lib/interval_tree_test.c

   1 #include <linux/module.h>
   2 #include <linux/moduleparam.h>
   3 #include <linux/interval_tree.h>
   4 #include <linux/random.h>
   5 #include <linux/slab.h>
   6 #include <asm/timex.h>
   7
   8 #define __param(type, name, init, msg)          \
   9         static type name = init;                \
  10         module_param(name, type, 0444);         \
  11         MODULE_PARM_DESC(name, msg);
  12
  13 __param(int, nnodes, 100, "Number of nodes in the interval tree");
  14 __param(int, perf_loops, 1000, "Number of iterations modifying the tree");
  15
  16 __param(int, nsearches, 100, "Number of searches to the interval tree");
  17 __param(int, search_loops, 1000, "Number of iterations searching the tree");
  18 __param(bool, search_all, false, "Searches will iterate all nodes in the tree");
  19
  20 __param(uint, max_endpoint, ~0, "Largest value for the interval's endpoint");
  21
  22 static struct rb_root_cached root = RB_ROOT_CACHED;
  23 static struct interval_tree_node *nodes = NULL;
  24 static u32 *queries = NULL;
  25
  26 static struct rnd_state rnd;
  27
  28 static inline unsigned long
  29 search(struct rb_root_cached *root, unsigned long start, unsigned long last)
  30 {
  31         struct interval_tree_node *node;
  32         unsigned long results = 0;
  33
  34         for (node = interval_tree_iter_first(root, start, last); node;
  35              node = interval_tree_iter_next(node, start, last))
  36                 results++;
  37         return results;
  38 }
  39
  40 static void init(void)
  41 {
  42         int i;
  43
  44         for (i = 0; i < nnodes; i++) {
  45                 u32 b = (prandom_u32_state(&rnd) >> 4) % max_endpoint;
  46                 u32 a = (prandom_u32_state(&rnd) >> 4) % b;
  47
  48                 nodes[i].start = a;
  49                 nodes[i].last = b;
  50         }
  51
  52         /*
  53          * Limit the search scope to what the user defined.
  54          * Otherwise we are merely measuring empty walks,
  55          * which is pointless.
  56          */
  57         for (i = 0; i < nsearches; i++)
  58                 queries[i] = (prandom_u32_state(&rnd) >> 4) % max_endpoint;
  59 }
  60
  61 static int interval_tree_test_init(void)
  62 {
  63         int i, j;
  64         unsigned long results;
  65         cycles_t time1, time2, time;
  66
  67         nodes = kmalloc_array(nnodes, sizeof(struct interval_tree_node),
  68                               GFP_KERNEL);
  69         if (!nodes)
  70                 return -ENOMEM;
  71
  72         queries = kmalloc_array(nsearches, sizeof(int), GFP_KERNEL);
  73         if (!queries) {
  74                 kfree(nodes);
  75                 return -ENOMEM;
  76         }
  77
  78         printk(KERN_ALERT "interval tree insert/remove");
  79
  80         prandom_seed_state(&rnd, 3141592653589793238ULL);
  81         init();
  82
  83         time1 = get_cycles();
  84
  85         for (i = 0; i < perf_loops; i++) {
  86                 for (j = 0; j < nnodes; j++)
  87                         interval_tree_insert(nodes + j, &root);
  88                 for (j = 0; j < nnodes; j++)
  89                         interval_tree_remove(nodes + j, &root);
  90         }
  91
  92         time2 = get_cycles();
  93         time = time2 - time1;
  94
  95         time = div_u64(time, perf_loops);
  96         printk(" -> %llu cycles\n", (unsigned long long)time);
  97
  98         printk(KERN_ALERT "interval tree search");
  99
 100         for (j = 0; j < nnodes; j++)
 101                 interval_tree_insert(nodes + j, &root);
 102
 103         time1 = get_cycles();
 104
 105         results = 0;
 106         for (i = 0; i < search_loops; i++)
 107                 for (j = 0; j < nsearches; j++) {
 108                         unsigned long start = search_all ? 0 : queries[j];
 109                         unsigned long last = search_all ? max_endpoint : queries[j];
 110
 111                         results += search(&root, start, last);
 112                 }
 113
 114         time2 = get_cycles();
 115         time = time2 - time1;
 116
 117         time = div_u64(time, search_loops);
 118         results = div_u64(results, search_loops);
 119         printk(" -> %llu cycles (%lu results)\n",
 120                (unsigned long long)time, results);
 121
 122         kfree(queries);
 123         kfree(nodes);
 124
 125         return -EAGAIN; /* Fail will directly unload the module */
 126 }
 127
 128 static void interval_tree_test_exit(void)
 129 {
 130         printk(KERN_ALERT "test exit\n");
 131 }
 132
 133 module_init(interval_tree_test_init)
 134 module_exit(interval_tree_test_exit)
 135
 136 MODULE_LICENSE("GPL");
 137 MODULE_AUTHOR("Michel Lespinasse");
 138 MODULE_DESCRIPTION("Interval Tree test");