/* SPDX-License-Identifier: GPL-2.0 */ #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 <cl@linux.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; 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); #else static inline unsigned long quicklist_total_size(void) { return 0; } #endif #endif /* LINUX_QUICKLIST_H */