mm/page_reporting.h

   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 */