remove Z option and default to something halfway to J.

we always junk small chunks now, and the first part of pages,
but only after free. J still does the old thing. j disables everything.
Consider experimental as we evaluate performance in the real world.
ok otto

1 files changed, 22 insertions, 32 deletions

diff --git a/src/lib/libc/stdlib/malloc.c b/src/lib/libc/stdlib/malloc.c
index 6c38d6ad87..e7a113c8cd 100644
--- a/src/lib/libc/stdlib/malloc.c
+++ b/src/lib/libc/stdlib/malloc.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: malloc.c,v 1.157 2014/04/23 10:47:15 espie Exp $      */
+/*      $OpenBSD: malloc.c,v 1.158 2014/04/23 15:07:27 tedu Exp $       */
 /*
  * Copyright (c) 2008, 2010, 2011 Otto Moerbeek <otto@drijf.net>
  * Copyright (c) 2012 Matthew Dempsky <matthew@openbsd.org>
@@ -167,7 +167,6 @@ struct malloc_readonly {
         int     malloc_move;            /* move allocations to end of page? */
         int     malloc_realloc;         /* always realloc? */
         int     malloc_xmalloc;         /* xmalloc behaviour? */
-        int     malloc_zero;            /* zero fill? */
         size_t  malloc_guard;           /* use guard pages after allocations? */
         u_int   malloc_cache;           /* free pages we cache */
 #ifdef MALLOC_STATS
@@ -414,7 +413,7 @@ map(struct dir_info *d, size_t sz, int zero_fill)
                                 d->free_regions_size -= psz;
                                 if (zero_fill)
                                         memset(p, 0, sz);
-                                else if (mopts.malloc_junk &&
+                                else if (mopts.malloc_junk == 2 &&
                                     mopts.malloc_freeunmap)
                                         memset(p, SOME_FREEJUNK, sz);
                                 return p;
@@ -433,7 +432,7 @@ map(struct dir_info *d, size_t sz, int zero_fill)
                 d->free_regions_size -= psz;
                 if (zero_fill)
                         memset(p, 0, sz);
-                else if (mopts.malloc_junk && mopts.malloc_freeunmap)
+                else if (mopts.malloc_junk == 2 && mopts.malloc_freeunmap)
                         memset(p, SOME_FREEJUNK, sz);
                 return p;
         }
@@ -463,6 +462,7 @@ omalloc_init(struct dir_info **dp)
          * Default options
          */
         mopts.malloc_abort = 1;
+        mopts.malloc_junk = 1;
         mopts.malloc_move = 1;
         mopts.malloc_cache = MALLOC_DEFAULT_CACHE;
 
@@ -536,7 +536,7 @@ omalloc_init(struct dir_info **dp)
                                 mopts.malloc_junk = 0;
                                 break;
                         case 'J':
-                                mopts.malloc_junk = 1;
+                                mopts.malloc_junk = 2;
                                 break;
                         case 'n':
                         case 'N':
@@ -559,7 +559,8 @@ omalloc_init(struct dir_info **dp)
                                 mopts.malloc_cache = MALLOC_DEFAULT_CACHE;
                                 break;
                         case 'S':
-                                mopts.malloc_freeunmap = mopts.malloc_junk = 1;
+                                mopts.malloc_freeunmap = 1;
+                                mopts.malloc_junk = 2;
                                 mopts.malloc_guard = MALLOC_PAGESIZE;
                                 mopts.malloc_cache = 0;
                                 break;
@@ -575,12 +576,6 @@ omalloc_init(struct dir_info **dp)
                         case 'X':
                                 mopts.malloc_xmalloc = 1;
                                 break;
-                        case 'z':
-                                mopts.malloc_zero = 0;
-                                break;
-                        case 'Z':
-                                mopts.malloc_zero = 1;
-                                break;
                         default: {
                                 static const char q[] = "malloc() warning: "
                                     "unknown char in MALLOC_OPTIONS\n";
@@ -591,13 +586,6 @@ omalloc_init(struct dir_info **dp)
                 }
         }
 
-        /*
-         * We want junk in the entire allocation, and zero only in the part
-         * the user asked for.
-         */
-        if (mopts.malloc_zero)
-                mopts.malloc_junk = 1;
-
 #ifdef MALLOC_STATS
         if (mopts.malloc_stats && (atexit(malloc_exit) == -1)) {
                 static const char q[] = "malloc() warning: atexit(2) failed."
@@ -971,7 +959,7 @@ malloc_bytes(struct dir_info *d, size_t size, void *f)
         k += (lp - bp->bits) * MALLOC_BITS;
         k <<= bp->shift;
 
