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