If you do 'echo 0 0 > /proc/sys/vm/lowmem_reserve_ratio' the kernel gets a
divide-by-zero.

Prevent that, and fiddle with some whitespace too.

Signed-off-by: Andrew Morton <[EMAIL PROTECTED]>
---

 25-akpm/mm/page_alloc.c |   21 +++++++++++++++------
 1 files changed, 15 insertions(+), 6 deletions(-)

diff -puN mm/page_alloc.c~setup_per_zone_lowmem_reserve-oops-fix mm/page_alloc.c
--- 25/mm/page_alloc.c~setup_per_zone_lowmem_reserve-oops-fix   2005-03-04 
13:16:10.000000000 -0800
+++ 25-akpm/mm/page_alloc.c     2005-03-04 13:16:10.000000000 -0800
@@ -37,13 +37,17 @@
 #include <asm/tlbflush.h>
 #include "internal.h"
 
-/* MCD - HACK: Find somewhere to initialize this EARLY, or make this 
initializer cleaner */
+/*
+ * MCD - HACK: Find somewhere to initialize this EARLY, or make this
+ * initializer cleaner
+ */
 nodemask_t node_online_map = { { [0] = 1UL } };
 nodemask_t node_possible_map = NODE_MASK_ALL;
 struct pglist_data *pgdat_list;
 unsigned long totalram_pages;
 unsigned long totalhigh_pages;
 long nr_swap_pages;
+
 /*
  * results with 256, 32 in the lowmem_reserve sysctl:
  *     1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
@@ -1924,15 +1928,20 @@ static void setup_per_zone_lowmem_reserv
 
        for_each_pgdat(pgdat) {
                for (j = 0; j < MAX_NR_ZONES; j++) {
-                       struct zone * zone = pgdat->node_zones + j;
+                       struct zone *zone = pgdat->node_zones + j;
                        unsigned long present_pages = zone->present_pages;
 
                        zone->lowmem_reserve[j] = 0;
 
                        for (idx = j-1; idx >= 0; idx--) {
-                               struct zone * lower_zone = pgdat->node_zones + 
idx;
+                               struct zone *lower_zone;
+
+                               if (sysctl_lowmem_reserve_ratio[idx] < 1)
+                                       sysctl_lowmem_reserve_ratio[idx] = 1;
 
-                               lower_zone->lowmem_reserve[j] = present_pages / 
sysctl_lowmem_reserve_ratio[idx];
+                               lower_zone = pgdat->node_zones + idx;
+                               lower_zone->lowmem_reserve[j] = present_pages /
+                                       sysctl_lowmem_reserve_ratio[idx];
                                present_pages += lower_zone->present_pages;
                        }
                }
@@ -2039,7 +2048,7 @@ module_init(init_per_zone_pages_min)
  *     changes.
  */
 int min_free_kbytes_sysctl_handler(ctl_table *table, int write, 
-               struct file *file, void __user *buffer, size_t *length, loff_t 
*ppos)
+       struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
 {
        proc_dointvec(table, write, file, buffer, length, ppos);
        setup_per_zone_pages_min();
@@ -2056,7 +2065,7 @@ int min_free_kbytes_sysctl_handler(ctl_t
  * if in function of the boot time zone sizes.
  */
 int lowmem_reserve_ratio_sysctl_handler(ctl_table *table, int write,
-                struct file *file, void __user *buffer, size_t *length, loff_t 
*ppos)
+       struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
 {
        proc_dointvec_minmax(table, write, file, buffer, length, ppos);
        setup_per_zone_lowmem_reserve();
_
-
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