lustre/kernel_patches/patches/vm-tunables-rhel4.patch

   1 Index: linux+rhel4+chaos/mm/page_alloc.c
   2 ===================================================================
   3 --- linux+rhel4+chaos.orig/mm/page_alloc.c
   4 +++ linux+rhel4+chaos/mm/page_alloc.c
   5 @@ -1972,8 +1972,12 @@ static void setup_per_zone_pages_min(voi
   6                                            lowmem_pages;
   7                 }
   8
   9 -               zone->pages_low = zone->pages_min * 2;
  10 -               zone->pages_high = zone->pages_min * 3;
  11 +               /*
  12 +                * When interpreting these watermarks, just keep in mind that:
  13 +                * zone->pages_min == (zone->pages_min * 4) / 4;
  14 +                */
  15 +               zone->pages_low  = (zone->pages_min * 5) / 4;
  16 +               zone->pages_high = (zone->pages_min * 6) / 4;
  17                 spin_unlock_irqrestore(&zone->lru_lock, flags);
  18         }
  19  }
  20 @@ -1982,24 +1986,25 @@ static void setup_per_zone_pages_min(voi
  21   * Initialise min_free_kbytes.
  22   *
  23   * For small machines we want it small (128k min).  For large machines
  24 - * we want it large (16MB max).  But it is not linear, because network
  25 + * we want it large (64MB max).  But it is not linear, because network
  26   * bandwidth does not increase linearly with machine size.  We use
  27   *
  28 - *     min_free_kbytes = sqrt(lowmem_kbytes)
  29 + *     min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy
  30 + *  min_free_kbytes = sqrt(lowmem_kbytes * 16)
  31   *
  32   * which yields
  33   *
  34 - * 16MB:       128k
  35 - * 32MB:       181k
  36 - * 64MB:       256k
  37 - * 128MB:      362k
  38 - * 256MB:      512k
  39 - * 512MB:      724k
  40 - * 1024MB:     1024k
  41 - * 2048MB:     1448k
  42 - * 4096MB:     2048k
  43 - * 8192MB:     2896k
  44 - * 16384MB:    4096k
  45 + * 16MB:       512k
  46 + * 32MB:       724k
  47 + * 64MB:       1024k
  48 + * 128MB:      1448k
  49 + * 256MB:      2048k
  50 + * 512MB:      2896k
  51 + * 1024MB:     4096k
  52 + * 2048MB:     5792k
  53 + * 4096MB:     8192k
  54 + * 8192MB:     11584k
  55 + * 16384MB:    16384k
  56   */
  57  static int __init init_per_zone_pages_min(void)
  58  {
  59 @@ -2007,11 +2012,11 @@ static int __init init_per_zone_pages_mi
  60
  61         lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10);
  62
  63 -       min_free_kbytes = int_sqrt(lowmem_kbytes);
  64 +       min_free_kbytes = int_sqrt(lowmem_kbytes * 16);
  65         if (min_free_kbytes < 128)
  66                 min_free_kbytes = 128;
  67 -       if (min_free_kbytes > 16384)
  68 -               min_free_kbytes = 16384;
  69 +       if (min_free_kbytes > 65536)
  70 +               min_free_kbytes = 65536;
  71         setup_per_zone_pages_min();
  72         setup_per_zone_protection();
  73         return 0;