| Message ID | 20231218153553.807799-11-hch@lst.de (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [01/17] writeback: fix done_index when hitting the wbc->nr_to_write | expand |
On Mon 18-12-23 16:35:46, Christoph Hellwig wrote: > 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> Looks good. Feel free to add: Reviewed-by: Jan Kara <jack@suse.cz> Honza > --- > 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 >
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)