Eric Lee / linux-smarc-t335x-v3.2

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include/linux/quicklist.h 2.1 KB
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6225e9373   Christoph Lameter   Quicklists for pa... 
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  #ifndef LINUX_QUICKLIST_H
  #define LINUX_QUICKLIST_H
  /*
   * Fast allocations and disposal of pages. Pages must be in the condition
   * as needed after allocation when they are freed. Per cpu lists of pages
   * are kept that only contain node local pages.
   *
   * (C) 2007, SGI. Christoph Lameter <clameter@sgi.com>
   */
  #include <linux/kernel.h>
  #include <linux/gfp.h>
  #include <linux/percpu.h>
  
  #ifdef CONFIG_QUICKLIST
  
  struct quicklist {
  	void *page;
  	int nr_pages;
  };
  
  DECLARE_PER_CPU(struct quicklist, quicklist)[CONFIG_NR_QUICK];
  
  /*
   * The two key functions quicklist_alloc and quicklist_free are inline so
   * that they may be custom compiled for the platform.
   * Specifying a NULL ctor can remove constructor support. Specifying
   * a constant quicklist allows the determination of the exact address
   * in the per cpu area.
   *
   * The fast patch in quicklist_alloc touched only a per cpu cacheline and
   * the first cacheline of the page itself. There is minmal overhead involved.
   */
  static inline void *quicklist_alloc(int nr, gfp_t flags, void (*ctor)(void *))
  {
  	struct quicklist *q;
  	void **p = NULL;
  
  	q =&get_cpu_var(quicklist)[nr];
  	p = q->page;
  	if (likely(p)) {
  		q->page = p[0];
  		p[0] = NULL;
  		q->nr_pages--;
  	}
  	put_cpu_var(quicklist);
  	if (likely(p))
  		return p;
  
  	p = (void *)__get_free_page(flags | __GFP_ZERO);
  	if (ctor && p)
  		ctor(p);
  	return p;
  }
  
  static inline void __quicklist_free(int nr, void (*dtor)(void *), void *p,
  	struct page *page)
  {
  	struct quicklist *q;
6225e9373   Christoph Lameter   Quicklists for pa... 
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  	q = &get_cpu_var(quicklist)[nr];
  	*(void **)p = q->page;
  	q->page = p;
  	q->nr_pages++;
  	put_cpu_var(quicklist);
  }
  
  static inline void quicklist_free(int nr, void (*dtor)(void *), void *pp)
  {
  	__quicklist_free(nr, dtor, pp, virt_to_page(pp));
  }
  
  static inline void quicklist_free_page(int nr, void (*dtor)(void *),
  							struct page *page)
  {
  	__quicklist_free(nr, dtor, page_address(page), page);
  }
  
  void quicklist_trim(int nr, void (*dtor)(void *),
  	unsigned long min_pages, unsigned long max_free);
  
  unsigned long quicklist_total_size(void);
4b8561521   KOSAKI Motohiro   mm: show quicklis... 
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  #else
  
  static inline unsigned long quicklist_total_size(void)
  {
  	return 0;
  }
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  #endif
  
  #endif /* LINUX_QUICKLIST_H */