Messages in this thread Patch in this message | | | From | Christoph Hellwig <> | Subject | [PATCH 10/14] pagevec: Add ability to iterate a queue | Date | Mon, 12 Feb 2024 08:13:44 +0100 |
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From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Add a loop counter inside the folio_batch to let us iterate from 0-nr instead of decrementing nr and treating the batch as a stack. It would generate some very weird and suboptimal I/O patterns for page writeback to iterate over the batch as a stack.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Jan Kara <jack@suse.cz> Acked-by: Dave Chinner <dchinner@redhat.com> --- include/linux/pagevec.h | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+)
diff --git a/include/linux/pagevec.h b/include/linux/pagevec.h index 87cc678adc850b..fcc06c300a72c3 100644 --- a/include/linux/pagevec.h +++ b/include/linux/pagevec.h @@ -27,6 +27,7 @@ struct folio; */ struct folio_batch { unsigned char nr; + unsigned char i; bool percpu_pvec_drained; struct folio *folios[PAGEVEC_SIZE]; }; @@ -40,12 +41,14 @@ struct folio_batch { static inline void folio_batch_init(struct folio_batch *fbatch) { fbatch->nr = 0; + fbatch->i = 0; fbatch->percpu_pvec_drained = false; } static inline void folio_batch_reinit(struct folio_batch *fbatch) { fbatch->nr = 0; + fbatch->i = 0; } static inline unsigned int folio_batch_count(struct folio_batch *fbatch) @@ -75,6 +78,21 @@ static inline unsigned folio_batch_add(struct folio_batch *fbatch, return folio_batch_space(fbatch); } +/** + * folio_batch_next - Return the next folio to process. + * @fbatch: The folio batch being processed. + * + * Use this function to implement a queue of folios. + * + * Return: The next folio in the queue, or NULL if the queue is empty. + */ +static inline struct folio *folio_batch_next(struct folio_batch *fbatch) +{ + if (fbatch->i == fbatch->nr) + return NULL; + return fbatch->folios[fbatch->i++]; +} + void __folio_batch_release(struct folio_batch *pvec); static inline void folio_batch_release(struct folio_batch *fbatch) -- 2.39.2
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