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

diff --git a/lib/libc/stdlib/malloc.c b/lib/libc/stdlib/malloc.c
index 6c38d6a..e7a113c 100644 (file)
--- a/lib/libc/stdlib/malloc.c
+++ b/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) {