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authorMatthew Wilcox (Oracle) <willy@infradead.org>2021-12-06 23:24:51 +0300
committerMatthew Wilcox (Oracle) <willy@infradead.org>2022-01-03 04:29:02 +0300
commit10331795fb7991a39ebd0330fdb074cbd81fef48 (patch)
tree329162ccef888be45902b3a78f562d058907a720 /include/linux/pagevec.h
parenta229a4f00d1eab3f665b92dc9f8dbceca9b8f49c (diff)
downloadlinux-10331795fb7991a39ebd0330fdb074cbd81fef48.tar.xz
pagevec: Add folio_batch
The folio_batch is the same as the pagevec, except that it is typed to contain folios and not pages. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Diffstat (limited to 'include/linux/pagevec.h')
-rw-r--r--include/linux/pagevec.h69
1 files changed, 69 insertions, 0 deletions
diff --git a/include/linux/pagevec.h b/include/linux/pagevec.h
index 7f3f19065a9f..c3fa616d7ae7 100644
--- a/include/linux/pagevec.h
+++ b/include/linux/pagevec.h
@@ -15,8 +15,10 @@
#define PAGEVEC_SIZE 15
struct page;
+struct folio;
struct address_space;
+/* Layout must match folio_batch */
struct pagevec {
unsigned char nr;
bool percpu_pvec_drained;
@@ -81,4 +83,71 @@ static inline void pagevec_release(struct pagevec *pvec)
__pagevec_release(pvec);
}
+/**
+ * struct folio_batch - A collection of folios.
+ *
+ * The folio_batch is used to amortise the cost of retrieving and
+ * operating on a set of folios. The order of folios in the batch may be
+ * significant (eg delete_from_page_cache_batch()). Some users of the
+ * folio_batch store "exceptional" entries in it which can be removed
+ * by calling folio_batch_remove_exceptionals().
+ */
+struct folio_batch {
+ unsigned char nr;
+ bool percpu_pvec_drained;
+ struct folio *folios[PAGEVEC_SIZE];
+};
+
+/* Layout must match pagevec */
+static_assert(sizeof(struct pagevec) == sizeof(struct folio_batch));
+static_assert(offsetof(struct pagevec, pages) ==
+ offsetof(struct folio_batch, folios));
+
+/**
+ * folio_batch_init() - Initialise a batch of folios
+ * @fbatch: The folio batch.
+ *
+ * A freshly initialised folio_batch contains zero folios.
+ */
+static inline void folio_batch_init(struct folio_batch *fbatch)
+{
+ fbatch->nr = 0;
+}
+
+static inline unsigned int folio_batch_count(struct folio_batch *fbatch)
+{
+ return fbatch->nr;
+}
+
+static inline unsigned int fbatch_space(struct folio_batch *fbatch)
+{
+ return PAGEVEC_SIZE - fbatch->nr;
+}
+
+/**
+ * folio_batch_add() - Add a folio to a batch.
+ * @fbatch: The folio batch.
+ * @folio: The folio to add.
+ *
+ * The folio is added to the end of the batch.
+ * The batch must have previously been initialised using folio_batch_init().
+ *
+ * Return: The number of slots still available.
+ */
+static inline unsigned folio_batch_add(struct folio_batch *fbatch,
+ struct folio *folio)
+{
+ fbatch->folios[fbatch->nr++] = folio;
+ return fbatch_space(fbatch);
+}
+
+static inline void folio_batch_release(struct folio_batch *fbatch)
+{
+ pagevec_release((struct pagevec *)fbatch);
+}
+
+static inline void folio_batch_remove_exceptionals(struct folio_batch *fbatch)
+{
+ pagevec_remove_exceptionals((struct pagevec *)fbatch);
+}
#endif /* _LINUX_PAGEVEC_H */