From f9004dbfff8a3fbbd7e2a88c8a4327c7f2f8e5b2 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Wed, 31 Jan 2024 01:04:47 +0000
Subject: [PATCH] add driver 5G
---
kernel/include/linux/balloon_compaction.h | 53 +++++++++++++++++------------------------------------
1 files changed, 17 insertions(+), 36 deletions(-)
diff --git a/kernel/include/linux/balloon_compaction.h b/kernel/include/linux/balloon_compaction.h
index 53051f3..338aa27 100644
--- a/kernel/include/linux/balloon_compaction.h
+++ b/kernel/include/linux/balloon_compaction.h
@@ -4,15 +4,18 @@
*
* Common interface definitions for making balloon pages movable by compaction.
*
- * Despite being perfectly possible to perform ballooned pages migration, they
- * make a special corner case to compaction scans because balloon pages are not
- * enlisted at any LRU list like the other pages we do compact / migrate.
+ * Balloon page migration makes use of the general non-lru movable page
+ * feature.
+ *
+ * page->private is used to reference the responsible balloon device.
+ * page->mapping is used in context of non-lru page migration to reference
+ * the address space operations for page isolation/migration/compaction.
*
* As the page isolation scanning step a compaction thread does is a lockless
* procedure (from a page standpoint), it might bring some racy situations while
* performing balloon page compaction. In order to sort out these racy scenarios
* and safely perform balloon's page compaction and migration we must, always,
- * ensure following these three simple rules:
+ * ensure following these simple rules:
*
* i. when updating a balloon's page ->mapping element, strictly do it under
* the following lock order, independently of the far superior
@@ -21,19 +24,8 @@
* +--spin_lock_irq(&b_dev_info->pages_lock);
* ... page->mapping updates here ...
*
- * ii. before isolating or dequeueing a balloon page from the balloon device
- * pages list, the page reference counter must be raised by one and the
- * extra refcount must be dropped when the page is enqueued back into
- * the balloon device page list, thus a balloon page keeps its reference
- * counter raised only while it is under our special handling;
- *
- * iii. after the lockless scan step have selected a potential balloon page for
- * isolation, re-test the PageBalloon mark and the PagePrivate flag
- * under the proper page lock, to ensure isolating a valid balloon page
- * (not yet isolated, nor under release procedure)
- *
- * iv. isolation or dequeueing procedure must clear PagePrivate flag under
- * page lock together with removing page from balloon device page list.
+ * ii. isolation or dequeueing procedure must remove the page from balloon
+ * device page list under b_dev_info->pages_lock.
*
* The functions provided by this interface are placed to help on coping with
* the aforementioned balloon page corner case, as well as to ensure the simple
@@ -72,6 +64,10 @@
extern void balloon_page_enqueue(struct balloon_dev_info *b_dev_info,
struct page *page);
extern struct page *balloon_page_dequeue(struct balloon_dev_info *b_dev_info);
+extern size_t balloon_page_list_enqueue(struct balloon_dev_info *b_dev_info,
+ struct list_head *pages);
+extern size_t balloon_page_list_dequeue(struct balloon_dev_info *b_dev_info,
+ struct list_head *pages, size_t n_req_pages);
static inline void balloon_devinfo_init(struct balloon_dev_info *balloon)
{
@@ -103,7 +99,7 @@
static inline void balloon_page_insert(struct balloon_dev_info *balloon,
struct page *page)
{
- __SetPageBalloon(page);
+ __SetPageOffline(page);
__SetPageMovable(page, balloon->inode->i_mapping);
set_page_private(page, (unsigned long)balloon);
list_add(&page->lru, &balloon->pages);
@@ -119,7 +115,7 @@
*/
static inline void balloon_page_delete(struct page *page)
{
- __ClearPageBalloon(page);
+ __ClearPageOffline(page);
__ClearPageMovable(page);
set_page_private(page, 0);
/*
@@ -149,29 +145,14 @@
static inline void balloon_page_insert(struct balloon_dev_info *balloon,
struct page *page)
{
- __SetPageBalloon(page);
+ __SetPageOffline(page);
list_add(&page->lru, &balloon->pages);
}
static inline void balloon_page_delete(struct page *page)
{
- __ClearPageBalloon(page);
+ __ClearPageOffline(page);
list_del(&page->lru);
-}
-
-static inline bool __is_movable_balloon_page(struct page *page)
-{
- return false;
-}
-
-static inline bool balloon_page_movable(struct page *page)
-{
- return false;
-}
-
-static inline bool isolated_balloon_page(struct page *page)
-{
- return false;
}
static inline bool balloon_page_isolate(struct page *page)
--
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