_monitor(mon);
 
 	/* swap reactor's usage */
-	mdef->rdef->counter--;
+	mon->rdef->counter--;
 	rdef->counter++;
 
-	mdef->rdef = rdef;
-	mdef->reacting = reacting;
-	mdef->monitor->react = rdef->reactor->react;
+	mon->rdef = rdef;
+	mon->reacting = reacting;
+	mon->react = rdef->reactor->react;
 
 	/* enable only once if iterating through a container */
 	if (monitor_enabled && !nested)
-		rv_enable_monitor(mdef);
+		rv_enable_monitor(mon);
 }
 
-static void monitor_swap_reactors(struct rv_monitor_def *mdef,
+static void monitor_swap_reactors(struct rv_monitor *mon,
 				  struct rv_reactor_def *rdef, bool reacting)
 {
-	struct rv_monitor_def *p = mdef;
+	struct rv_monitor *p = mon;
 
-	if (rv_is_container_monitor(mdef))
+	if (rv_is_container_monitor(mon))
 		list_for_each_entry_continue(p, &rv_monitors_list, list) {
-			if (p->parent != mdef->monitor)
+			if (p->parent != mon)
 				break;
 			monitor_swap_reactors_single(p, rdef, reacting, true);
 		}
@@ -202,7 +202,7 @@ static void monitor_swap_reactors(struct rv_monitor_def *mdef,
 	 * 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);
+	monitor_swap_reactors_single(mon, rdef, reacting, false);
 }
 
 static ssize_t
@@ -210,7 +210,7 @@ monitor_reactors_write(struct file *file, const char __user *user_buf,
 		      size_t count, loff_t *ppos)
 {
 	char buff[MAX_RV_REACTOR_NAME_SIZE + 2];
-	struct rv_monitor_def *mdef;
+	struct rv_monitor *mon;
 	struct rv_reactor_def *rdef;
 	struct seq_file *seq_f;
 	int retval = -EINVAL;
@@ -237,7 +237,7 @@ monitor_reactors_write(struct file *file, const char __user *user_buf,
 	 * See monitor_reactors_open()
 	 */
 	seq_f = file->private_data;
-	mdef = seq_f->private;
+	mon = seq_f->private;
 
 	mutex_lock(&rv_interface_lock);
 
@@ -252,7 +252,7 @@ monitor_reactors_write(struct file *file, const char __user *user_buf,
 		else
 			enable = true;
 
-		monitor_swap_reactors(mdef, rdef, enable);
+		monitor_swap_reactors(mon, rdef, enable);
 
 		retval = count;
 		break;
@@ -268,7 +268,7 @@ monitor_reactors_write(struct file *file, const char __user *user_buf,
  */
 static int monitor_reactors_open(struct inode *inode, struct file *file)
 {
-	struct rv_monitor_def *mdef = inode->i_private;
+	struct rv_monitor *mon = inode->i_private;
 	struct seq_file *seq_f;
 	int ret;
 
@@ -284,7 +284,7 @@ static int monitor_reactors_open(struct inode *inode, struct file *file)
 	/*
 	 * Copy the create file "private" data to the seq_file private data.
 	 */
-	seq_f->private = mdef;
+	seq_f->private = mon;
 
 	return 0;
 };
@@ -454,37 +454,37 @@ static const struct file_operations reacting_on_fops = {
 
 /**
  * reactor_populate_monitor - creates per monitor reactors file
- * @mdef:	monitor's definition.
+ * @mon:	The monitor.
  *
  * Returns 0 if successful, error otherwise.
  */
-int reactor_populate_monitor(struct rv_monitor_def *mdef)
+int reactor_populate_monitor(struct rv_monitor *mon)
 {
 	struct dentry *tmp;
 
-	tmp = rv_create_file("reactors", RV_MODE_WRITE, mdef->root_d, mdef, &monitor_reactors_ops);
+	tmp = rv_create_file("reactors", RV_MODE_WRITE, mon->root_d, mon, &monitor_reactors_ops);
 	if (!tmp)
 		return -ENOMEM;
 
