diff options
Diffstat (limited to 'kernel/mm/quicklist.c')
-rw-r--r-- | kernel/mm/quicklist.c | 102 |
1 files changed, 102 insertions, 0 deletions
diff --git a/kernel/mm/quicklist.c b/kernel/mm/quicklist.c new file mode 100644 index 000000000..942212970 --- /dev/null +++ b/kernel/mm/quicklist.c @@ -0,0 +1,102 @@ +/* + * Quicklist support. + * + * Quicklists are light weight lists of pages that have a defined state + * on alloc and free. Pages must be in the quicklist specific defined state + * (zero by default) when the page is freed. It seems that the initial idea + * for such lists first came from Dave Miller and then various other people + * improved on it. + * + * Copyright (C) 2007 SGI, + * Christoph Lameter <clameter@sgi.com> + * Generalized, added support for multiple lists and + * constructors / destructors. + */ +#include <linux/kernel.h> + +#include <linux/gfp.h> +#include <linux/mm.h> +#include <linux/mmzone.h> +#include <linux/quicklist.h> + +DEFINE_PER_CPU(struct quicklist [CONFIG_NR_QUICK], quicklist); + +#define FRACTION_OF_NODE_MEM 16 + +static unsigned long max_pages(unsigned long min_pages) +{ + unsigned long node_free_pages, max; + int node = numa_node_id(); + struct zone *zones = NODE_DATA(node)->node_zones; + int num_cpus_on_node; + + node_free_pages = +#ifdef CONFIG_ZONE_DMA + zone_page_state(&zones[ZONE_DMA], NR_FREE_PAGES) + +#endif +#ifdef CONFIG_ZONE_DMA32 + zone_page_state(&zones[ZONE_DMA32], NR_FREE_PAGES) + +#endif + zone_page_state(&zones[ZONE_NORMAL], NR_FREE_PAGES); + + max = node_free_pages / FRACTION_OF_NODE_MEM; + + num_cpus_on_node = cpumask_weight(cpumask_of_node(node)); + max /= num_cpus_on_node; + + return max(max, min_pages); +} + +static long min_pages_to_free(struct quicklist *q, + unsigned long min_pages, long max_free) +{ + long pages_to_free; + + pages_to_free = q->nr_pages - max_pages(min_pages); + + return min(pages_to_free, max_free); +} + +/* + * Trim down the number of pages in the quicklist + */ +void quicklist_trim(int nr, void (*dtor)(void *), + unsigned long min_pages, unsigned long max_free) +{ + long pages_to_free; + struct quicklist *q; + + q = &get_cpu_var(quicklist)[nr]; + if (q->nr_pages > min_pages) { + pages_to_free = min_pages_to_free(q, min_pages, max_free); + + while (pages_to_free > 0) { + /* + * We pass a gfp_t of 0 to quicklist_alloc here + * because we will never call into the page allocator. + */ + void *p = quicklist_alloc(nr, 0, NULL); + + if (dtor) + dtor(p); + free_page((unsigned long)p); + pages_to_free--; + } + } + put_cpu_var(quicklist); +} + +unsigned long quicklist_total_size(void) +{ + unsigned long count = 0; + int cpu; + struct quicklist *ql, *q; + + for_each_online_cpu(cpu) { + ql = per_cpu(quicklist, cpu); + for (q = ql; q < ql + CONFIG_NR_QUICK; q++) + count += q->nr_pages; + } + return count; +} + |