496f2f93b1
This renames all random32 functions to have 'prandom_' prefix as follows: void prandom_seed(u32 seed); /* rename from srandom32() */ u32 prandom_u32(void); /* rename from random32() */ void prandom_seed_state(struct rnd_state *state, u64 seed); /* rename from prandom32_seed() */ u32 prandom_u32_state(struct rnd_state *state); /* rename from prandom32() */ The purpose of this renaming is to prevent some kernel developers from assuming that prandom32() and random32() might imply that only prandom32() was the one using a pseudo-random number generator by prandom32's "p", and the result may be a very embarassing security exposure. This concern was expressed by Theodore Ts'o. And furthermore, I'm going to introduce new functions for getting the requested number of pseudo-random bytes. If I continue to use both prandom32 and random32 prefixes for these functions, the confusion is getting worse. As a result of this renaming, "prandom_" is the common prefix for pseudo-random number library. Currently, srandom32() and random32() are preserved because it is difficult to rename too many users at once. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Robert Love <robert.w.love@intel.com> Cc: Michel Lespinasse <walken@google.com> Cc: Valdis Kletnieks <valdis.kletnieks@vt.edu> Cc: David Laight <david.laight@aculab.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Artem Bityutskiy <dedekind1@gmail.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Eilon Greenstein <eilong@broadcom.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
107 lines
2.3 KiB
C
107 lines
2.3 KiB
C
#include <linux/module.h>
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#include <linux/interval_tree.h>
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#include <linux/random.h>
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#include <asm/timex.h>
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#define NODES 100
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#define PERF_LOOPS 100000
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#define SEARCHES 100
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#define SEARCH_LOOPS 10000
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static struct rb_root root = RB_ROOT;
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static struct interval_tree_node nodes[NODES];
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static u32 queries[SEARCHES];
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static struct rnd_state rnd;
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static inline unsigned long
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search(unsigned long query, struct rb_root *root)
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{
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struct interval_tree_node *node;
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unsigned long results = 0;
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for (node = interval_tree_iter_first(root, query, query); node;
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node = interval_tree_iter_next(node, query, query))
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results++;
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return results;
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}
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static void init(void)
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{
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int i;
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for (i = 0; i < NODES; i++) {
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u32 a = prandom_u32_state(&rnd);
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u32 b = prandom_u32_state(&rnd);
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if (a <= b) {
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nodes[i].start = a;
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nodes[i].last = b;
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} else {
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nodes[i].start = b;
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nodes[i].last = a;
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}
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}
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for (i = 0; i < SEARCHES; i++)
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queries[i] = prandom_u32_state(&rnd);
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}
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static int interval_tree_test_init(void)
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{
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int i, j;
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unsigned long results;
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cycles_t time1, time2, time;
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printk(KERN_ALERT "interval tree insert/remove");
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prandom_seed_state(&rnd, 3141592653589793238ULL);
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init();
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time1 = get_cycles();
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for (i = 0; i < PERF_LOOPS; i++) {
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for (j = 0; j < NODES; j++)
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interval_tree_insert(nodes + j, &root);
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for (j = 0; j < NODES; j++)
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interval_tree_remove(nodes + j, &root);
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}
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time2 = get_cycles();
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time = time2 - time1;
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time = div_u64(time, PERF_LOOPS);
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printk(" -> %llu cycles\n", (unsigned long long)time);
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printk(KERN_ALERT "interval tree search");
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for (j = 0; j < NODES; j++)
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interval_tree_insert(nodes + j, &root);
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time1 = get_cycles();
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results = 0;
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for (i = 0; i < SEARCH_LOOPS; i++)
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for (j = 0; j < SEARCHES; j++)
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results += search(queries[j], &root);
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time2 = get_cycles();
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time = time2 - time1;
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time = div_u64(time, SEARCH_LOOPS);
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results = div_u64(results, SEARCH_LOOPS);
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printk(" -> %llu cycles (%lu results)\n",
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(unsigned long long)time, results);
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return -EAGAIN; /* Fail will directly unload the module */
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}
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static void interval_tree_test_exit(void)
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{
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printk(KERN_ALERT "test exit\n");
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}
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module_init(interval_tree_test_init)
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module_exit(interval_tree_test_exit)
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Michel Lespinasse");
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MODULE_DESCRIPTION("Interval Tree test");
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