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Message-Id: <1616751898-58393-2-git-send-email-xlpang@linux.alibaba.com>
Date: Fri, 26 Mar 2021 17:44:55 +0800
From: Xunlei Pang <xlpang@...ux.alibaba.com>
To: Andrew Morton <akpm@...ux-foundation.org>,
Alexander Duyck <alexander.h.duyck@...ux.intel.com>,
Mel Gorman <mgorman@...hsingularity.net>
Cc: linux-kernel@...r.kernel.org, linux-mm@...ck.org,
Xunlei Pang <xlpang@...ux.alibaba.com>
Subject: [PATCH 1/4] mm/page_reporting: Introduce free page reported counters
It's useful to know how many memory has been actually reported,
so add new zone::reported_pages to record that.
Add "/sys/kernel/mm/page_reporting/reported_kbytes" for the
actual memory has been reported.
Add "/sys/kernel/mm/page_reporting/refault_kbytes" for the
accumulated memory has refaulted in after been reported out.
Signed-off-by: Xunlei Pang <xlpang@...ux.alibaba.com>
---
include/linux/mmzone.h | 3 ++
mm/page_alloc.c | 4 +-
mm/page_reporting.c | 112 +++++++++++++++++++++++++++++++++++++++++++++++--
mm/page_reporting.h | 5 +++
4 files changed, 119 insertions(+), 5 deletions(-)
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 47946ce..ebd169f 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -530,6 +530,9 @@ struct zone {
atomic_long_t managed_pages;
unsigned long spanned_pages;
unsigned long present_pages;
+#ifdef CONFIG_PAGE_REPORTING
+ unsigned long reported_pages;
+#endif
#ifdef CONFIG_CMA
unsigned long cma_pages;
#endif
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 3e4b29ee..c2c5688 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -930,8 +930,10 @@ static inline void del_page_from_free_list(struct page *page, struct zone *zone,
unsigned int order)
{
/* clear reported state and update reported page count */
- if (page_reported(page))
+ if (page_reported(page)) {
__ClearPageReported(page);
+ page_reporting_update_refault(zone, 1 << order);
+ }
list_del(&page->lru);
__ClearPageBuddy(page);
diff --git a/mm/page_reporting.c b/mm/page_reporting.c
index c50d93f..ba195ea 100644
--- a/mm/page_reporting.c
+++ b/mm/page_reporting.c
@@ -1,4 +1,5 @@
// SPDX-License-Identifier: GPL-2.0
+#include <linux/module.h>
#include <linux/mm.h>
#include <linux/mmzone.h>
#include <linux/page_reporting.h>
@@ -19,6 +20,22 @@ enum {
PAGE_REPORTING_ACTIVE
};
+#ifdef CONFIG_SYSFS
+static struct percpu_counter refault_pages;
+
+void page_reporting_update_refault(struct zone *zone, unsigned int pages)
+{
+ zone->reported_pages -= pages;
+ percpu_counter_add_batch(&refault_pages, pages, INT_MAX / 2);
+}
+#else
+void page_reporting_update_refault(struct zone *zone, unsigned int pages)
+{
+ zone->reported_pages -= pages;
+}
+#endif
+
+
/* request page reporting */
static void
__page_reporting_request(struct page_reporting_dev_info *prdev)
@@ -66,7 +83,8 @@ void __page_reporting_notify(void)
static void
page_reporting_drain(struct page_reporting_dev_info *prdev,
- struct scatterlist *sgl, unsigned int nents, bool reported)
+ struct scatterlist *sgl, struct zone *zone,
+ unsigned int nents, bool reported)
{
struct scatterlist *sg = sgl;
@@ -92,8 +110,10 @@ void __page_reporting_notify(void)
* report on the new larger page when we make our way
* up to that higher order.
