src/patches/glibc/glibc-rh740506.patch

   1 2011-11-14  Andreas Schwab  <schwab@redhat.com>
   2
   3         * malloc/arena.c (arena_get2): Don't call reused_arena when
   4         _int_new_arena failed.
   5
   6 2011-11-10  Andreas Schwab  <schwab@redhat.com>
   7
   8         * malloc/arena.c (_int_new_arena): Don't increment narenas.
   9         (reused_arena): Don't check arena limit.
  10         (arena_get2): Atomically check arena limit.
  11
  12 diff --git a/malloc/arena.c b/malloc/arena.c
  13 index 9114fd2..042cac8 100644
  14 --- a/malloc/arena.c
  15 +++ b/malloc/arena.c
  16 @@ -747,8 +747,6 @@ _int_new_arena(size_t size)
  17    main_arena.next = a;
  18
  19  #ifdef PER_THREAD
  20 -  ++narenas;
  21 -
  22    (void)mutex_unlock(&list_lock);
  23  #endif
  24
  25 @@ -786,30 +784,6 @@ get_free_list (void)
  26  static mstate
  27  reused_arena (void)
  28  {
  29 -  if (narenas <= mp_.arena_test)
  30 -    return NULL;
  31 -
  32 -  static int narenas_limit;
  33 -  if (narenas_limit == 0)
  34 -    {
  35 -      if (mp_.arena_max != 0)
  36 -       narenas_limit = mp_.arena_max;
  37 -      else
  38 -       {
  39 -         int n  = __get_nprocs ();
  40 -
  41 -         if (n >= 1)
  42 -           narenas_limit = NARENAS_FROM_NCORES (n);
  43 -         else
  44 -           /* We have no information about the system.  Assume two
  45 -              cores.  */
  46 -           narenas_limit = NARENAS_FROM_NCORES (2);
  47 -       }
  48 -    }
  49 -
  50 -  if (narenas < narenas_limit)
  51 -    return NULL;
  52 -
  53    mstate result;
  54    static mstate next_to_use;
  55    if (next_to_use == NULL)
  56 @@ -844,10 +818,41 @@ arena_get2(mstate a_tsd, size_t size)
  57    mstate a;
  58
  59  #ifdef PER_THREAD
  60 -  if ((a = get_free_list ()) == NULL
  61 -      && (a = reused_arena ()) == NULL)
  62 -    /* Nothing immediately available, so generate a new arena.  */
  63 -    a = _int_new_arena(size);
  64 +  static size_t narenas_limit;
  65 +
  66 +  a = get_free_list ();
  67 +  if (a == NULL)
  68 +    {
  69 +      /* Nothing immediately available, so generate a new arena.  */
  70 +      if (narenas_limit == 0)
  71 +       {
  72 +         if (mp_.arena_max != 0)
  73 +           narenas_limit = mp_.arena_max;
  74 +         else
  75 +           {
  76 +             int n  = __get_nprocs ();
  77 +
  78 +             if (n >= 1)
  79 +               narenas_limit = NARENAS_FROM_NCORES (n);
  80 +             else
  81 +               /* We have no information about the system.  Assume two
  82 +                  cores.  */
  83 +               narenas_limit = NARENAS_FROM_NCORES (2);
  84 +           }
  85 +       }
  86 +    repeat:;
  87 +      size_t n = narenas;
  88 +      if (__builtin_expect (n <= mp_.arena_test || n < narenas_limit, 0))
  89 +       {
  90 +         if (catomic_compare_and_exchange_bool_acq(&narenas, n + 1, n))
  91 +           goto repeat;
  92 +         a = _int_new_arena (size);
  93 +         if (__builtin_expect (a != NULL, 1))
  94 +           return a;
  95 +         catomic_decrement(&narenas);
  96 +       }
  97 +      a = reused_arena ();
  98 +    }
  99  #else
 100    if(!a_tsd)
 101      a = a_tsd = &main_arena;
 102
 103 commit a5fb313cb7b7e692fd4684916aaa98e03ec7e8b6
 104 Author: Andreas Schwab <schwab@redhat.com>
 105 Date:   Mon Nov 14 11:41:52 2011 +0100
 106
 107     Don't call reused_arena when _int_new_arena failed
 108
 109 diff --git a/malloc/arena.c b/malloc/arena.c
 110 index 042cac8..cb8548b 100644
 111 --- a/malloc/arena.c
 112 +++ b/malloc/arena.c
 113 @@ -844,14 +844,14 @@ arena_get2(mstate a_tsd, size_t size)
 114        size_t n = narenas;
 115        if (__builtin_expect (n <= mp_.arena_test || n < narenas_limit, 0))
 116         {
 117 -         if (catomic_compare_and_exchange_bool_acq(&narenas, n + 1, n))
 118 +         if (catomic_compare_and_exchange_bool_acq (&narenas, n + 1, n))
 119             goto repeat;
 120           a = _int_new_arena (size);
 121 -         if (__builtin_expect (a != NULL, 1))
 122 -           return a;
 123 -         catomic_decrement(&narenas);
 124 +         if (__builtin_expect (a == NULL, 0))
 125 +           catomic_decrement (&narenas);
 126         }
 127 -      a = reused_arena ();
 128 +      else
 129 +       a = reused_arena ();
 130      }
 131  #else
 132    if(!a_tsd)