 	/*
 	 * Configure as the rv_nop reactor.
 	 */
-	mdef->rdef = get_reactor_rdef_by_name("nop");
-	mdef->rdef->counter++;
-	mdef->reacting = false;
+	mon->rdef = get_reactor_rdef_by_name("nop");
+	mon->rdef->counter++;
+	mon->reacting = false;
 
 	return 0;
 }
 
 /**
  * reactor_cleanup_monitor - cleanup a monitor reference
- * @mdef:       monitor's definition.
+ * @mon:       the monitor.
  */
-void reactor_cleanup_monitor(struct rv_monitor_def *mdef)
+void reactor_cleanup_monitor(struct rv_monitor *mon)
 {
 	lockdep_assert_held(&rv_interface_lock);
-	mdef->rdef->counter--;
-	WARN_ON_ONCE(mdef->rdef->counter < 0);
+	mon->rdef->counter--;
+	WARN_ON_ONCE(mon->rdef->counter < 0);
 }
 
 /*
-- 
2.39.5

[PATCH v3 3/5] rv: Merge struct rv_reactor_def into struct rv_reactor

[Nam Cao]

Each struct rv_reactor has a unique struct rv_reactor_def associated with
it. struct rv_reactor is statically allocated, while struct rv_reactor_def
is dynamically allocated.

This makes the code more complicated than it should be:

  - Lookup is required to get the associated rv_reactor_def from rv_reactor

  - Dynamic memory allocation is required for rv_reactor_def. This is
    harder to get right compared to static memory. For instance, there is
    an existing mistake: rv_unregister_reactor() does not free the memory
    allocated by rv_register_reactor(). This is fortunately not a real
    memory leak problem as rv_unregister_reactor() is never called.

Simplify and merge rv_reactor_def into rv_reactor.

Reviewed-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Nam Cao <namcao@linutronix.de>
---
 include/linux/rv.h            |  5 +-
 kernel/trace/rv/rv.h          |  9 ----
 kernel/trace/rv/rv_reactors.c | 92 +++++++++++++++--------------------
 3 files changed, 43 insertions(+), 63 deletions(-)

diff --git a/include/linux/rv.h b/include/linux/rv.h
index dba53aecdfab..c22c9b8c1567 100644
--- a/include/linux/rv.h
+++ b/include/linux/rv.h
@@ -90,6 +90,9 @@ struct rv_reactor {
 	const char		*name;
 	const char		*description;
 	__printf(1, 2) void	(*react)(const char *msg, ...);
+	struct list_head	list;
+	/* protected by the monitor interface lock */
+	int			counter;
 };
 #endif
 
@@ -101,7 +104,7 @@ struct rv_monitor {
 	void			(*disable)(void);
 	void			(*reset)(void);
 #ifdef CONFIG_RV_REACTORS
-	struct rv_reactor_def	*rdef;
+	struct rv_reactor	*reactor;
 	__printf(1, 2) void	(*react)(const char *msg, ...);
 	bool			reacting;
 #endif
diff --git a/kernel/trace/rv/rv.h b/kernel/trace/rv/rv.h
index f039ec1c9156..8c38f9dd41bc 100644
--- a/kernel/trace/rv/rv.h
+++ b/kernel/trace/rv/rv.h
@@ -23,15 +23,6 @@ struct rv_interface {
 extern struct mutex rv_interface_lock;
 extern struct list_head rv_monitors_list;
 
-#ifdef CONFIG_RV_REACTORS
-struct rv_reactor_def {
-	struct list_head	list;
-	struct rv_reactor	*reactor;
-	/* protected by the monitor interface lock */
-	int			counter;
-};
-#endif
-
 struct dentry *get_monitors_root(void);
 int rv_disable_monitor(struct rv_monitor *mon);
 int rv_enable_monitor(struct rv_monitor *mon);
diff --git a/kernel/trace/rv/rv_reactors.c b/kernel/trace/rv/rv_reactors.c
index 7cc620a1be1a..2c7909e6d0e7 100644
--- a/kernel/trace/rv/rv_reactors.c
+++ b/kernel/trace/rv/rv_reactors.c
@@ -70,12 +70,12 @@
  */
 static LIST_HEAD(rv_reactors_list);
 
-static struct rv_reactor_def *get_reactor_rdef_by_name(char *name)
+static struct rv_reactor *get_reactor_rdef_by_name(char *name)
 {
-	struct rv_reactor_def *r;
+	struct rv_reactor *r;
 
 	list_for_each_entry(r, &rv_reactors_list, list) {
-		if (strcmp(name, r->reactor->name) == 0)
+		if (strcmp(name, r->name) == 0)
 			return r;
 	}
 	return NULL;
@@ -86,9 +86,9 @@ static struct rv_reactor_def *get_reactor_rdef_by_name(char *name)
  */
 static int reactors_show(struct seq_file *m, void *p)
 {
-	struct rv_reactor_def *rea_def = p;
+	struct rv_reactor *reactor = p;
 
