git.maemo.org Git - kernel-bfs/blob - kernel-bfs-2.6.28/debian/patches/mm-lots_watermark.diff

   1 The vm currently performs scanning when allocating ram once the watermarks
   2 are below the pages_low value and tries to restore them to the pages_high
   3 watermark. The disadvantage of this is that we are scanning most aggresssively
   4 at the same time we are allocating ram regardless of the stress the vm is
   5 under. Add a pages_lots watermark and allow the watermark to be relaxed
   6 according to the stress the vm is at the time (according to the priority
   7 value). Thus we have more in reserve next time we are allocating ram and end
   8 up scanning less aggresssively. Note the actual pages_lots isn't used directly
   9 in this code.
  10
  11 Signed-off-by: Con Kolivas <kernel@kolivas.org>
  12
  13  include/linux/mmzone.h |    2 +-
  14  mm/page_alloc.c        |    3 +++
  15  mm/vmscan.c            |   17 ++++++++++++++---
  16  3 files changed, 18 insertions(+), 4 deletions(-)
  17
  18 Index: linux-2.6.22-ck1/include/linux/mmzone.h
  19 ===================================================================
  20 --- linux-2.6.22-ck1.orig/include/linux/mmzone.h        2007-07-09 18:44:34.000000000 +1000
  21 +++ linux-2.6.22-ck1/include/linux/mmzone.h     2007-07-09 18:44:39.000000000 +1000
  22 @@ -181,7 +181,7 @@ enum zone_type {
  23
  24  struct zone {
  25         /* Fields commonly accessed by the page allocator */
  26 -       unsigned long           pages_min, pages_low, pages_high;
  27 +       unsigned long           pages_min, pages_low, pages_high, pages_lots;
  28         /*
  29          * We don't know if the memory that we're going to allocate will be freeable
  30          * or/and it will be released eventually, so to avoid totally wasting several
  31 Index: linux-2.6.22-ck1/mm/page_alloc.c
  32 ===================================================================
  33 --- linux-2.6.22-ck1.orig/mm/page_alloc.c       2007-07-09 18:44:34.000000000 +1000
  34 +++ linux-2.6.22-ck1/mm/page_alloc.c    2007-07-09 18:44:39.000000000 +1000
  35 @@ -1570,6 +1570,7 @@ void show_free_areas(void)
  36                         " min:%lukB"
  37                         " low:%lukB"
  38                         " high:%lukB"
  39 +                       " lots:%lukB"
  40                         " active_anon:%lukB"
  41                         " inactive_anon:%lukB"
  42                         " active_file:%lukB"
  43 @@ -1581,6 +1582,7 @@ void show_free_areas(void)
  44                         K(zone->pages_min),
  45                         K(zone->pages_low),
  46                         K(zone->pages_high),
  47 +                       K(zone->pages_lots),
  48                         K(zone_page_state(zone, NR_ACTIVE_ANON)),
  49                         K(zone_page_state(zone, NR_INACTIVE_ANON)),
  50                         K(zone_page_state(zone, NR_ACTIVE_FILE)),
  51 @@ -3142,6 +3144,7 @@ void setup_per_zone_pages_min(void)
  52
  53                 zone->pages_low   = zone->pages_min + (tmp >> 2);
  54                 zone->pages_high  = zone->pages_min + (tmp >> 1);
  55 +               zone->pages_lots  = zone->pages_min + tmp;
  56                 setup_zone_migrate_reserve(zone);
  57                 spin_unlock_irqrestore(&zone->lock, flags);
  58         }
  59 Index: linux-2.6.22-ck1/mm/vmscan.c
  60 ===================================================================
  61 --- linux-2.6.22-ck1.orig/mm/vmscan.c   2007-07-09 18:44:39.000000000 +1000
  62 +++ linux-2.6.22-ck1/mm/vmscan.c        2007-07-09 18:44:39.000000000 +1000
  63 @@ -1171,6 +1171,7 @@ loop_again:
  64                  */
  65                 for (i = pgdat->nr_zones - 1; i >= 0; i--) {
  66                         struct zone *zone = pgdat->node_zones + i;
  67 +                       unsigned long watermark;
  68
  69                         if (!populated_zone(zone))
  70                                 continue;
  71 @@ -1178,8 +1179,14 @@ loop_again:
  72                                 shrink_active_list(SWAP_CLUSTER_MAX, zone,
  73                                                         &sc, priority, 0);
  74
  75 -                       if (!zone_watermark_ok(zone, order, zone->pages_high,
  76 -                                              0, 0)) {
  77 +                       /*
  78 +                        * The watermark is relaxed depending on the
  79 +                        * level of "priority" till it drops to
  80 +                        * pages_high.
  81 +                        */
  82 +                       watermark = zone->pages_high + (zone->pages_high *
  83 +                                   priority / DEF_PRIORITY);
  84 +                       if (!zone_watermark_ok(zone, order, watermark, 0, 0)) {
  85                                 end_zone = i;
  86                                 break;
  87                         }
  88 @@ -1206,6 +1213,7 @@ loop_again:
  89                 for (i = 0; i <= end_zone; i++) {
  90                         struct zone *zone = pgdat->node_zones + i;
  91                         int nr_slab;
  92 +                       unsigned long watermark;
  93
  94                         if (!populated_zone(zone))
  95                                 continue;
  96 @@ -1213,7 +1221,10 @@ loop_again:
  97                                         priority != DEF_PRIORITY)
  98                                 continue;
  99
 100 -                       if (!zone_watermark_ok(zone, order, zone->pages_high,
 101 +                       watermark = zone->pages_high + (zone->pages_high *
 102 +                                   priority / DEF_PRIORITY);
 103 +
 104 +                       if (!zone_watermark_ok(zone, order, watermark,
 105                                                end_zone, 0))
 106                                 all_zones_ok = 0;
 107                         temp_priority[i] = priority;
 108