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
10 * Copyright (C) 2007 SGI,
11 * Christoph Lameter <clameter@sgi.com>
12 * Generalized, added support for multiple lists and
13 * constructors / destructors.
15 #include <linux/kernel.h>
17 #include <linux/gfp.h>
19 #include <linux/mmzone.h>
20 #include <linux/quicklist.h>
22 DEFINE_PER_CPU(struct quicklist
[CONFIG_NR_QUICK
], quicklist
);
24 #define FRACTION_OF_NODE_MEM 16
26 static unsigned long max_pages(unsigned long min_pages
)
28 unsigned long node_free_pages
, max
;
29 int node
= numa_node_id();
30 struct zone
*zones
= NODE_DATA(node
)->node_zones
;
34 #ifdef CONFIG_ZONE_DMA
35 zone_page_state(&zones
[ZONE_DMA
], NR_FREE_PAGES
) +
37 #ifdef CONFIG_ZONE_DMA32
38 zone_page_state(&zones
[ZONE_DMA32
], NR_FREE_PAGES
) +
40 zone_page_state(&zones
[ZONE_NORMAL
], NR_FREE_PAGES
);
42 max
= node_free_pages
/ FRACTION_OF_NODE_MEM
;
44 num_cpus_on_node
= cpumask_weight(cpumask_of_node(node
));
45 max
/= num_cpus_on_node
;
47 return max(max
, min_pages
);
50 static long min_pages_to_free(struct quicklist
*q
,
51 unsigned long min_pages
, long max_free
)
55 pages_to_free
= q
->nr_pages
- max_pages(min_pages
);
57 return min(pages_to_free
, max_free
);
61 * Trim down the number of pages in the quicklist
63 void quicklist_trim(int nr
, void (*dtor
)(void *),
64 unsigned long min_pages
, unsigned long max_free
)
69 q
= &get_cpu_var(quicklist
)[nr
];
70 if (q
->nr_pages
> min_pages
) {
71 pages_to_free
= min_pages_to_free(q
, min_pages
, max_free
);
73 while (pages_to_free
> 0) {
75 * We pass a gfp_t of 0 to quicklist_alloc here
76 * because we will never call into the page allocator.
78 void *p
= quicklist_alloc(nr
, 0, NULL
);
82 free_page((unsigned long)p
);
86 put_cpu_var(quicklist
);
89 unsigned long quicklist_total_size(void)
91 unsigned long count
= 0;
93 struct quicklist
*ql
, *q
;
95 for_each_online_cpu(cpu
) {
96 ql
= per_cpu(quicklist
, cpu
);
97 for (q
= ql
; q
< ql
+ CONFIG_NR_QUICK
; q
++)