-	seq_printf(m, "%s\n", rea_def->reactor->name);
+	seq_printf(m, "%s\n", reactor->name);
 	return 0;
 }
 
@@ -139,12 +139,12 @@ static const struct file_operations available_reactors_ops = {
 static int monitor_reactor_show(struct seq_file *m, void *p)
 {
 	struct rv_monitor *mon = m->private;
-	struct rv_reactor_def *rdef = p;
+	struct rv_reactor *reactor = p;
 
-	if (mon->rdef == rdef)
-		seq_printf(m, "[%s]\n", rdef->reactor->name);
+	if (mon->reactor == reactor)
+		seq_printf(m, "[%s]\n", reactor->name);
 	else
-		seq_printf(m, "%s\n", rdef->reactor->name);
+		seq_printf(m, "%s\n", reactor->name);
 	return 0;
 }
 
@@ -159,13 +159,13 @@ static const struct seq_operations monitor_reactors_seq_ops = {
 };
 
 static void monitor_swap_reactors_single(struct rv_monitor *mon,
-					 struct rv_reactor_def *rdef,
+					 struct rv_reactor *reactor,
 					 bool reacting, bool nested)
 {
 	bool monitor_enabled;
 
 	/* nothing to do */
-	if (mon->rdef == rdef)
+	if (mon->reactor == reactor)
 		return;
 
 	monitor_enabled = mon->enabled;
@@ -173,12 +173,12 @@ static void monitor_swap_reactors_single(struct rv_monitor *mon,
 		rv_disable_monitor(mon);
 
 	/* swap reactor's usage */
-	mon->rdef->counter--;
-	rdef->counter++;
+	mon->reactor->counter--;
+	reactor->counter++;
 
-	mon->rdef = rdef;
+	mon->reactor = reactor;
 	mon->reacting = reacting;
-	mon->react = rdef->reactor->react;
+	mon->react = reactor->react;
 
 	/* enable only once if iterating through a container */
 	if (monitor_enabled && !nested)
@@ -186,7 +186,7 @@ static void monitor_swap_reactors_single(struct rv_monitor *mon,
 }
 
 static void monitor_swap_reactors(struct rv_monitor *mon,
-				  struct rv_reactor_def *rdef, bool reacting)
+				  struct rv_reactor *reactor, bool reacting)
 {
 	struct rv_monitor *p = mon;
 
@@ -194,7 +194,7 @@ static void monitor_swap_reactors(struct rv_monitor *mon,
 		list_for_each_entry_continue(p, &rv_monitors_list, list) {
 			if (p->parent != mon)
 				break;
-			monitor_swap_reactors_single(p, rdef, reacting, true);
+			monitor_swap_reactors_single(p, reactor, reacting, true);
 		}
 	/*
 	 * This call enables and disables the monitor if they were active.
@@ -202,7 +202,7 @@ static void monitor_swap_reactors(struct rv_monitor *mon,
 	 * All nested monitors are enabled also if they were off, we may refine
 	 * this logic in the future.
 	 */
-	monitor_swap_reactors_single(mon, rdef, reacting, false);
+	monitor_swap_reactors_single(mon, reactor, reacting, false);
 }
 
 static ssize_t
@@ -211,7 +211,7 @@ monitor_reactors_write(struct file *file, const char __user *user_buf,
 {
 	char buff[MAX_RV_REACTOR_NAME_SIZE + 2];
 	struct rv_monitor *mon;
-	struct rv_reactor_def *rdef;
+	struct rv_reactor *reactor;
 	struct seq_file *seq_f;
 	int retval = -EINVAL;
 	bool enable;
@@ -243,16 +243,16 @@ monitor_reactors_write(struct file *file, const char __user *user_buf,
 
 	retval = -EINVAL;
 
-	list_for_each_entry(rdef, &rv_reactors_list, list) {
-		if (strcmp(ptr, rdef->reactor->name) != 0)
+	list_for_each_entry(reactor, &rv_reactors_list, list) {
+		if (strcmp(ptr, reactor->name) != 0)
 			continue;
 
