/** * release_pages:释放pages页框数组(只有count = 0时,才正真的被回收) */ void release_pages(struct page **pages, int nr, int cold) { int i; struct pagevec pages_to_free; struct zone *zone = NULL; unsigned long uninitialized_var(flags); pagevec_init(&pages_to_free, cold); for (i = 0; i < nr; i++) { struct page *page = pages[i]; if (unlikely(PageCompound(page))) { if (zone) { spin_unlock_irqrestore(&zone->lru_lock, flags); zone = NULL; } put_compound_page(page); continue; } /*减少page的引用次数*/ if (!put_page_testzero(page)) continue; /*page的引用次数为0,则page从zone LRU链表中删除*/ if (PageLRU(page)) { struct zone *pagezone = page_zone(page); if (pagezone != zone) { if (zone) spin_unlock_irqrestore(&zone->lru_lock, flags); zone = pagezone; spin_lock_irqsave(&zone->lru_lock, flags); } VM_BUG_ON(!PageLRU(page)); /*清空页的LRU属性*/ __ClearPageLRU(page); del_page_from_lru(zone, page); } /*page加入到pages_to_free页缓存中*/ if (!pagevec_add(&pages_to_free, page)) { if (zone) { spin_unlock_irqrestore(&zone->lru_lock, flags); zone = NULL; } __pagevec_free(&pages_to_free); pagevec_reinit(&pages_to_free); } } if (zone) spin_unlock_irqrestore(&zone->lru_lock, flags); pagevec_free(&pages_to_free); }
/* * Batched page_cache_release(). Decrement the reference count on all the * passed pages. If it fell to zero then remove the page from the LRU and * free it. * * Avoid taking zone->lru_lock if possible, but if it is taken, retain it * for the remainder of the operation. * * The locking in this function is against shrink_inactive_list(): we recheck * the page count inside the lock to see whether shrink_inactive_list() * grabbed the page via the LRU. If it did, give up: shrink_inactive_list() * will free it. */ void release_pages(struct page **pages, int nr, int cold) { int i; struct pagevec pages_to_free; struct zone *zone = NULL; unsigned long uninitialized_var(flags); pagevec_init(&pages_to_free, cold); for (i = 0; i < nr; i++) { struct page *page = pages[i]; #ifdef CONFIG_OXNAS_FAST_READS_AND_WRITES WARN_ON(PageIncoherentSendfile(page)); #endif // CONFIG_OXNAS_FAST_READS_AND_WRITES if (unlikely(PageCompound(page))) { if (zone) { spin_unlock_irqrestore(&zone->lru_lock, flags); zone = NULL; } put_compound_page(page); continue; } if (!put_page_testzero(page)) continue; if (PageLRU(page)) { struct zone *pagezone = page_zone(page); if (pagezone != zone) { if (zone) spin_unlock_irqrestore(&zone->lru_lock, flags); zone = pagezone; spin_lock_irqsave(&zone->lru_lock, flags); } VM_BUG_ON(!PageLRU(page)); __ClearPageLRU(page); del_page_from_lru(zone, page); } if (!pagevec_add(&pages_to_free, page)) { if (zone) { spin_unlock_irqrestore(&zone->lru_lock, flags); zone = NULL; } __pagevec_free(&pages_to_free); pagevec_reinit(&pages_to_free); } } if (zone) spin_unlock_irqrestore(&zone->lru_lock, flags); pagevec_free(&pages_to_free); }
/* * Batched page_cache_release(). Decrement the reference count on all the * passed pages. If it fell to zero then remove the page from the LRU and * free it. * * Avoid taking zone->lru_lock if possible, but if it is taken, retain it * for the remainder of the operation. * * The locking in this function is against shrink_inactive_list(): we recheck * the page count inside the lock to see whether shrink_inactive_list() * grabbed the page via the LRU. If it did, give up: shrink_inactive_list() * will free it. */ void release_pages(struct page **pages, int nr, int cold) { int i; struct pagevec pages_to_free; struct zone *zone = NULL; unsigned long uninitialized_var(flags); pagevec_init(&pages_to_free, cold); for (i = 0; i < nr; i++) { struct page *page = pages[i]; if (unlikely(PageCompound(page))) { if (zone) { spin_unlock_irqrestore(&zone->lru_lock, flags); zone = NULL; } put_compound_page(page); continue; } if (!put_page_testzero(page)) continue; if (PageLRU(page)) { struct zone *pagezone = page_zone(page); if (pagezone != zone) { if (zone) spin_unlock_irqrestore(&zone->lru_lock, flags); zone = pagezone; spin_lock_irqsave(&zone->lru_lock, flags); } VM_BUG_ON(!PageLRU(page)); __ClearPageLRU(page); del_page_from_lru(zone, page); } else if (PageIONBacked(page)) { ClearPageActive(page); ClearPageUnevictable(page); } if (!pagevec_add(&pages_to_free, page)) { if (zone) { spin_unlock_irqrestore(&zone->lru_lock, flags); zone = NULL; } __pagevec_free(&pages_to_free); pagevec_reinit(&pages_to_free); } } if (zone) spin_unlock_irqrestore(&zone->lru_lock, flags); pagevec_free(&pages_to_free); }
/* * Batched page_cache_release(). Decrement the reference count on all the * passed pages. If it fell to zero then remove the page from the LRU and * free it. * * Avoid taking zone->lru_lock if possible, but if it is taken, retain it * for the remainder of the operation. * * The locking in this function is against shrink_cache(): we recheck the * page count inside the lock to see whether shrink_cache grabbed the page * via the LRU. If it did, give up: shrink_cache will free it. */ void release_pages(struct page **pages, int nr, int cold) { int i; struct pagevec pages_to_free; struct zone *zone = NULL; unsigned long uninitialized_var(flags); pagevec_init(&pages_to_free, cold); for (i = 0; i < nr; i++) { struct page *page = pages[i]; if (unlikely(PageCompound(page))) { if (zone) { spin_unlock_irqrestore(&zone->lru_lock, flags); zone = NULL; } put_compound_page(page); continue; } // dyc: if page->ref not zero, continue if (!put_page_testzero(page)) continue; // dyc: if in url, remove from it if (PageLRU(page)) { struct zone *pagezone = page_zone(page); if (pagezone != zone) { if (zone) spin_unlock_irqrestore(&zone->lru_lock, flags); zone = pagezone; spin_lock_irqsave(&zone->lru_lock, flags); } VM_BUG_ON(!PageLRU(page)); __ClearPageLRU(page); del_page_from_lru(zone, page); } // dyc: if no space available after adding if (!pagevec_add(&pages_to_free, page)) { if (zone) { spin_unlock_irqrestore(&zone->lru_lock, flags); zone = NULL; } // dyc: return page to buddy system __pagevec_free(&pages_to_free); pagevec_reinit(&pages_to_free); } } // for (i = 0; i < nr; i++) if (zone) spin_unlock_irqrestore(&zone->lru_lock, flags); pagevec_free(&pages_to_free); }
/* * Batched page_cache_release(). Decrement the reference count on all the * passed pages. If it fell to zero then remove the page from the LRU and * free it. * * Avoid taking zone->lru_lock if possible, but if it is taken, retain it * for the remainder of the operation. * * The locking in this function is against shrink_cache(): we recheck the * page count inside the lock to see whether shrink_cache grabbed the page * via the LRU. If it did, give up: shrink_cache will free it. */ void release_pages(struct page **pages, int nr, int cold) { int i; struct pagevec pages_to_free; struct zone *zone = NULL; pagevec_init(&pages_to_free, cold); for (i = 0; i < nr; i++) { struct page *page = pages[i]; struct zone *pagezone; if (unlikely(PageCompound(page))) { if (zone) { spin_unlock_irq(&zone->lru_lock); zone = NULL; } put_compound_page(page); continue; } if (!put_page_testzero(page)) continue; pagezone = page_zone(page); if (pagezone != zone) { if (zone) spin_unlock_irq(&zone->lru_lock); zone = pagezone; spin_lock_irq(&zone->lru_lock); } if (TestClearPageLRU(page)) del_page_from_lru(zone, page); if (page_count(page) == 0) { if (!pagevec_add(&pages_to_free, page)) { spin_unlock_irq(&zone->lru_lock); __pagevec_free(&pages_to_free); pagevec_reinit(&pages_to_free); zone = NULL; /* No lock is held */ } } } if (zone) spin_unlock_irq(&zone->lru_lock); pagevec_free(&pages_to_free); }