lib/interval_tree_test.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 #include <linux/module.h>
   3 #include <linux/moduleparam.h>
   4 #include <linux/interval_tree.h>
   5 #include <linux/random.h>
   6 #include <linux/slab.h>
   7 #include <asm/timex.h>
   8
   9 #define __param(type, name, init, msg)          \
  10         static type name = init;                \
  11         module_param(name, type, 0444);         \
  12         MODULE_PARM_DESC(name, msg);
  13
  14 __param(int, nnodes, 100, "Number of nodes in the interval tree");
  15 __param(int, perf_loops, 1000, "Number of iterations modifying the tree");
  16
  17 __param(int, nsearches, 100, "Number of searches to the interval tree");
  18 __param(int, search_loops, 1000, "Number of iterations searching the tree");
  19 __param(bool, search_all, false, "Searches will iterate all nodes in the tree");
  20
  21 __param(uint, max_endpoint, ~0, "Largest value for the interval's endpoint");
  22
  23 static struct rb_root_cached root = RB_ROOT_CACHED;
  24 static struct interval_tree_node *nodes = NULL;
  25 static u32 *queries = NULL;
  26
  27 static struct rnd_state rnd;
  28
  29 static inline unsigned long
  30 search(struct rb_root_cached *root, unsigned long start, unsigned long last)
  31 {
  32         struct interval_tree_node *node;
  33         unsigned long results = 0;
  34
  35         for (node = interval_tree_iter_first(root, start, last); node;
  36              node = interval_tree_iter_next(node, start, last))
  37                 results++;
  38         return results;
  39 }
  40
  41 static void init(void)
  42 {
  43         int i;
  44
  45         for (i = 0; i < nnodes; i++) {
  46                 u32 b = (prandom_u32_state(&rnd) >> 4) % max_endpoint;
  47                 u32 a = (prandom_u32_state(&rnd) >> 4) % b;
  48
  49                 nodes[i].start = a;
  50                 nodes[i].last = b;
  51         }
  52
  53         /*
  54          * Limit the search scope to what the user defined.
  55          * Otherwise we are merely measuring empty walks,
  56          * which is pointless.
  57          */
  58         for (i = 0; i < nsearches; i++)
  59                 queries[i] = (prandom_u32_state(&rnd) >> 4) % max_endpoint;
  60 }
  61
  62 static int interval_tree_test_init(void)
  63 {
  64         int i, j;
  65         unsigned long results;
  66         cycles_t time1, time2, time;
  67
  68         nodes = kmalloc_array(nnodes, sizeof(struct interval_tree_node),
  69                               GFP_KERNEL);
  70         if (!nodes)
  71                 return -ENOMEM;
  72
  73         queries = kmalloc_array(nsearches, sizeof(int), GFP_KERNEL);
  74         if (!queries) {
  75                 kfree(nodes);
  76                 return -ENOMEM;
  77         }
  78
  79         printk(KERN_ALERT "interval tree insert/remove");
  80
  81         prandom_seed_state(&rnd, 3141592653589793238ULL);
  82         init();
  83
  84         time1 = get_cycles();
  85
  86         for (i = 0; i < perf_loops; i++) {
  87                 for (j = 0; j < nnodes; j++)
  88                         interval_tree_insert(nodes + j, &root);
  89                 for (j = 0; j < nnodes; j++)
  90                         interval_tree_remove(nodes + j, &root);
  91         }
  92
  93         time2 = get_cycles();
  94         time = time2 - time1;
  95
  96         time = div_u64(time, perf_loops);
  97         printk(" -> %llu cycles\n", (unsigned long long)time);
  98
  99         printk(KERN_ALERT "interval tree search");
 100
 101         for (j = 0; j < nnodes; j++)
 102                 interval_tree_insert(nodes + j, &root);
 103
 104         time1 = get_cycles();
 105
 106         results = 0;
 107         for (i = 0; i < search_loops; i++)
 108                 for (j = 0; j < nsearches; j++) {
 109                         unsigned long start = search_all ? 0 : queries[j];
 110                         unsigned long last = search_all ? max_endpoint : queries[j];
 111
 112                         results += search(&root, start, last);
 113                 }
 114
 115         time2 = get_cycles();
 116         time = time2 - time1;
 117
 118         time = div_u64(time, search_loops);
 119         results = div_u64(results, search_loops);
 120         printk(" -> %llu cycles (%lu results)\n",
 121                (unsigned long long)time, results);
 122
 123         kfree(queries);
 124         kfree(nodes);
 125
 126         return -EAGAIN; /* Fail will directly unload the module */
 127 }
 128
 129 static void interval_tree_test_exit(void)
 130 {
 131         printk(KERN_ALERT "test exit\n");
 132 }
 133
 134 module_init(interval_tree_test_init)
 135 module_exit(interval_tree_test_exit)
 136
 137 MODULE_LICENSE("GPL");
 138 MODULE_AUTHOR("Michel Lespinasse");
 139 MODULE_DESCRIPTION("Interval Tree test");