Single Zone Optimizations If we only have a single zone then various macros can be optimized. We do not need to protect higher zones etc etc. Signed-off-by: Christoph Lameter Index: linux-2.6.18-rc1-mm1/mm/vmstat.c =================================================================== --- linux-2.6.18-rc1-mm1.orig/mm/vmstat.c 2006-07-10 11:11:32.493846183 -0700 +++ linux-2.6.18-rc1-mm1/mm/vmstat.c 2006-07-10 11:14:02.209204861 -0700 @@ -499,7 +499,7 @@ static int zoneinfo_show(struct seq_file for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) seq_printf(m, "\n %-12s %lu", vmstat_text[i], zone_page_state(zone, i)); - +#ifndef SINGLE_ZONE seq_printf(m, "\n protection: (%lu", zone->lowmem_reserve[0]); @@ -508,6 +508,7 @@ static int zoneinfo_show(struct seq_file seq_printf(m, ")" "\n pagesets"); +#endif for_each_online_cpu(i) { struct per_cpu_pageset *pageset; int j; Index: linux-2.6.18-rc1-mm1/mm/page_alloc.c =================================================================== --- linux-2.6.18-rc1-mm1.orig/mm/page_alloc.c 2006-07-10 11:11:50.129475277 -0700 +++ linux-2.6.18-rc1-mm1/mm/page_alloc.c 2006-07-10 11:14:02.211157865 -0700 @@ -57,6 +57,7 @@ int percpu_pagelist_fraction; static void __free_pages_ok(struct page *page, unsigned int order); +#ifndef SINGLE_ZONE /* * results with 256, 32 in the lowmem_reserve sysctl: * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high) @@ -79,6 +80,7 @@ int sysctl_lowmem_reserve_ratio[MAX_NR_Z 32 #endif }; +#endif EXPORT_SYMBOL(totalram_pages); @@ -884,8 +886,11 @@ int zone_watermark_ok(struct zone *z, in min -= min / 2; if (alloc_flags & ALLOC_HARDER) min -= min / 4; - +#ifdef SINGLE_ZONE + if (free_pages <= min) +#else if (free_pages <= min + z->lowmem_reserve[classzone_idx]) +#endif return 0; for (o = 0; o < order; o++) { /* At the next order, this order's pages become unavailable */ @@ -1422,10 +1427,12 @@ void show_free_areas(void) zone->pages_scanned, (zone->all_unreclaimable ? "yes" : "no") ); +#ifndef SINGLE_ZONE printk("lowmem_reserve[]:"); for (i = 0; i < MAX_NR_ZONES; i++) printk(" %lu", zone->lowmem_reserve[i]); printk("\n"); +#endif } for_each_zone(zone) { @@ -2247,12 +2254,13 @@ static void calculate_totalreserve_pages struct zone *zone = pgdat->node_zones + i; unsigned long max = 0; +#ifndef SINGLE_ZONE /* Find valid and maximum lowmem_reserve in the zone */ for (j = i; j < MAX_NR_ZONES; j++) { if (zone->lowmem_reserve[j] > max) max = zone->lowmem_reserve[j]; } - +#endif /* we treat pages_high as reserved pages. */ max += zone->pages_high; @@ -2272,6 +2280,7 @@ static void calculate_totalreserve_pages */ static void setup_per_zone_lowmem_reserve(void) { +#ifndef SINGLE_ZONE struct pglist_data *pgdat; int j, idx; @@ -2298,6 +2307,7 @@ static void setup_per_zone_lowmem_reserv /* update totalreserve_pages */ calculate_totalreserve_pages(); +#endif } /* @@ -2431,6 +2441,7 @@ int sysctl_min_unmapped_ratio_sysctl_han } #endif +#ifndef SINGLE_ZONE /* * lowmem_reserve_ratio_sysctl_handler - just a wrapper around * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve() @@ -2447,6 +2458,7 @@ int lowmem_reserve_ratio_sysctl_handler( setup_per_zone_lowmem_reserve(); return 0; } +#endif /* * percpu_pagelist_fraction - changes the pcp->high for each zone on each Index: linux-2.6.18-rc1-mm1/kernel/sysctl.c =================================================================== --- linux-2.6.18-rc1-mm1.orig/kernel/sysctl.c 2006-07-10 10:33:44.314897008 -0700 +++ linux-2.6.18-rc1-mm1/kernel/sysctl.c 2006-07-10 11:14:02.213110870 -0700 @@ -903,6 +903,7 @@ static ctl_table vm_table[] = { .proc_handler = &proc_dointvec, }, #endif +#ifndef SINGLE_ZONE { .ctl_name = VM_LOWMEM_RESERVE_RATIO, .procname = "lowmem_reserve_ratio", @@ -912,6 +913,7 @@ static ctl_table vm_table[] = { .proc_handler = &lowmem_reserve_ratio_sysctl_handler, .strategy = &sysctl_intvec, }, +#endif { .ctl_name = VM_DROP_PAGECACHE, .procname = "drop_caches", Index: linux-2.6.18-rc1-mm1/include/linux/mmzone.h =================================================================== --- linux-2.6.18-rc1-mm1.orig/include/linux/mmzone.h 2006-07-10 11:13:41.428262351 -0700 +++ linux-2.6.18-rc1-mm1/include/linux/mmzone.h 2006-07-10 11:14:26.596369844 -0700 @@ -196,6 +196,7 @@ enum zone_type { #define GFP_ZONEMASK 0x00 #define ZONES_SHIFT 0 #define GFP_ZONETYPES 1 +#define SINGLE_ZONE 1 #endif #endif @@ -205,6 +206,7 @@ struct zone { /* Fields commonly accessed by the page allocator */ unsigned long free_pages; unsigned long pages_min, pages_low, pages_high; +#ifndef SINGLE_ZONE /* * We don't know if the memory that we're going to allocate will be freeable * or/and it will be released eventually, so to avoid totally wasting several @@ -214,6 +216,7 @@ struct zone { * sysctl_lowmem_reserve_ratio sysctl changes. */ unsigned long lowmem_reserve[MAX_NR_ZONES]; +#endif #ifdef CONFIG_NUMA /* @@ -436,7 +439,11 @@ unsigned long __init node_memmap_size_by /* * zone_idx() returns 0 for the ZONE_DMA zone, 1 for the ZONE_NORMAL zone, etc. */ +#ifndef SINGLE_ZONE #define zone_idx(zone) ((zone) - (zone)->zone_pgdat->node_zones) +#else +#define zone_idx(zone) ZONE_NORMAL +#endif static inline int populated_zone(struct zone *zone) { @@ -454,7 +461,11 @@ static inline int is_highmem_idx(enum zo static inline int is_normal_idx(enum zone_type idx) { +#ifndef SINGLE_ZONE return (idx == ZONE_NORMAL); +#else + return 1; +#endif } /** @@ -474,7 +485,9 @@ static inline int is_highmem(struct zone static inline int is_normal(struct zone *zone) { +#ifndef SINGLE_ZONE return zone == zone->zone_pgdat->node_zones + ZONE_NORMAL; +#endif } static inline int is_dma32(struct zone *zone) @@ -500,9 +513,11 @@ struct ctl_table; struct file; int min_free_kbytes_sysctl_handler(struct ctl_table *, int, struct file *, void __user *, size_t *, loff_t *); +#ifndef SINGLE_ZONE extern int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1]; int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *, int, struct file *, void __user *, size_t *, loff_t *); +#endif int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *, int, struct file *, void __user *, size_t *, loff_t *); int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *, int,