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b947cee4b9
Implement a variant of find_get_pages() that stops iterating at given index. This may be substantial performance gain if the mapping is sparse. See following commit for details. Furthermore lots of users of this function (through pagevec_lookup()) actually want a range lookup and all of them are currently open-coding this. Also create corresponding pagevec_lookup_range() function. Link: http://lkml.kernel.org/r/20170726114704.7626-4-jack@suse.cz Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
81 lines
2 KiB
C
81 lines
2 KiB
C
/*
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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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/* 14 pointers + two long's align the pagevec structure to a power of two */
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#define PAGEVEC_SIZE 14
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struct page;
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struct address_space;
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struct pagevec {
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unsigned long nr;
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unsigned long cold;
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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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void __pagevec_lru_add(struct pagevec *pvec);
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unsigned pagevec_lookup_entries(struct pagevec *pvec,
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struct address_space *mapping,
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pgoff_t start, unsigned nr_entries,
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pgoff_t *indices);
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void pagevec_remove_exceptionals(struct pagevec *pvec);
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unsigned pagevec_lookup_range(struct pagevec *pvec,
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struct address_space *mapping,
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pgoff_t *start, pgoff_t end, unsigned nr_pages);
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static inline unsigned pagevec_lookup(struct pagevec *pvec,
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struct address_space *mapping,
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pgoff_t *start, unsigned nr_pages)
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{
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return pagevec_lookup_range(pvec, mapping, start, (pgoff_t)-1,
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nr_pages);
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}
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unsigned pagevec_lookup_tag(struct pagevec *pvec,
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struct address_space *mapping, pgoff_t *index, int tag,
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unsigned nr_pages);
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static inline void pagevec_init(struct pagevec *pvec, int cold)
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{
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pvec->nr = 0;
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pvec->cold = cold;
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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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#endif /* _LINUX_PAGEVEC_H */
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