src/patches/suse-2.6.27.25/patches.xen/xen-swiotlb-heuristics

   1 From: jbeulich@novell.com
   2 Subject: adjust Xen's swiotlb default size setting
   3 Patch-mainline: obsolete
   4
   5 --- sle11-2009-02-05.orig/lib/swiotlb-xen.c     2009-02-05 11:18:17.000000000 +0100
   6 +++ sle11-2009-02-05/lib/swiotlb-xen.c  2009-02-05 11:18:23.000000000 +0100
   7 @@ -224,8 +224,8 @@ swiotlb_init_with_default_size(size_t de
   8  void __init
   9  swiotlb_init(void)
  10  {
  11 -       long ram_end;
  12 -       size_t defsz = 64 * (1 << 20); /* 64MB default size */
  13 +       unsigned long ram_end;
  14 +       size_t defsz = 64 << 20; /* 64MB default size */
  15
  16         if (swiotlb_force == 1) {
  17                 swiotlb = 1;
  18 @@ -234,8 +234,12 @@ swiotlb_init(void)
  19                    is_initial_xendomain()) {
  20                 /* Domain 0 always has a swiotlb. */
  21                 ram_end = HYPERVISOR_memory_op(XENMEM_maximum_ram_page, NULL);
  22 -               if (ram_end <= 0x7ffff)
  23 -                       defsz = 2 * (1 << 20); /* 2MB on <2GB on systems. */
  24 +               if (ram_end <= 0x1ffff)
  25 +                       defsz = 2 << 20; /* 2MB on <512MB systems. */
  26 +               else if (ram_end <= 0x3ffff)
  27 +                       defsz = 4 << 20; /* 4MB on <1GB systems. */
  28 +               else if (ram_end <= 0x7ffff)
  29 +                       defsz = 8 << 20; /* 8MB on <2GB systems. */
  30                 swiotlb = 1;
  31         }
  32