The patch titled
Subject: mm,page_owner: filter out stacks by a threshold counter
has been added to the -mm mm-unstable branch. Its filename is
mmpage_owner-filter-out-stacks-by-a-threshold-counter.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mmpage_owner-filter-out-stacks-by-a-threshold-counter.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Oscar Salvador <osalvador@xxxxxxx>
Subject: mm,page_owner: filter out stacks by a threshold counter
Date: Tue, 16 May 2023 20:25:37 +0200
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.
Link: https://lkml.kernel.org/r/20230516182537.3139-4-osalvador@xxxxxxx
Signed-off-by: Oscar Salvador <osalvador@xxxxxxx>
Cc: Alexander Potapenko <glider@xxxxxxxxxx>
Cc: Andrey Konovalov <andreyknvl@xxxxxxxxx>
Cc: Eric Dumazet <edumazet@xxxxxxxxxx>
Cc: Marco Elver <elver@xxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Waiman Long <longman@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
lib/stackdepot.c | 5 ++++-
mm/page_owner.c | 21 +++++++++++++++++++++
2 files changed, 25 insertions(+), 1 deletion(-)
--- a/lib/stackdepot.c~mmpage_owner-filter-out-stacks-by-a-threshold-counter
+++ a/lib/stackdepot.c
@@ -488,6 +488,9 @@ static struct stack_record *stack_depot_
}
#ifdef CONFIG_PAGE_OWNER
+
+extern unsigned long page_owner_stack_threshold;
+
void *stack_start(struct seq_file *m, loff_t *ppos)
{
unsigned long *table = m->private;
@@ -543,7 +546,7 @@ int stack_print(struct seq_file *m, void
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);
--- a/mm/page_owner.c~mmpage_owner-filter-out-stacks-by-a-threshold-counter
+++ a/mm/page_owner.c
@@ -743,6 +743,23 @@ const struct file_operations page_owner_
.release = seq_release,
};
+unsigned long page_owner_stack_threshold;
+
+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;
+}
+
+DEFINE_SIMPLE_ATTRIBUTE(proc_page_owner_threshold, &page_owner_threshold_get,
+ &page_owner_threshold_set, "%llu");
+
static int __init pageowner_init(void)
{
if (!static_branch_unlikely(&page_owner_inited)) {
@@ -755,6 +772,10 @@ static int __init pageowner_init(void)
debugfs_create_file("page_owner_stacks", 0400, NULL, NULL,
&page_owner_stack_operations);
+ debugfs_create_file("page_owner_threshold", 0600, NULL, NULL,
+ &proc_page_owner_threshold);
+
+ page_owner_stack_threshold = 0;
return 0;
}
_
Patches currently in -mm which might be from osalvador@xxxxxxx are
lib-stackdepot-add-a-refcount-field-in-stack_record.patch
mm-page_owner-add-page_owner_stacks-file-to-print-out-only-stacks-and-their-counte.patch
mmpage_owner-filter-out-stacks-by-a-threshold-counter.patch
