xref: /linux/mm/page_reporting.h (revision d195c39052d1da278a00a6744ce59c383b67b191)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _MM_PAGE_REPORTING_H
3 #define _MM_PAGE_REPORTING_H
4 
5 #include <linux/mmzone.h>
6 #include <linux/pageblock-flags.h>
7 #include <linux/page-isolation.h>
8 #include <linux/jump_label.h>
9 #include <linux/slab.h>
10 #include <asm/pgtable.h>
11 #include <linux/scatterlist.h>
12 
13 #define PAGE_REPORTING_MIN_ORDER	pageblock_order
14 
15 #ifdef CONFIG_PAGE_REPORTING
16 DECLARE_STATIC_KEY_FALSE(page_reporting_enabled);
17 void __page_reporting_notify(void);
18 
19 static inline bool page_reported(struct page *page)
20 {
21 	return static_branch_unlikely(&page_reporting_enabled) &&
22 	       PageReported(page);
23 }
24 
25 /**
26  * page_reporting_notify_free - Free page notification to start page processing
27  *
28  * This function is meant to act as a screener for __page_reporting_notify
29  * which will determine if a give zone has crossed over the high-water mark
30  * that will justify us beginning page treatment. If we have crossed that
31  * threshold then it will start the process of pulling some pages and
32  * placing them in the batch list for treatment.
33  */
34 static inline void page_reporting_notify_free(unsigned int order)
35 {
36 	/* Called from hot path in __free_one_page() */
37 	if (!static_branch_unlikely(&page_reporting_enabled))
38 		return;
39 
40 	/* Determine if we have crossed reporting threshold */
41 	if (order < PAGE_REPORTING_MIN_ORDER)
42 		return;
43 
44 	/* This will add a few cycles, but should be called infrequently */
45 	__page_reporting_notify();
46 }
47 #else /* CONFIG_PAGE_REPORTING */
48 #define page_reported(_page)	false
49 
50 static inline void page_reporting_notify_free(unsigned int order)
51 {
52 }
53 #endif /* CONFIG_PAGE_REPORTING */
54 #endif /*_MM_PAGE_REPORTING_H */
55