Pages in the malloc cache are either reused quickly or unmapped

quickly. In both cases it does not make sense to set hints on them.
So remove that option, which is just a remainder of old times when
malloc used to hold on to pages. ok stefan@

src/lib/libc/stdlib/malloc.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: malloc.c,v 1.207 2016/10/22 14:27:19 otto Exp $	*/
+/*	$OpenBSD: malloc.c,v 1.208 2016/10/28 17:03:22 otto Exp $	*/
 /*
  * Copyright (c) 2008, 2010, 2011, 2016 Otto Moerbeek <otto@drijf.net>
  * Copyright (c) 2012 Matthew Dempsky <matthew@openbsd.org>
@@ -176,7 +176,6 @@ struct malloc_readonly {
 	int	malloc_mt;		/* multi-threaded mode? */
 	int	malloc_freenow;		/* Free quickly - disable chunk rnd */
 	int	malloc_freeunmap;	/* mprotect free pages PROT_NONE? */
-	int	malloc_hint;		/* call madvice on free pages?  */
 	int	malloc_junk;		/* junk fill? */
 	int	malloc_move;		/* move allocations to end of page? */
 	int	malloc_realloc;		/* always realloc? */
@@ -374,8 +373,6 @@ unmap(struct dir_info *d, void *p, size_t sz)
 				    MALLOC_MAXCHUNK : sz;
 				memset(p, SOME_FREEJUNK, amt);
 			}
-			if (mopts.malloc_hint)
-				madvise(p, sz, MADV_FREE);
 			if (mopts.malloc_freeunmap)
 				mprotect(p, sz, PROT_NONE);
 			r->p = p;
@@ -447,8 +444,6 @@ map(struct dir_info *d, void *hint, size_t sz, int zero_fill)
 				d->free_regions_size -= psz;
 				if (mopts.malloc_freeunmap)
 					mprotect(p, sz, PROT_READ | PROT_WRITE);
-				if (mopts.malloc_hint)
-					madvise(p, sz, MADV_NORMAL);
 				if (zero_fill)
 					memset(p, 0, sz);
 				else if (mopts.malloc_junk == 2 &&
@@ -465,8 +460,6 @@ map(struct dir_info *d, void *hint, size_t sz, int zero_fill)
 		r->p = (char *)r->p + (psz << MALLOC_PAGESHIFT);
 		if (mopts.malloc_freeunmap)
 			mprotect(p, sz, PROT_READ | PROT_WRITE);
-		if (mopts.malloc_hint)
-			madvise(p, sz, MADV_NORMAL);
 		r->size -= psz;
 		d->free_regions_size -= psz;
 		if (zero_fill)
@@ -532,12 +525,6 @@ omalloc_parseopt(char opt)
 	case 'G':
 		mopts.malloc_guard = MALLOC_PAGESIZE;
 		break;
-	case 'h':
-		mopts.malloc_hint = 0;
-		break;
-	case 'H':
-		mopts.malloc_hint = 1;
-		break;
 	case 'j':
 		if (mopts.malloc_junk > 0)
 			mopts.malloc_junk--;