2bcf887963
Replace pagevecs in putback_lru_pages() and move_active_pages_to_lru() by lists of pages_to_free: then apply Konstantin Khlebnikov's free_hot_cold_page_list() to them instead of pagevec_release(). Which simplifies the flow (no need to drop and retake lock whenever pagevec fills up) and reduces stale addresses in stack backtraces (which often showed through the pagevecs); but more importantly, removes another 120 bytes from the deepest stacks in page reclaim. Although I've not recently seen an actual stack overflow here with a vanilla kernel, move_active_pages_to_lru() has often featured in deep backtraces. However, free_hot_cold_page_list() does not handle compound pages (nor need it: a Transparent HugePage would have been split by the time it reaches the call in shrink_page_list()), but it is possible for putback_lru_pages() or move_active_pages_to_lru() to be left holding the last reference on a THP, so must exclude the unlikely compound case before putting on pages_to_free. Remove pagevec_strip(), its work now done in move_active_pages_to_lru(). The pagevec in scan_mapping_unevictable_pages() remains in mm/vmscan.c, but that is never on the reclaim path, and cannot be replaced by a list. Signed-off-by: Hugh Dickins <hughd@google.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Reviewed-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
99 lines
2.2 KiB
C
99 lines
2.2 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, enum lru_list lru);
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unsigned pagevec_lookup(struct pagevec *pvec, struct address_space *mapping,
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pgoff_t start, unsigned nr_pages);
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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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static inline void __pagevec_lru_add_anon(struct pagevec *pvec)
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{
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____pagevec_lru_add(pvec, LRU_INACTIVE_ANON);
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}
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static inline void __pagevec_lru_add_active_anon(struct pagevec *pvec)
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{
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____pagevec_lru_add(pvec, LRU_ACTIVE_ANON);
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}
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static inline void __pagevec_lru_add_file(struct pagevec *pvec)
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{
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____pagevec_lru_add(pvec, LRU_INACTIVE_FILE);
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}
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static inline void __pagevec_lru_add_active_file(struct pagevec *pvec)
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{
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____pagevec_lru_add(pvec, LRU_ACTIVE_FILE);
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}
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static inline void pagevec_lru_add_file(struct pagevec *pvec)
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{
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if (pagevec_count(pvec))
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__pagevec_lru_add_file(pvec);
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}
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static inline void pagevec_lru_add_anon(struct pagevec *pvec)
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{
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if (pagevec_count(pvec))
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__pagevec_lru_add_anon(pvec);
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}
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#endif /* _LINUX_PAGEVEC_H */
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