diff --git a/Documentation/sysctl/vm.txt b/Documentation/sysctl/vm.txt index ff234d229cbb..17256f2ad919 100644 --- a/Documentation/sysctl/vm.txt +++ b/Documentation/sysctl/vm.txt @@ -312,8 +312,6 @@ The lowmem_reserve_ratio is an array. You can see them by reading this file. % cat /proc/sys/vm/lowmem_reserve_ratio 256 256 32 - -Note: # of this elements is one fewer than number of zones. Because the highest - zone's value is not necessary for following calculation. But, these values are not used directly. The kernel calculates # of protection pages for each zones from them. These are shown as array of protection pages @@ -364,7 +362,8 @@ As above expression, they are reciprocal number of ratio. pages of higher zones on the node. If you would like to protect more pages, smaller values are effective. -The minimum value is 1 (1/1 -> 100%). +The minimum value is 1 (1/1 -> 100%). The value less than 1 completely +disables protection of the pages. ============================================================== diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index a0c9e45a859a..32699b2dc52a 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -885,7 +885,7 @@ int min_free_kbytes_sysctl_handler(struct ctl_table *, int, void __user *, size_t *, loff_t *); int watermark_scale_factor_sysctl_handler(struct ctl_table *, int, void __user *, size_t *, loff_t *); -extern int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1]; +extern int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES]; int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *, int, void __user *, size_t *, loff_t *); int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *, int, diff --git a/mm/page_alloc.c b/mm/page_alloc.c index b04667848375..34a4c12d2675 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -205,17 +205,18 @@ static void __free_pages_ok(struct page *page, unsigned int order); * TBD: should special case ZONE_DMA32 machines here - in those we normally * don't need any ZONE_NORMAL reservation */ -int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1] = { +int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES] = { #ifdef CONFIG_ZONE_DMA - 256, + [ZONE_DMA] = 256, #endif #ifdef CONFIG_ZONE_DMA32 - 256, + [ZONE_DMA32] = 256, #endif + [ZONE_NORMAL] = 32, #ifdef CONFIG_HIGHMEM - 32, + [ZONE_HIGHMEM] = 0, #endif - 32, + [ZONE_MOVABLE] = 0, }; EXPORT_SYMBOL(totalram_pages); @@ -7132,13 +7133,15 @@ static void setup_per_zone_lowmem_reserve(void) struct zone *lower_zone; idx--; - - if (sysctl_lowmem_reserve_ratio[idx] < 1) - sysctl_lowmem_reserve_ratio[idx] = 1; - lower_zone = pgdat->node_zones + idx; - lower_zone->lowmem_reserve[j] = managed_pages / - sysctl_lowmem_reserve_ratio[idx]; + + if (sysctl_lowmem_reserve_ratio[idx] < 1) { + sysctl_lowmem_reserve_ratio[idx] = 0; + lower_zone->lowmem_reserve[j] = 0; + } else { + lower_zone->lowmem_reserve[j] = + managed_pages / sysctl_lowmem_reserve_ratio[idx]; + } managed_pages += lower_zone->managed_pages; } }