NR_FILE_PAGES统计哪些内存

babatengwo

各位大侠，问一下zone_stat_item中，NR_FILE_PAGES是对哪些内存的统计？

enum zone_stat_item {
        /* First 128 byte cacheline (assuming 64 bit words) */
        NR_FREE_PAGES,
        NR_LRU_BASE,
        NR_INACTIVE_ANON = NR_LRU_BASE, /* must match order of LRU_[IN]ACTIVE */
        NR_ACTIVE_ANON,                /*  "     "     "   "       "         */
        NR_INACTIVE_FILE,        /*  "     "     "   "       "         */
        NR_ACTIVE_FILE,                /*  "     "     "   "       "         */
        NR_UNEVICTABLE,                /*  "     "     "   "       "         */
        NR_MLOCK,                /* mlock()ed pages found and moved off LRU */
        NR_ANON_PAGES,        /* Mapped anonymous pages */
        NR_FILE_MAPPED,        /* pagecache pages mapped into pagetables.
                           only modified from process context */
        NR_FILE_PAGES,
        NR_FILE_DIRTY,
        NR_WRITEBACK,
        NR_SLAB_RECLAIMABLE,
        ......
}

Tinnal

回复 1# babatengwo

文件使用的page cache的数量。

1. /**
   
2. * add_to_page_cache - add newly allocated pagecache pages
   
3. * @page:        page to add
   
4. * @mapping:        the page's address_space
   
5. * @offset:        page index
   
6. * @gfp_mask:        page allocation mode
   
7. *
   
8. * This function is used to add newly allocated pagecache pages;
   
9. * the page is new, so we can just run SetPageLocked() against it.
   
10. * The other page state flags were set by rmqueue().
    
11. *
    
12. * This function does not add the page to the LRU.  The caller must do that.
    
13. */
    
14. int add_to_page_cache(struct page *page, struct address_space *mapping,
    
15.                 pgoff_t offset, gfp_t gfp_mask)
    
16. {
    
17.         int error = radix_tree_preload(gfp_mask & ~__GFP_HIGHMEM);
    
18. 
    
19.         if (error == 0) {
    
20.                 write_lock_irq(&mapping->tree_lock);
    
21.                 error = radix_tree_insert(&mapping->page_tree, offset, page);
    
22.                 if (!error) {
    
23.                         page_cache_get(page);
    
24.                         SetPageLocked(page);
    
25.                         page->mapping = mapping;
    
26.                         page->index = offset;
    
27.                         mapping->nrpages++;
    
28.                         __inc_zone_page_state(page, NR_FILE_PAGES);
    
29.                 }
    
30.                 write_unlock_irq(&mapping->tree_lock);
    
31.                 radix_tree_preload_end();
    
32.         }
    
33.         return error;
    
34. }

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