-		if (rdef == get_reactor_rdef_by_name("nop"))
+		if (strcmp(reactor->name, "nop"))
 			enable = false;
 		else
 			enable = true;
 
-		monitor_swap_reactors(mon, rdef, enable);
+		monitor_swap_reactors(mon, reactor, enable);
 
 		retval = count;
 		break;
@@ -299,23 +299,16 @@ static const struct file_operations monitor_reactors_ops = {
 
 static int __rv_register_reactor(struct rv_reactor *reactor)
 {
-	struct rv_reactor_def *r;
+	struct rv_reactor *r;
 
 	list_for_each_entry(r, &rv_reactors_list, list) {
-		if (strcmp(reactor->name, r->reactor->name) == 0) {
+		if (strcmp(reactor->name, r->name) == 0) {
 			pr_info("Reactor %s is already registered\n", reactor->name);
 			return -EINVAL;
 		}
 	}
 
-	r = kzalloc(sizeof(struct rv_reactor_def), GFP_KERNEL);
-	if (!r)
-		return -ENOMEM;
-
-	r->reactor = reactor;
-	r->counter = 0;
-
-	list_add_tail(&r->list, &rv_reactors_list);
+	list_add_tail(&reactor->list, &rv_reactors_list);
 
 	return 0;
 }
@@ -350,26 +343,19 @@ int rv_register_reactor(struct rv_reactor *reactor)
  */
 int rv_unregister_reactor(struct rv_reactor *reactor)
 {
-	struct rv_reactor_def *ptr, *next;
 	int ret = 0;
 
 	mutex_lock(&rv_interface_lock);
 
-	list_for_each_entry_safe(ptr, next, &rv_reactors_list, list) {
-		if (strcmp(reactor->name, ptr->reactor->name) == 0) {
-
-			if (!ptr->counter) {
-				list_del(&ptr->list);
-			} else {
-				printk(KERN_WARNING
-				       "rv: the rv_reactor %s is in use by %d monitor(s)\n",
-				       ptr->reactor->name, ptr->counter);
-				printk(KERN_WARNING "rv: the rv_reactor %s cannot be removed\n",
-				       ptr->reactor->name);
-				ret = -EBUSY;
-				break;
-			}
-		}
+	if (!reactor->counter) {
+		list_del(&reactor->list);
+	} else {
+		printk(KERN_WARNING
+		       "rv: the rv_reactor %s is in use by %d monitor(s)\n",
+		       reactor->name, reactor->counter);
+		printk(KERN_WARNING "rv: the rv_reactor %s cannot be removed\n",
+		       reactor->name);
+		ret = -EBUSY;
 	}
 
 	mutex_unlock(&rv_interface_lock);
@@ -469,8 +455,8 @@ int reactor_populate_monitor(struct rv_monitor *mon)
 	/*
 	 * Configure as the rv_nop reactor.
 	 */
-	mon->rdef = get_reactor_rdef_by_name("nop");
-	mon->rdef->counter++;
+	mon->reactor = get_reactor_rdef_by_name("nop");
+	mon->reactor->counter++;
 	mon->reacting = false;
 
 	return 0;
@@ -483,8 +469,8 @@ int reactor_populate_monitor(struct rv_monitor *mon)
 void reactor_cleanup_monitor(struct rv_monitor *mon)
 {
 	lockdep_assert_held(&rv_interface_lock);
-	mon->rdef->counter--;
-	WARN_ON_ONCE(mon->rdef->counter < 0);
+	mon->reactor->counter--;
+	WARN_ON_ONCE(mon->reactor->counter < 0);
 }
 
 /*
-- 
2.39.5

[PATCH v3 4/5] rv: Remove rv_reactor's reference counter

[Nam Cao]

rv_reactor has a reference counter to ensure it is not removed while
monitors are still using it.

However, this is futile, as __exit functions are not expected to fail and
will proceed normally despite rv_unregister_reactor() returning an error.

At the moment, reactors do not support being built as modules, therefore
they are never removed and the reference counters are not necessary.

If we support building RV reactors as modules in the future, kernel
module's centralized facilities such as try_module_get(), module_put() or
MODULE_SOFTDEP should be used instead of this custom implementation.

Remove this reference counter.

