if MALLOC_STATS is defined, record how many "cheap reallocs" were

tried and how many actually succeeded.

1 files changed, 8 insertions, 1 deletions

diff --git a/src/lib/libc/stdlib/malloc.c b/src/lib/libc/stdlib/malloc.c
index 3f3ec951d5..603cc55f18 100644
--- a/src/lib/libc/stdlib/malloc.c
+++ b/src/lib/libc/stdlib/malloc.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: malloc.c,v 1.103 2008/10/20 06:19:02 otto Exp $       */
+/*      $OpenBSD: malloc.c,v 1.104 2008/10/29 14:05:15 otto Exp $       */
 /*
  * Copyright (c) 2008 Otto Moerbeek <otto@drijf.net>
  *
@@ -108,6 +108,8 @@ struct dir_info {
         size_t find_collisions;
         size_t deletes;
         size_t delete_moves;
+        size_t cheap_realloc_tries;
+        size_t cheap_reallocs;
 #define STATS_INC(x) ((x)++)
 #define STATS_ZERO(x) ((x) = 0)
 #else
@@ -271,6 +273,9 @@ malloc_dump1(int fd, struct dir_info *d)
         snprintf(buf, sizeof(buf), "Deletes %zu/%zu\n", d->deletes,
              d->delete_moves);
         write(fd, buf, strlen(buf));
+        snprintf(buf, sizeof(buf), "Cheap reallocs %zu/%zu\n",
+            d->cheap_reallocs, d->cheap_realloc_tries);
+        write(fd, buf, strlen(buf));
         snprintf(buf, sizeof(buf), "Regions slots free %zu\n", d->regions_free);
         write(fd, buf, strlen(buf));
         for (i = 0; i < d->regions_total; i++) {
@@ -1307,6 +1312,7 @@ orealloc(void *p, size_t newsz)
 
                 if (rnewsz > roldsz) {
                         if (!malloc_guard) {
+                                STATS_INC(g_pool.cheap_realloc_tries);
                                 zapcacheregion(&g_pool, p + roldsz);
                                 q = MMAPA(p + roldsz, rnewsz - roldsz);
                                 if (q == p + roldsz) {
@@ -1315,6 +1321,7 @@ orealloc(void *p, size_t newsz)
                                                 memset(q, SOME_JUNK,
                                                     rnewsz - roldsz);
                                         r->size = newsz;
+                                        STATS_INC(g_pool.cheap_reallocs);
                                         return p;
                                 } else if (q != MAP_FAILED)
                                         munmap(q, rnewsz - roldsz);