We want to be able to filter out the output on a threshold basis,
in this way we can get rid of a lot of noise and focus only on those
stacks which have an allegedly high counter.
We can control the threshold value by a new file called
'page_owner_threshold', which is 0 by default.
Signed-off-by: Oscar Salvador <[email protected]>
---
include/linux/stackdepot.h | 3 +++
lib/stackdepot.c | 17 ++++++++++++++++-
mm/page_owner.c | 5 +++++
3 files changed, 24 insertions(+), 1 deletion(-)
diff --git a/include/linux/stackdepot.h b/include/linux/stackdepot.h
index ca048a79bf7c..c998b8024534 100644
--- a/include/linux/stackdepot.h
+++ b/include/linux/stackdepot.h
@@ -70,6 +70,9 @@ depot_stack_handle_t stack_depot_save_action(unsigned long *entries,
void *stack_start(struct seq_file *m, loff_t *ppos);
void *stack_next(struct seq_file *m, void *v, loff_t *ppos);
int stack_print(struct seq_file *m, void *v);
+
+int page_owner_threshold_get(void *data, u64 *val);
+int page_owner_threshold_set(void *data, u64 val);
#endif
unsigned int stack_depot_fetch(depot_stack_handle_t handle,
diff --git a/lib/stackdepot.c b/lib/stackdepot.c
index 97e5dce40f4b..b70d081d7c61 100644
--- a/lib/stackdepot.c
+++ b/lib/stackdepot.c
@@ -569,6 +569,9 @@ depot_stack_handle_t stack_depot_save_action(unsigned long *entries,
EXPORT_SYMBOL_GPL(stack_depot_save_action);
#ifdef CONFIG_PAGE_OWNER
+
+static unsigned long page_owner_stack_threshold = 0;
+
void *stack_start(struct seq_file *m, loff_t *ppos)
{
unsigned long *table = m->private;
@@ -624,7 +627,7 @@ int stack_print(struct seq_file *m, void *v)
if (!stack->size || stack->size < 0 ||
stack->size > PAGE_SIZE || stack->handle.valid != 1 ||
- refcount_read(&stack->count) < 1)
+ refcount_read(&stack->count) < page_owner_stack_threshold)
return 0;
buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
@@ -637,4 +640,16 @@ int stack_print(struct seq_file *m, void *v)
return 0;
}
+
+int page_owner_threshold_get(void *data, u64 *val)
+{
+ *val = page_owner_stack_threshold;
+ return 0;
+}
+
+int page_owner_threshold_set(void *data, u64 val)
+{
+ page_owner_stack_threshold = val;
+ return 0;
+}
#endif
diff --git a/mm/page_owner.c b/mm/page_owner.c
index 3808c0985060..3e05ebd25ba0 100644
--- a/mm/page_owner.c
+++ b/mm/page_owner.c
@@ -694,6 +694,9 @@ const struct file_operations page_owner_stack_operations = {
.release = seq_release,
};
+DEFINE_SIMPLE_ATTRIBUTE(proc_page_owner_threshold, &page_owner_threshold_get,
+ &page_owner_threshold_set, "%lu");
+
static int __init pageowner_init(void)
{
if (!static_branch_unlikely(&page_owner_inited)) {
@@ -706,6 +709,8 @@ static int __init pageowner_init(void)
debugfs_create_file("page_owner_stacks", S_IRUSR, NULL, NULL,
&page_owner_stack_operations);
+ debugfs_create_file("page_owner_threshold", 0600, NULL, NULL,
+ &proc_page_owner_threshold);
return 0;
}
--
2.35.3