Reviewed-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Nam Cao <namcao@linutronix.de>
---
 include/linux/rv.h            |  2 --
 kernel/trace/rv/rv.c          |  1 -
 kernel/trace/rv/rv.h          |  6 ------
 kernel/trace/rv/rv_reactors.c | 33 ++-------------------------------
 4 files changed, 2 insertions(+), 40 deletions(-)

diff --git a/include/linux/rv.h b/include/linux/rv.h
index c22c9b8c1567..2f867d6f72ba 100644
--- a/include/linux/rv.h
+++ b/include/linux/rv.h
@@ -91,8 +91,6 @@ struct rv_reactor {
 	const char		*description;
 	__printf(1, 2) void	(*react)(const char *msg, ...);
 	struct list_head	list;
-	/* protected by the monitor interface lock */
-	int			counter;
 };
 #endif
 
diff --git a/kernel/trace/rv/rv.c b/kernel/trace/rv/rv.c
index 08d0bcc715bf..2ac0e8bf4e60 100644
--- a/kernel/trace/rv/rv.c
+++ b/kernel/trace/rv/rv.c
@@ -763,7 +763,6 @@ static const struct file_operations monitoring_on_fops = {
 
 static void destroy_monitor_dir(struct rv_monitor *mon)
 {
-	reactor_cleanup_monitor(mon);
 	rv_remove(mon->root_d);
 }
 
diff --git a/kernel/trace/rv/rv.h b/kernel/trace/rv/rv.h
index 8c38f9dd41bc..1485a70c1bf4 100644
--- a/kernel/trace/rv/rv.h
+++ b/kernel/trace/rv/rv.h
@@ -31,7 +31,6 @@ bool rv_is_nested_monitor(struct rv_monitor *mon);
 
 #ifdef CONFIG_RV_REACTORS
 int reactor_populate_monitor(struct rv_monitor *mon);
-void reactor_cleanup_monitor(struct rv_monitor *mon);
 int init_rv_reactors(struct dentry *root_dir);
 #else
 static inline int reactor_populate_monitor(struct rv_monitor *mon)
@@ -39,11 +38,6 @@ static inline int reactor_populate_monitor(struct rv_monitor *mon)
 	return 0;
 }
 
-static inline void reactor_cleanup_monitor(struct rv_monitor *mon)
-{
-	return;
-}
-
 static inline int init_rv_reactors(struct dentry *root_dir)
 {
 	return 0;
diff --git a/kernel/trace/rv/rv_reactors.c b/kernel/trace/rv/rv_reactors.c
index 2c7909e6d0e7..a8e849e6cd85 100644
--- a/kernel/trace/rv/rv_reactors.c
+++ b/kernel/trace/rv/rv_reactors.c
@@ -172,10 +172,6 @@ static void monitor_swap_reactors_single(struct rv_monitor *mon,
 	if (monitor_enabled)
 		rv_disable_monitor(mon);
 
-	/* swap reactor's usage */
-	mon->reactor->counter--;
-	reactor->counter++;
-
 	mon->reactor = reactor;
 	mon->reacting = reacting;
 	mon->react = reactor->react;
@@ -343,23 +339,10 @@ int rv_register_reactor(struct rv_reactor *reactor)
  */
 int rv_unregister_reactor(struct rv_reactor *reactor)
 {
-	int ret = 0;
-
 	mutex_lock(&rv_interface_lock);
-
-	if (!reactor->counter) {
-		list_del(&reactor->list);
-	} else {
-		printk(KERN_WARNING
-		       "rv: the rv_reactor %s is in use by %d monitor(s)\n",
-		       reactor->name, reactor->counter);
-		printk(KERN_WARNING "rv: the rv_reactor %s cannot be removed\n",
-		       reactor->name);
-		ret = -EBUSY;
-	}
-
+	list_del(&reactor->list);
 	mutex_unlock(&rv_interface_lock);
-	return ret;
+	return 0;
 }
 
 /*
@@ -456,23 +439,11 @@ int reactor_populate_monitor(struct rv_monitor *mon)
 	 * Configure as the rv_nop reactor.
 	 */
 	mon->reactor = get_reactor_rdef_by_name("nop");
-	mon->reactor->counter++;
 	mon->reacting = false;
 
 	return 0;
 }
 
-/**
- * reactor_cleanup_monitor - cleanup a monitor reference
- * @mon:       the monitor.
- */
-void reactor_cleanup_monitor(struct rv_monitor *mon)
-{
-	lockdep_assert_held(&rv_interface_lock);
-	mon->reactor->counter--;
-	WARN_ON_ONCE(mon->reactor->counter < 0);
-}
-
 /*
  * Nop reactor register
  */
-- 
2.39.5

[PATCH v3 5/5] rv: Remove struct rv_monitor::reacting

[Nam Cao]

The field 'reacting' in struct rv_monitor is set but never used. Delete it.

