From: Oscar Salvador <osalvador@suse.de>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
Michal Hocko <mhocko@suse.com>, Vlastimil Babka <vbabka@suse.cz>,
Eric Dumazet <edumazet@google.com>,
Waiman Long <longman@redhat.com>,
Suren Baghdasaryan <surenb@google.com>,
Oscar Salvador <osalvador@suse.de>
Subject: [PATCH 3/3] mm,page_owner: Filter out stacks by a threshold counter
Date: Thu, 1 Sep 2022 06:42:49 +0200 [thread overview]
Message-ID: <20220901044249.4624-4-osalvador@suse.de> (raw)
In-Reply-To: <20220901044249.4624-1-osalvador@suse.de>
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 <osalvador@suse.de>
---
include/linux/stackdepot.h | 3 +-
lib/stackdepot.c | 6 ++--
mm/page_owner.c | 61 +++++++++++++++++++++++++++++++++++++-
3 files changed, 66 insertions(+), 4 deletions(-)
diff --git a/include/linux/stackdepot.h b/include/linux/stackdepot.h
index 20f62039f23a..ee66be40a152 100644
--- a/include/linux/stackdepot.h
+++ b/include/linux/stackdepot.h
@@ -26,7 +26,8 @@ depot_stack_handle_t __stack_depot_save(unsigned long *entries,
stack_action_t action);
void stack_depot_dec_count(depot_stack_handle_t handle);
int stack_depot_print_stacks_threshold(char *buf, size_t size, loff_t *pos,
- unsigned long *last_stack);
+ unsigned long *last_stack,
+ unsigned long threshold);
/*
* Every user of stack depot has to call stack_depot_init() during its own init
diff --git a/lib/stackdepot.c b/lib/stackdepot.c
index 3090ae0f3958..b4a04f09a7b7 100644
--- a/lib/stackdepot.c
+++ b/lib/stackdepot.c
@@ -528,7 +528,8 @@ depot_stack_handle_t stack_depot_save_action(unsigned long *entries,
EXPORT_SYMBOL_GPL(stack_depot_save_action);
int stack_depot_print_stacks_threshold(char *buf, size_t size, loff_t *pos,
- unsigned long *last_stack)
+ unsigned long *last_stack,
+ unsigned long threshold)
{
struct stack_record *stack = NULL, *last;
struct stack_record **stacks;
@@ -547,7 +548,8 @@ int stack_depot_print_stacks_threshold(char *buf, size_t size, loff_t *pos,
for (; stack; stack = stack->next) {
if (!stack->size || stack->size < 0 ||
stack->size > size || stack->handle.valid != 1 ||
- refcount_read(&stack->count) < 1)
+ refcount_read(&stack->count) < 1 ||
+ refcount_read(&stack->count) < threshold)
continue;
ret += stack_trace_snprint(buf, size, stack->entries, stack->size, 0);
diff --git a/mm/page_owner.c b/mm/page_owner.c
index 8c67c7eb2451..ef10cf44aaec 100644
--- a/mm/page_owner.c
+++ b/mm/page_owner.c
@@ -44,6 +44,7 @@ static depot_stack_handle_t early_handle;
static void init_early_allocated_pages(void);
static unsigned long last_stack = 0;
+static unsigned long threshold_count = 0;
static int __init early_page_owner_param(char *buf)
{
@@ -676,7 +677,8 @@ static ssize_t read_page_owner_stacks(struct file *file, char __user *buf,
if (!kbuf)
return ENOMEM;
- ret += stack_depot_print_stacks_threshold(kbuf, count, pos, &last_stack);
+ ret += stack_depot_print_stacks_threshold(kbuf, count, pos, &last_stack,
+ threshold_count);
if (copy_to_user(buf, kbuf, ret))
ret = -EFAULT;
@@ -687,6 +689,61 @@ static ssize_t read_page_owner_stacks(struct file *file, char __user *buf,
return ret;
}
+static ssize_t read_page_owner_threshold(struct file *file, char __user *buf,
+ size_t count, loff_t *pos)
+{
+ char *kbuf;
+ int ret = 0;
+
+ count = min_t(size_t, count, PAGE_SIZE);
+
+ if (*pos >= count)
+ return 0;
+
+ kbuf = kmalloc(count, GFP_KERNEL);
+ if (!kbuf)
+ return ENOMEM;
+
+ ret = scnprintf(kbuf, count, "%lu\n", threshold_count);
+ if (copy_to_user(buf, kbuf, ret))
+ ret = -EFAULT;
+
+ *pos += count;
+ kfree(kbuf);
+
+ return ret;
+}
+
+static ssize_t write_page_owner_threshold(struct file *file, const char __user *buf,
+ size_t count, loff_t *pos)
+{
+ char *kbuf;
+ int ret = 0;
+
+ count = min_t(size_t, count, PAGE_SIZE);
+ kbuf = kmalloc(count, GFP_KERNEL);
+ if (!kbuf)
+ return -ENOMEM;
+
+ if (copy_from_user(kbuf, buf, count)) {
+ ret = -EFAULT;
+ goto out;
+ }
+
+ kbuf[count - 1] = '\0';
+
+ ret = kstrtoul(kbuf, 10, &threshold_count);
+
+out:
+ kfree(kbuf);
+ return ret ? ret : count;
+}
+
+static const struct file_operations proc_page_owner_threshold = {
+ .read = read_page_owner_threshold,
+ .write = write_page_owner_threshold,
+};
+
static const struct file_operations proc_page_owner_stacks = {
.read = read_page_owner_stacks,
};
@@ -706,6 +763,8 @@ static int __init pageowner_init(void)
&proc_page_owner_operations);
debugfs_create_file("page_owner_stacks", 0400, NULL, NULL,
&proc_page_owner_stacks);
+ debugfs_create_file("page_owner_threshold", 0600, NULL, NULL,
+ &proc_page_owner_threshold);
return 0;
}
--
2.35.3
next prev parent reply other threads:[~2022-09-01 4:43 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-01 4:42 [PATCH 0/3] page_owner: print stacks and their counter Oscar Salvador
2022-09-01 4:42 ` [PATCH 1/3] lib/stackdepot: Add a refcount field in stack_record Oscar Salvador
2022-09-01 8:24 ` Marco Elver
2022-09-01 8:38 ` Michal Hocko
2022-09-01 9:18 ` Marco Elver
2022-09-01 10:01 ` Michal Hocko
2022-09-01 10:20 ` Marco Elver
2022-09-05 20:53 ` Andrey Konovalov
2022-09-02 3:27 ` Oscar Salvador
2022-09-01 4:42 ` [PATCH 2/3] mm, page_owner: Add page_owner_stacks file to print out only stacks and their counter Oscar Salvador
2022-09-01 8:16 ` Ammar Faizi
2022-09-02 3:33 ` Oscar Salvador
2022-09-01 19:29 ` kernel test robot
2022-09-02 0:56 ` kernel test robot
2022-09-01 4:42 ` Oscar Salvador [this message]
2022-09-01 8:31 ` [PATCH 3/3] mm,page_owner: Filter out stacks by a threshold counter Ammar Faizi
2022-09-02 3:36 ` Oscar Salvador
2022-09-01 8:40 ` Michal Hocko
2022-09-02 3:37 ` Oscar Salvador
2022-09-01 8:32 ` [PATCH 0/3] page_owner: print stacks and their counter Michal Hocko
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