In 64-bit mode, prefer VM addresses above 1GB.

1 files changed, 12 insertions, 3 deletions

diff --git a/libhurd-mm/as.c b/libhurd-mm/as.c
index b899e46..a966814 100644
--- a/libhurd-mm/as.c
+++ b/libhurd-mm/as.c
@@ -213,9 +213,18 @@ as_alloc (int width, uint64_t count, bool data_mappable)
   vg_addr_t addr = VG_ADDR_VOID;
 
   struct free_space *free_space;
-  for (free_space = hurd_btree_free_space_first (&free_spaces);
-       free_space;
-       free_space = hurd_btree_free_space_next (free_space))
+#if __WORDSIZE == 64
+  /* Prefer virtual addresses above 1 Gb.  */
+  struct region region;
+  region.start = 1024 * 1024 * 1024;
+  region.end = DATA_ADDR_MAX;
+
+  free_space = hurd_btree_free_space_find_first (&free_spaces, &region);
+#else
+  free_space = hurd_btree_free_space_first (&free_spaces);
+#endif
+
+  for (; free_space; free_space = hurd_btree_free_space_next (free_space))
     {
       uint64_t start;
       start = (free_space->region.start + align - 1) & ~(align - 1);