Reviewed-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Nam Cao <namcao@linutronix.de>
---
 include/linux/rv.h            |  1 -
 kernel/trace/rv/rv_reactors.c | 19 +++++--------------
 2 files changed, 5 insertions(+), 15 deletions(-)

diff --git a/include/linux/rv.h b/include/linux/rv.h
index 2f867d6f72ba..80731242fe60 100644
--- a/include/linux/rv.h
+++ b/include/linux/rv.h
@@ -104,7 +104,6 @@ struct rv_monitor {
 #ifdef CONFIG_RV_REACTORS
 	struct rv_reactor	*reactor;
 	__printf(1, 2) void	(*react)(const char *msg, ...);
-	bool			reacting;
 #endif
 	struct list_head	list;
 	struct rv_monitor	*parent;
diff --git a/kernel/trace/rv/rv_reactors.c b/kernel/trace/rv/rv_reactors.c
index a8e849e6cd85..106f2c4740f2 100644
--- a/kernel/trace/rv/rv_reactors.c
+++ b/kernel/trace/rv/rv_reactors.c
@@ -160,7 +160,7 @@ static const struct seq_operations monitor_reactors_seq_ops = {
 
 static void monitor_swap_reactors_single(struct rv_monitor *mon,
 					 struct rv_reactor *reactor,
-					 bool reacting, bool nested)
+					 bool nested)
 {
 	bool monitor_enabled;
 
@@ -173,7 +173,6 @@ static void monitor_swap_reactors_single(struct rv_monitor *mon,
 		rv_disable_monitor(mon);
 
 	mon->reactor = reactor;
-	mon->reacting = reacting;
 	mon->react = reactor->react;
 
 	/* enable only once if iterating through a container */
@@ -181,8 +180,7 @@ static void monitor_swap_reactors_single(struct rv_monitor *mon,
 		rv_enable_monitor(mon);
 }
 
-static void monitor_swap_reactors(struct rv_monitor *mon,
-				  struct rv_reactor *reactor, bool reacting)
+static void monitor_swap_reactors(struct rv_monitor *mon, struct rv_reactor *reactor)
 {
 	struct rv_monitor *p = mon;
 
@@ -190,7 +188,7 @@ static void monitor_swap_reactors(struct rv_monitor *mon,
 		list_for_each_entry_continue(p, &rv_monitors_list, list) {
 			if (p->parent != mon)
 				break;
-			monitor_swap_reactors_single(p, reactor, reacting, true);
+			monitor_swap_reactors_single(p, reactor, true);
 		}
 	/*
 	 * This call enables and disables the monitor if they were active.
@@ -198,7 +196,7 @@ static void monitor_swap_reactors(struct rv_monitor *mon,
 	 * All nested monitors are enabled also if they were off, we may refine
 	 * this logic in the future.
 	 */
-	monitor_swap_reactors_single(mon, reactor, reacting, false);
+	monitor_swap_reactors_single(mon, reactor, false);
 }
 
 static ssize_t
@@ -210,7 +208,6 @@ monitor_reactors_write(struct file *file, const char __user *user_buf,
 	struct rv_reactor *reactor;
 	struct seq_file *seq_f;
 	int retval = -EINVAL;
-	bool enable;
 	char *ptr;
 	int len;
 
@@ -243,12 +240,7 @@ monitor_reactors_write(struct file *file, const char __user *user_buf,
 		if (strcmp(ptr, reactor->name) != 0)
 			continue;
 
-		if (strcmp(reactor->name, "nop"))
-			enable = false;
-		else
-			enable = true;
-
-		monitor_swap_reactors(mon, reactor, enable);
+		monitor_swap_reactors(mon, reactor);
 
 		retval = count;
 		break;
@@ -439,7 +431,6 @@ int reactor_populate_monitor(struct rv_monitor *mon)
 	 * Configure as the rv_nop reactor.
 	 */
 	mon->reactor = get_reactor_rdef_by_name("nop");
-	mon->reacting = false;
 
 	return 0;
 }
-- 
2.39.5