-        if (mopts.malloc_junk && bp->size > 0)
+        if (mopts.malloc_junk == 2 && bp->size > 0)
                 memset((char *)bp->page + k, SOME_JUNK, bp->size);
         return ((char *)bp->page + k);
 }
@@ -1069,16 +1057,16 @@ omalloc(size_t sz, int zero_fill, void *f)
                     sz - mopts.malloc_guard < MALLOC_PAGESIZE -
                     MALLOC_LEEWAY) {
                         /* fill whole allocation */
-                        if (mopts.malloc_junk)
+                        if (mopts.malloc_junk == 2)
                                 memset(p, SOME_JUNK, psz - mopts.malloc_guard);
                         /* shift towards the end */
                         p = ((char *)p) + ((MALLOC_PAGESIZE - MALLOC_LEEWAY -
                             (sz - mopts.malloc_guard)) & ~(MALLOC_MINSIZE-1));
                         /* fill zeros if needed and overwritten above */
-                        if (zero_fill && mopts.malloc_junk)
+                        if (zero_fill && mopts.malloc_junk == 2)
                                 memset(p, 0, sz - mopts.malloc_guard);
                 } else {
-                        if (mopts.malloc_junk) {
+                        if (mopts.malloc_junk == 2) {
                                 if (zero_fill)
                                         memset((char *)p + sz - mopts.malloc_guard,
                                             SOME_JUNK, psz - sz);
@@ -1146,7 +1134,7 @@ malloc(size_t size)
                 malloc_recurse();
                 return NULL;
         }
-        r = omalloc(size, mopts.malloc_zero, CALLER);
+        r = omalloc(size, 0, CALLER);
         malloc_active--;
         _MALLOC_UNLOCK();
         if (r == NULL && mopts.malloc_xmalloc) {
@@ -1198,9 +1186,11 @@ ofree(void *p)
                         }
                         malloc_guarded -= mopts.malloc_guard;
                 }
-                if (mopts.malloc_junk && !mopts.malloc_freeunmap)
-                        memset(p, SOME_FREEJUNK,
-                            PAGEROUND(sz) - mopts.malloc_guard);
+                if (mopts.malloc_junk && !mopts.malloc_freeunmap) {
+                        size_t amt = mopts.malloc_junk == 1 ? MALLOC_MAXCHUNK :
+                            PAGEROUND(sz) - mopts.malloc_guard;
+                        memset(p, SOME_FREEJUNK, amt);
+                }
                 unmap(g_pool, p, PAGEROUND(sz));
                 delete(g_pool, r);
         } else {
@@ -1304,7 +1294,7 @@ orealloc(void *p, size_t newsz, void *f)
                                         q = MAP_FAILED;
                                 if (q == hint) {
                                         malloc_used += needed;
-                                        if (mopts.malloc_junk)
+                                        if (mopts.malloc_junk == 2)
                                                 memset(q, SOME_JUNK, needed);
                                         r->size = newsz;
                                         STATS_SETF(r, f);
@@ -1331,7 +1321,7 @@ orealloc(void *p, size_t newsz, void *f)
                         STATS_SETF(r, f);
                         return p;
                 } else {
-                        if (newsz > oldsz && mopts.malloc_junk)
+                        if (newsz > oldsz && mopts.malloc_junk == 2)
                                 memset((char *)p + newsz, SOME_JUNK,
                                     rnewsz - mopts.malloc_guard - newsz);
                         r->size = gnewsz;
@@ -1340,7 +1330,7 @@ orealloc(void *p, size_t newsz, void *f)
                 }
         }
         if (newsz <= oldsz && newsz > oldsz / 2 && !mopts.malloc_realloc) {
-                if (mopts.malloc_junk && newsz > 0)
+                if (mopts.malloc_junk == 2 && newsz > 0)
                         memset((char *)p + newsz, SOME_JUNK, oldsz - newsz);
                 STATS_SETF(r, f);
                 return p;
@@ -1525,7 +1515,7 @@ omemalign(size_t alignment, size_t sz, int zero_fill, void *f)
                 malloc_guarded += mopts.malloc_guard;
         }
 
-        if (mopts.malloc_junk) {
+        if (mopts.malloc_junk == 2) {
                 if (zero_fill)
                         memset((char *)p + sz - mopts.malloc_guard,
                             SOME_JUNK, psz - sz);
@@ -1556,7 +1546,7 @@ posix_memalign(void **memptr, size_t alignment, size_t size)
                 malloc_recurse();
                 goto err;
         }
-        r = omemalign(alignment, size, mopts.malloc_zero, CALLER);
+        r = omemalign(alignment, size, 0, CALLER);
         malloc_active--;
         _MALLOC_UNLOCK();
         if (r == NULL) {