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/module.h>
21 #include <linux/quicklist.h>
23 DEFINE_PER_CPU(struct quicklist
[CONFIG_NR_QUICK
], quicklist
);
25 #define FRACTION_OF_NODE_MEM 16
27 static unsigned long max_pages(unsigned long min_pages
)
29 unsigned long node_free_pages
, max
;
30 int node
= numa_node_id();
31 struct zone
*zones
= NODE_DATA(node
)->node_zones
;
35 #ifdef CONFIG_ZONE_DMA
36 zone_page_state(&zones
[ZONE_DMA
], NR_FREE_PAGES
) +
38 #ifdef CONFIG_ZONE_DMA32
39 zone_page_state(&zones
[ZONE_DMA32
], NR_FREE_PAGES
) +
41 zone_page_state(&zones
[ZONE_NORMAL
], NR_FREE_PAGES
);
43 max
= node_free_pages
/ FRACTION_OF_NODE_MEM
;
45 num_cpus_on_node
= cpumask_weight(cpumask_of_node(node
));
46 max
/= num_cpus_on_node
;
48 return max(max
, min_pages
);
51 static long min_pages_to_free(struct quicklist
*q
,
52 unsigned long min_pages
, long max_free
)
56 pages_to_free
= q
->nr_pages
- max_pages(min_pages
);
58 return min(pages_to_free
, max_free
);
62 * Trim down the number of pages in the quicklist
64 void quicklist_trim(int nr
, void (*dtor
)(void *),
65 unsigned long min_pages
, unsigned long max_free
)
70 q
= &get_cpu_var(quicklist
)[nr
];
71 if (q
->nr_pages
> min_pages
) {
72 pages_to_free
= min_pages_to_free(q
, min_pages
, max_free
);
74 while (pages_to_free
> 0) {
76 * We pass a gfp_t of 0 to quicklist_alloc here
77 * because we will never call into the page allocator.
79 void *p
= quicklist_alloc(nr
, 0, NULL
);
83 free_page((unsigned long)p
);
87 put_cpu_var(quicklist
);
90 unsigned long quicklist_total_size(void)
92 unsigned long count
= 0;
94 struct quicklist
*ql
, *q
;
96 for_each_online_cpu(cpu
) {
97 ql
= per_cpu(quicklist
, cpu
);
98 for (q
= ql
; q
< ql
+ CONFIG_NR_QUICK
; q
++)
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