Remove --enable-tunables configure option

And make always supported.  The configure option was added on glibc 2.25
and some features require it (such as hwcap mask, huge pages support, and
lock elisition tuning).  It also simplifies the build permutations.

Changes from v1:
 * Remove glibc.rtld.dynamic_sort changes, it is orthogonal and needs
   more discussion.
 * Cleanup more code.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>

1 files changed, 2 insertions, 116 deletions

diff --git a/malloc/arena.c b/malloc/arena.c
index ccd193953b..e98b779dbb 100644
--- a/malloc/arena.c
+++ b/malloc/arena.c
@@ -18,9 +18,7 @@
 
 #include <stdbool.h>
 
-#if HAVE_TUNABLES
-# define TUNABLE_NAMESPACE malloc
-#endif
+#define TUNABLE_NAMESPACE malloc
 #include <elf/dl-tunables.h>
 
 /* Compile-time constants.  */
@@ -47,21 +45,13 @@
 static inline size_t
 heap_min_size (void)
 {
-#if HAVE_TUNABLES
   return mp_.hp_pagesize == 0 ? HEAP_MIN_SIZE : mp_.hp_pagesize;
-#else
-  return HEAP_MIN_SIZE;
-#endif
 }
 
 static inline size_t
 heap_max_size (void)
 {
-#if HAVE_TUNABLES
   return mp_.hp_pagesize == 0 ? HEAP_MAX_SIZE : mp_.hp_pagesize * 4;
-#else
-  return HEAP_MAX_SIZE;
-#endif
 }
 
 /***************************************************************************/
@@ -239,8 +229,7 @@ __malloc_fork_unlock_child (void)
   __libc_lock_init (list_lock);
 }
 
-#if HAVE_TUNABLES
-# define TUNABLE_CALLBACK_FNDECL(__name, __type) \
+#define TUNABLE_CALLBACK_FNDECL(__name, __type) \
 static inline int do_ ## __name (__type value);				      \
 static void									      \
 TUNABLE_CALLBACK (__name) (tunable_val_t *valp)				      \
@@ -263,42 +252,6 @@ TUNABLE_CALLBACK_FNDECL (set_tcache_unsorted_limit, size_t)
 #endif
 TUNABLE_CALLBACK_FNDECL (set_mxfast, size_t)
 TUNABLE_CALLBACK_FNDECL (set_hugetlb, size_t)
-#else
-/* Initialization routine. */
-#include <string.h>
-extern char **_environ;
-
-static char *
-next_env_entry (char ***position)
-{
-  char **current = *position;
-  char *result = NULL;
-
-  while (*current != NULL)
-    {
-      if (__builtin_expect ((*current)[0] == 'M', 0)
-          && (*current)[1] == 'A'
-          && (*current)[2] == 'L'
-          && (*current)[3] == 'L'
-          && (*current)[4] == 'O'
-          && (*current)[5] == 'C'
-          && (*current)[6] == '_')
-        {
-          result = &(*current)[7];
-
-          /* Save current position for next visit.  */
-          *position = ++current;
-
-          break;
-        }
-
-      ++current;
-    }
-
-  return result;
-}
-#endif
-
 
 #if USE_TCACHE
 static void tcache_key_initialize (void);
@@ -343,7 +296,6 @@ ptmalloc_init (void)
 
   malloc_init_state (&main_arena);
 
-#if HAVE_TUNABLES
   TUNABLE_GET (top_pad, size_t, TUNABLE_CALLBACK (set_top_pad));
   TUNABLE_GET (perturb, int32_t, TUNABLE_CALLBACK (set_perturb_byte));
   TUNABLE_GET (mmap_threshold, size_t, TUNABLE_CALLBACK (set_mmap_threshold));
@@ -363,70 +315,6 @@ ptmalloc_init (void)
     /* Force mmap for main arena instead of sbrk, so hugepages are explicitly
        used.  */
     __always_fail_morecore = true;
-#else
-  if (__glibc_likely (_environ != NULL))
-    {
-      char **runp = _environ;
-      char *envline;
-
-      while (__builtin_expect ((envline = next_env_entry (&runp)) != NULL,
-                               0))
-        {
-          size_t len = strcspn (envline, "=");
-
-          if (envline[len] != '=')
-            /* This is a "MALLOC_" variable at the end of the string
-               without a '=' character.  Ignore it since otherwise we
-               will access invalid memory below.  */
-            continue;
-
-          switch (len)
-            {
-            case 8:
-              if (!__builtin_expect (__libc_enable_secure, 0))
-                {
-                  if (memcmp (envline, "TOP_PAD_", 8) == 0)
-                    __libc_mallopt (M_TOP_PAD, strtol (&envline[9], NULL, 10));
-                  else if (memcmp (envline, "PERTURB_", 8) == 0)
-                    __libc_mallopt (M_PERTURB, strtol (&envline[9], NULL, 10));
-                }
-              break;
-            case 9:
-              if (!__builtin_expect (__libc_enable_secure, 0))
-                {
-                  if (memcmp (envline, "MMAP_MAX_", 9) == 0)
-                    __libc_mallopt (M_MMAP_MAX, strtol (&envline[10],
-							NULL, 10));
-                  else if (memcmp (envline, "ARENA_MAX", 9) == 0)
-                    __libc_mallopt (M_ARENA_MAX, strtol (&envline[10],
-							 NULL, 10));
-                }
-              break;
-            case 10:
-              if (!__builtin_expect (__libc_enable_secure, 0))
-                {
-                  if (memcmp (envline, "ARENA_TEST", 10) == 0)
-                    __libc_mallopt (M_ARENA_TEST, strtol (&envline[11],
-							  NULL, 10));
-                }
-              break;
-            case 15:
-              if (!__builtin_expect (__libc_enable_secure, 0))
-                {
-                  if (memcmp (envline, "TRIM_THRESHOLD_", 15) == 0)
-                    __libc_mallopt (M_TRIM_THRESHOLD, strtol (&envline[16],
-							      NULL, 10));
-                  else if (memcmp (envline, "MMAP_THRESHOLD_", 15) == 0)
-                    __libc_mallopt (M_MMAP_THRESHOLD, strtol (&envline[16],
-							      NULL, 10));
-                }
-              break;
-            default:
-              break;
-            }
-        }
-    }
-#endif
 }
 
 /* Managing heaps and arenas (for concurrent threads) */
@@ -561,7 +449,6 @@ alloc_new_heap  (size_t size, size_t top_pad, size_t pagesize,
 static heap_info *
 new_heap (size_t size, size_t top_pad)
 {
-#if HAVE_TUNABLES
   if (__glibc_unlikely (mp_.hp_pagesize != 0))
     {
       heap_info *h = alloc_new_heap (size, top_pad, mp_.hp_pagesize,
@@ -569,7 +456,6 @@ new_heap (size_t size, size_t top_pad)
       if (h != NULL)
 	return h;
     }
-#endif
   return alloc_new_heap (size, top_pad, GLRO (dl_pagesize), 0);
 }