The patch titled
Subject: mm,page_owner: filter out stacks by a threshold
has been added to the -mm mm-unstable branch. Its filename is
mmpage_owner-filter-out-stacks-by-a-threshold.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.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
Date: Wed, 14 Feb 2024 18:01:56 +0100
We want to be able to filter out the stacks based on a threshold we can
can tune. By writing to 'count_threshold' file, we can adjust the
threshold value.
Link: https://lkml.kernel.org/r/20240214170157.17530-7-osalvador@xxxxxxx
Signed-off-by: Oscar Salvador <osalvador@xxxxxxx>
Cc: Alexander Potapenko <glider@xxxxxxxxxx>
Cc: Andrey Konovalov <andreyknvl@xxxxxxxxx>
Cc: Marco Elver <elver@xxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/page_owner.c | 29 +++++++++++++++++++++++++----
1 file changed, 25 insertions(+), 4 deletions(-)
--- a/mm/page_owner.c~mmpage_owner-filter-out-stacks-by-a-threshold
+++ a/mm/page_owner.c
@@ -846,9 +846,11 @@ static void *stack_next(struct seq_file
return stack;
}
+static unsigned long page_owner_stack_threshold;
+
static int stack_print(struct seq_file *m, void *v)
{
- int i;
+ int i, stack_count;
struct stack *stack = v;
unsigned long *entries;
unsigned long nr_entries;
@@ -856,14 +858,15 @@ static int stack_print(struct seq_file *
nr_entries = stack_record->size;
entries = stack_record->entries;
+ stack_count = refcount_read(&stack_record->count);
- if (!nr_entries || nr_entries < 0 ||
- refcount_read(&stack_record->count) < 2)
+ if (!nr_entries || nr_entries < 0 || stack_count < 2 ||
+ stack_count < page_owner_stack_threshold)
return 0;
for (i = 0; i < nr_entries; i++)
seq_printf(m, " %pS\n", (void *)entries[i]);
- seq_printf(m, "stack_count: %d\n\n", refcount_read(&stack_record->count));
+ seq_printf(m, "stack_count: %d\n\n", stack_count);
return 0;
}
@@ -891,6 +894,22 @@ static const struct file_operations page
.release = seq_release,
};
+static int page_owner_threshold_get(void *data, u64 *val)
+{
+ *val = READ_ONCE(page_owner_stack_threshold);
+ return 0;
+}
+
+static int page_owner_threshold_set(void *data, u64 val)
+{
+ WRITE_ONCE(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)
{
struct dentry *dir;
@@ -905,6 +924,8 @@ static int __init pageowner_init(void)
dir = debugfs_create_dir("page_owner_stacks", NULL);
debugfs_create_file("show_stacks", 0400, dir, NULL,
&page_owner_stack_operations);
+ debugfs_create_file("count_threshold", 0600, dir, NULL,
+ &proc_page_owner_threshold);
return 0;
}
_
Patches currently in -mm which might be from osalvador@xxxxxxx are
lib-stackdepot-fix-first-entry-having-a-0-handle.patch
lib-stackdepot-move-stack_record-struct-definition-into-the-header.patch
mmpage_owner-maintain-own-list-of-stack_records-structs.patch
mmpage_owner-implement-the-tracking-of-the-stacks-count.patch
mmpage_owner-display-all-stacks-and-their-count.patch
mmpage_owner-filter-out-stacks-by-a-threshold.patch
mmpage_owner-update-documentation-regarding-page_owner_stacks.patch