*/
- if (PageBuddy(page) && buddy_order(page) == order)
+ if (PageBuddy(page) && buddy_order(page) == order) {
__SetPageReported(page);
+ zone->reported_pages += (1 << order);
+ }
} while ((sg = sg_next(sg)));
/* reinitialize scatterlist now that it is empty */
@@ -197,7 +217,7 @@ void __page_reporting_notify(void)
spin_lock_irq(&zone->lock);
/* flush reported pages from the sg list */
- page_reporting_drain(prdev, sgl, PAGE_REPORTING_CAPACITY, !err);
+ page_reporting_drain(prdev, sgl, zone, PAGE_REPORTING_CAPACITY, !err);
/*
* Reset next to first entry, the old next isn't valid
@@ -260,7 +280,7 @@ void __page_reporting_notify(void)
/* flush any remaining pages out from the last report */
spin_lock_irq(&zone->lock);
- page_reporting_drain(prdev, sgl, leftover, !err);
+ page_reporting_drain(prdev, sgl, zone, leftover, !err);
spin_unlock_irq(&zone->lock);
}
@@ -362,3 +382,87 @@ void page_reporting_unregister(struct page_reporting_dev_info *prdev)
mutex_unlock(&page_reporting_mutex);
}
EXPORT_SYMBOL_GPL(page_reporting_unregister);
+
+#ifdef CONFIG_SYSFS
+#define REPORTING_ATTR(_name) \
+ static struct kobj_attribute _name##_attr = \
+ __ATTR(_name, 0644, _name##_show, _name##_store)
+
+static unsigned long get_reported_kbytes(void)
+{
+ struct zone *z;
+ unsigned long nr_reported = 0;
+
+ for_each_populated_zone(z)
+ nr_reported += z->reported_pages;
+
+ return nr_reported << (PAGE_SHIFT - 10);
+}
+
+static ssize_t reported_kbytes_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ return sprintf(buf, "%lu\n", get_reported_kbytes());
+}
+
+static ssize_t reported_kbytes_store(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ const char *buf, size_t count)
+{
+ return -EINVAL;
+}
+REPORTING_ATTR(reported_kbytes);
+
+static u64 get_refault_kbytes(void)
+{
+ u64 sum;
+
+ sum = percpu_counter_sum_positive(&refault_pages);
+ return sum << (PAGE_SHIFT - 10);
+}
+
+static ssize_t refault_kbytes_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ return sprintf(buf, "%llu\n", get_refault_kbytes());
+}
+
+static ssize_t refault_kbytes_store(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ const char *buf, size_t count)
+{
+ return -EINVAL;
+}
+REPORTING_ATTR(refault_kbytes);
+
+static struct attribute *reporting_attrs[] = {
+ &reported_kbytes_attr.attr,
+ &refault_kbytes_attr.attr,
+ NULL,
+};
+
+static struct attribute_group reporting_attr_group = {
+ .attrs = reporting_attrs,
+ .name = "page_reporting",
+};
+#endif
+
+static int __init page_reporting_init(void)
+{
+#ifdef CONFIG_SYSFS
+ int err;
+
+ if (percpu_counter_init(&refault_pages, 0, GFP_KERNEL))
+ panic("Failed to allocate refault_pages percpu counter\n");
+
+ err = sysfs_create_group(mm_kobj, &reporting_attr_group);
+ if (err) {
+ pr_err("%s: Unable to populate sysfs files\n", __func__);
+ return err;
+ }
+#endif
+
+ return 0;
+}
+
+module_init(page_reporting_init);
diff --git a/mm/page_reporting.h b/mm/page_reporting.h
index 2c385dd..19549c7 100644
--- a/mm/page_reporting.h
+++ b/mm/page_reporting.h
@@ -44,11 +44,16 @@ static inline void page_reporting_notify_free(unsigned int order)
/* This will add a few cycles, but should be called infrequently */
__page_reporting_notify();
}
+
+void page_reporting_update_refault(struct zone *zone, unsigned int pages);
#else /* CONFIG_PAGE_REPORTING */
#define page_reported(_page) false
static inline void page_reporting_notify_free(unsigned int order)
{
}
+
+static inline void
+page_reporting_update_refault(struct zone *zone, unsigned int pages) { }
#endif /* CONFIG_PAGE_REPORTING */
#endif /*_MM_PAGE_REPORTING_H */
--
1.8.3.1
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