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-rw-r--r--include/linux/page-flags.h16
1 files changed, 16 insertions, 0 deletions
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index 77de28bfefb0..222f6f7b2bb3 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -63,6 +63,11 @@
* page_waitqueue(page) is a wait queue of all tasks waiting for the page
* to become unlocked.
*
+ * PG_swapbacked is set when a page uses swap as a backing storage. This are
+ * usually PageAnon or shmem pages but please note that even anonymous pages
+ * might lose their PG_swapbacked flag when they simply can be dropped (e.g. as
+ * a result of MADV_FREE).
+ *
* PG_uptodate tells whether the page's contents is valid. When a read
* completes, the page becomes uptodate, unless a disk I/O error happened.
*
@@ -163,6 +168,9 @@ enum pageflags {
/* non-lru isolated movable page */
PG_isolated = PG_reclaim,
+
+ /* Only valid for buddy pages. Used to track pages that are reported */
+ PG_reported = PG_uptodate,
};
#ifndef __GENERATING_BOUNDS_H
@@ -432,6 +440,14 @@ PAGEFLAG(Idle, idle, PF_ANY)
#endif
/*
+ * PageReported() is used to track reported free pages within the Buddy
+ * allocator. We can use the non-atomic version of the test and set
+ * operations as both should be shielded with the zone lock to prevent
+ * any possible races on the setting or clearing of the bit.
+ */
+__PAGEFLAG(Reported, reported, PF_NO_COMPOUND)
+
+/*
* On an anonymous page mapped into a user virtual memory area,
* page->mapping points to its anon_vma, not to a struct address_space;
* with the PAGE_MAPPING_ANON bit set to distinguish it. See rmap.h.