projects / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 6225e937 CL |
1 | /* |
| 2 | * Quicklist support. | |
| 3 | * | |
| 4 | * Quicklists are light weight lists of pages that have a defined state | |
| 5 | * on alloc and free. Pages must be in the quicklist specific defined state | |
| 6 | * (zero by default) when the page is freed. It seems that the initial idea | |
| 7 | * for such lists first came from Dave Miller and then various other people | |
| 8 | * improved on it. | |
| 9 | * | |
| 10 | * Copyright (C) 2007 SGI, | |
| 11 | * Christoph Lameter <[email protected]> | |
| 12 | * Generalized, added support for multiple lists and | |
| 13 | * constructors / destructors. | |
| 14 | */ | |
| 15 | #include <linux/kernel.h> | |
| 16 | ||
| 17 | #include <linux/mm.h> | |
| 18 | #include <linux/mmzone.h> | |
| 19 | #include <linux/module.h> | |
| 20 | #include <linux/quicklist.h> | |
| 21 | ||
| 22 | DEFINE_PER_CPU(struct quicklist, quicklist)[CONFIG_NR_QUICK]; | |
| 23 | ||
| 24 | #define FRACTION_OF_NODE_MEM 16 | |
| 25 | ||
| 26 | static unsigned long max_pages(unsigned long min_pages) | |
| 27 | { | |
| 28 | unsigned long node_free_pages, max; | |
| 96990a4a CL |
29 | struct zone *zones = NODE_DATA(numa_node_id())->node_zones; |
| 30 | ||
| 31 | node_free_pages = | |
| 32 | #ifdef CONFIG_ZONE_DMA | |
| 33 | zone_page_state(&zones[ZONE_DMA], NR_FREE_PAGES) + | |
| 34 | #endif | |
| 35 | #ifdef CONFIG_ZONE_DMA32 | |
| 36 | zone_page_state(&zones[ZONE_DMA32], NR_FREE_PAGES) + | |
| 37 | #endif | |
| 38 | zone_page_state(&zones[ZONE_NORMAL], NR_FREE_PAGES); | |
| 6225e937 | 39 | |
| 6225e937 CL |
40 | max = node_free_pages / FRACTION_OF_NODE_MEM; |
| 41 | return max(max, min_pages); | |
| 42 | } | |
| 43 | ||
| 44 | static long min_pages_to_free(struct quicklist *q, | |
| 45 | unsigned long min_pages, long max_free) | |
| 46 | { | |
| 47 | long pages_to_free; | |
| 48 | ||
| 49 | pages_to_free = q->nr_pages - max_pages(min_pages); | |
| 50 | ||
| 51 | return min(pages_to_free, max_free); | |
| 52 | } | |
| 53 | ||
| 54 | /* | |
| 55 | * Trim down the number of pages in the quicklist | |
| 56 | */ | |
| 57 | void quicklist_trim(int nr, void (*dtor)(void *), | |
| 58 | unsigned long min_pages, unsigned long max_free) | |
| 59 | { | |
| 60 | long pages_to_free; | |
| 61 | struct quicklist *q; | |
| 62 | ||
| 63 | q = &get_cpu_var(quicklist)[nr]; | |
| 64 | if (q->nr_pages > min_pages) { | |
| 65 | pages_to_free = min_pages_to_free(q, min_pages, max_free); | |
| 66 | ||
| 67 | while (pages_to_free > 0) { | |
| 68 | /* | |
| 69 | * We pass a gfp_t of 0 to quicklist_alloc here | |
| 70 | * because we will never call into the page allocator. | |
| 71 | */ | |
| 72 | void *p = quicklist_alloc(nr, 0, NULL); | |
| 73 | ||
| 74 | if (dtor) | |
| 75 | dtor(p); | |
| 76 | free_page((unsigned long)p); | |
| 77 | pages_to_free--; | |
| 78 | } | |
| 79 | } | |
| 80 | put_cpu_var(quicklist); | |
| 81 | } | |
| 82 | ||
| 83 | unsigned long quicklist_total_size(void) | |
| 84 | { | |
| 85 | unsigned long count = 0; | |
| 86 | int cpu; | |
| 87 | struct quicklist *ql, *q; | |
| 88 | ||
| 89 | for_each_online_cpu(cpu) { | |
| 90 | ql = per_cpu(quicklist, cpu); | |
| 91 | for (q = ql; q < ql + CONFIG_NR_QUICK; q++) | |
| 92 | count += q->nr_pages; | |
| 93 | } | |
| 94 | return count; | |
| 95 | } | |
| 96 |