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>
18 #include <linux/mmzone.h>
19 #include <linux/module.h>
20 #include <linux/quicklist.h>
22 DEFINE_PER_CPU(struct quicklist
, quicklist
)[CONFIG_NR_QUICK
];
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 struct zone
*zones
= NODE_DATA(numa_node_id())->node_zones
;
32 #ifdef CONFIG_ZONE_DMA
33 zone_page_state(&zones
[ZONE_DMA
], NR_FREE_PAGES
) +
35 #ifdef CONFIG_ZONE_DMA32
36 zone_page_state(&zones
[ZONE_DMA32
], NR_FREE_PAGES
) +
38 zone_page_state(&zones
[ZONE_NORMAL
], NR_FREE_PAGES
);
40 max
= node_free_pages
/ FRACTION_OF_NODE_MEM
;
41 return max(max
, min_pages
);
44 static long min_pages_to_free(struct quicklist
*q
,
45 unsigned long min_pages
, long max_free
)
49 pages_to_free
= q
->nr_pages
- max_pages(min_pages
);
51 return min(pages_to_free
, max_free
);
55 * Trim down the number of pages in the quicklist
57 void quicklist_trim(int nr
, void (*dtor
)(void *),
58 unsigned long min_pages
, unsigned long max_free
)
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
);
67 while (pages_to_free
> 0) {
69 * We pass a gfp_t of 0 to quicklist_alloc here
70 * because we will never call into the page allocator.
72 void *p
= quicklist_alloc(nr
, 0, NULL
);
76 free_page((unsigned long)p
);
80 put_cpu_var(quicklist
);
83 unsigned long quicklist_total_size(void)
85 unsigned long count
= 0;
87 struct quicklist
*ql
, *q
;
89 for_each_online_cpu(cpu
) {
90 ql
= per_cpu(quicklist
, cpu
);
91 for (q
= ql
; q
< ql
+ CONFIG_NR_QUICK
; q
++)
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