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139 lines
3.4 KiB
139 lines
3.4 KiB
/* SPDX-License-Identifier: GPL-2.0 */ |
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/* |
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* include/linux/pagevec.h |
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* |
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* In many places it is efficient to batch an operation up against multiple |
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* pages. A pagevec is a multipage container which is used for that. |
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*/ |
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#ifndef _LINUX_PAGEVEC_H |
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#define _LINUX_PAGEVEC_H |
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#include <linux/xarray.h> |
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/* 15 pointers + header align the pagevec structure to a power of two */ |
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#define PAGEVEC_SIZE 15 |
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struct page; |
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struct folio; |
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struct address_space; |
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/* Layout must match folio_batch */ |
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struct pagevec { |
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unsigned char nr; |
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bool percpu_pvec_drained; |
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struct page *pages[PAGEVEC_SIZE]; |
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}; |
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void __pagevec_release(struct pagevec *pvec); |
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unsigned pagevec_lookup_range_tag(struct pagevec *pvec, |
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struct address_space *mapping, pgoff_t *index, pgoff_t end, |
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xa_mark_t tag); |
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static inline unsigned pagevec_lookup_tag(struct pagevec *pvec, |
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struct address_space *mapping, pgoff_t *index, xa_mark_t tag) |
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{ |
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return pagevec_lookup_range_tag(pvec, mapping, index, (pgoff_t)-1, tag); |
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} |
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static inline void pagevec_init(struct pagevec *pvec) |
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{ |
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pvec->nr = 0; |
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pvec->percpu_pvec_drained = false; |
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} |
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static inline void pagevec_reinit(struct pagevec *pvec) |
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{ |
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pvec->nr = 0; |
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} |
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static inline unsigned pagevec_count(struct pagevec *pvec) |
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{ |
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return pvec->nr; |
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} |
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static inline unsigned pagevec_space(struct pagevec *pvec) |
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{ |
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return PAGEVEC_SIZE - pvec->nr; |
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} |
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/* |
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* Add a page to a pagevec. Returns the number of slots still available. |
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*/ |
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static inline unsigned pagevec_add(struct pagevec *pvec, struct page *page) |
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{ |
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pvec->pages[pvec->nr++] = page; |
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return pagevec_space(pvec); |
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} |
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static inline void pagevec_release(struct pagevec *pvec) |
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{ |
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if (pagevec_count(pvec)) |
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__pagevec_release(pvec); |
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} |
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/** |
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* struct folio_batch - A collection of folios. |
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* |
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* The folio_batch is used to amortise the cost of retrieving and |
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* operating on a set of folios. The order of folios in the batch may be |
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* significant (eg delete_from_page_cache_batch()). Some users of the |
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* folio_batch store "exceptional" entries in it which can be removed |
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* by calling folio_batch_remove_exceptionals(). |
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*/ |
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struct folio_batch { |
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unsigned char nr; |
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bool percpu_pvec_drained; |
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struct folio *folios[PAGEVEC_SIZE]; |
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}; |
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/* Layout must match pagevec */ |
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static_assert(sizeof(struct pagevec) == sizeof(struct folio_batch)); |
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static_assert(offsetof(struct pagevec, pages) == |
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offsetof(struct folio_batch, folios)); |
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/** |
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* folio_batch_init() - Initialise a batch of folios |
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* @fbatch: The folio batch. |
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* |
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* A freshly initialised folio_batch contains zero folios. |
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*/ |
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static inline void folio_batch_init(struct folio_batch *fbatch) |
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{ |
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fbatch->nr = 0; |
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fbatch->percpu_pvec_drained = false; |
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} |
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static inline unsigned int folio_batch_count(struct folio_batch *fbatch) |
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{ |
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return fbatch->nr; |
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} |
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static inline unsigned int fbatch_space(struct folio_batch *fbatch) |
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{ |
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return PAGEVEC_SIZE - fbatch->nr; |
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} |
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/** |
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* folio_batch_add() - Add a folio to a batch. |
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* @fbatch: The folio batch. |
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* @folio: The folio to add. |
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* |
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* The folio is added to the end of the batch. |
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* The batch must have previously been initialised using folio_batch_init(). |
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* |
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* Return: The number of slots still available. |
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*/ |
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static inline unsigned folio_batch_add(struct folio_batch *fbatch, |
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struct folio *folio) |
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{ |
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fbatch->folios[fbatch->nr++] = folio; |
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return fbatch_space(fbatch); |
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} |
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static inline void folio_batch_release(struct folio_batch *fbatch) |
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{ |
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pagevec_release((struct pagevec *)fbatch); |
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} |
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void folio_batch_remove_exceptionals(struct folio_batch *fbatch); |
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#endif /* _LINUX_PAGEVEC_H */
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