Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

/*

 *  linux/mm/vmstat.c

 *

 *  Manages VM statistics

 *  Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds

 *

 *  zoned VM statistics

 *  Copyright (C) 2006 Silicon Graphics, Inc.,

 *              Christoph Lameter <christoph@lameter.com>

 */

#include <linux/mm.h>

#include <linux/err.h>

#include <linux/module.h>

#include <linux/cpu.h>

#include <linux/sched.h>

#ifdef CONFIG_VM_EVENT_COUNTERS

DEFINE_PER_CPU(struct vm_event_state, vm_event_states) = {{0}};

EXPORT_PER_CPU_SYMBOL(vm_event_states);

static void sum_vm_events(unsigned long *ret, cpumask_t *cpumask)

{

        int cpu = 0;

        int i;

        memset(ret, 0, NR_VM_EVENT_ITEMS * sizeof(unsigned long));

        cpu = first_cpu(*cpumask);

        while (cpu < NR_CPUS) {

                struct vm_event_state *this = &per_cpu(vm_event_states, cpu);

                cpu = next_cpu(cpu, *cpumask);

                if (cpu < NR_CPUS)

                        prefetch(&per_cpu(vm_event_states, cpu));

                for (i = 0; i < NR_VM_EVENT_ITEMS; i++)

                        ret[i] += this->event[i];

        }

}

/*

 * Accumulate the vm event counters across all CPUs.

 * The result is unavoidably approximate - it can change

 * during and after execution of this function.

*/

void all_vm_events(unsigned long *ret)

{

        sum_vm_events(ret, &cpu_online_map);

}

EXPORT_SYMBOL_GPL(all_vm_events);

#ifdef CONFIG_HOTPLUG

/*

 * Fold the foreign cpu events into our own.

 *

 * This is adding to the events on one processor

 * but keeps the global counts constant.

 */

void vm_events_fold_cpu(int cpu)

{

        struct vm_event_state *fold_state = &per_cpu(vm_event_states, cpu);

        int i;

        for (i = 0; i < NR_VM_EVENT_ITEMS; i++) {

                count_vm_events(i, fold_state->event[i]);

                fold_state->event[i] = 0;

        }

}

#endif /* CONFIG_HOTPLUG */

#endif /* CONFIG_VM_EVENT_COUNTERS */

/*

 * Manage combined zone based / global counters

 *

 * vm_stat contains the global counters

 */

atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS];

EXPORT_SYMBOL(vm_stat);

#ifdef CONFIG_SMP

static int calculate_threshold(struct zone *zone)

{

        int threshold;

        int mem;        /* memory in 128 MB units */

        /*

         * The threshold scales with the number of processors and the amount

         * of memory per zone. More memory means that we can defer updates for

         * longer, more processors could lead to more contention.

         * fls() is used to have a cheap way of logarithmic scaling.

         *

         * Some sample thresholds:

         *

         * Threshold    Processors      (fls)   Zonesize        fls(mem+1)

         * ------------------------------------------------------------------

         * 8            1               1       0.9-1 GB        4

         * 16           2               2       0.9-1 GB        4

         * 20           2               2       1-2 GB          5

         * 24           2               2       2-4 GB          6

         * 28           2               2       4-8 GB          7

         * 32           2               2       8-16 GB         8

         * 4            2               2       <128M           1

         * 30           4               3       2-4 GB          5

         * 48           4               3       8-16 GB         8

         * 32           8               4       1-2 GB          4

         * 32           8               4       0.9-1GB         4

         * 10           16              5       <128M           1

         * 40           16              5       900M            4

         * 70           64              7       2-4 GB          5

         * 84           64              7       4-8 GB          6

         * 108          512             9       4-8 GB          6

         * 125          1024            10      8-16 GB         8

         * 125          1024            10      16-32 GB        9

         */

        mem = zone->present_pages >> (27 - PAGE_SHIFT);

        threshold = 2 * fls(num_online_cpus()) * (1 + fls(mem));

        /*

         * Maximum threshold is 125

         */

        threshold = min(125, threshold);

        return threshold;

}

/*

 * Refresh the thresholds for each zone.

 */

static void refresh_zone_stat_thresholds(void)

{

        struct zone *zone;

        int cpu;

        int threshold;

        for_each_zone(zone) {

                if (!zone->present_pages)

                        continue;

                threshold = calculate_threshold(zone);

                for_each_online_cpu(cpu)

                        zone_pcp(zone, cpu)->stat_threshold = threshold;

        }

}

/*

 * For use when we know that interrupts are disabled.

 */

void __mod_zone_page_state(struct zone *zone, enum zone_stat_item item,

                                int delta)

{

        struct per_cpu_pageset *pcp = zone_pcp(zone, smp_processor_id());

        s8 *p = pcp->vm_stat_diff + item;

        long x;

        x = delta + *p;

        if (unlikely(x > pcp->stat_threshold || x < -pcp->stat_threshold)) {

                zone_page_state_add(x, zone, item);

                x = 0;

        }

        *p = x;

}

EXPORT_SYMBOL(__mod_zone_page_state);

/*

 * For an unknown interrupt state

 */

void mod_zone_page_state(struct zone *zone, enum zone_stat_item item,

                                        int delta)

{

        unsigned long flags;

        local_irq_save(flags);

        __mod_zone_page_state(zone, item, delta);

        local_irq_restore(flags);

}

EXPORT_SYMBOL(mod_zone_page_state);

/*

 * Optimized increment and decrement functions.

 *

 * These are only for a single page and therefore can take a struct page *

 * argument instead of struct zone *. This allows the inclusion of the code

 * generated for page_zone(page) into the optimized functions.

 *

 * No overflow check is necessary and therefore the differential can be

 * incremented or decremented in place which may allow the compilers to

 * generate better code.

 * The increment or decrement is known and therefore one boundary check can

 * be omitted.

 *

 * NOTE: These functions are very performance sensitive. Change only

 * with care.

 *

 * Some processors have inc/dec instructions that are atomic vs an interrupt.

 * However, the code must first determine the differential location in a zone

 * based on the processor number and then inc/dec the counter. There is no

 * guarantee without disabling preemption that the processor will not change

 * in between and therefore the atomicity vs. interrupt cannot be exploited

 * in a useful way here.

 */

void __inc_zone_state(struct zone *zone, enum zone_stat_item item)

{

        struct per_cpu_pageset *pcp = zone_pcp(zone, smp_processor_id());

        s8 *p = pcp->vm_stat_diff + item;

        (*p)++;

        if (unlikely(*p > pcp->stat_threshold)) {

                int overstep = pcp->stat_threshold / 2;

                zone_page_state_add(*p + overstep, zone, item);

                *p = -overstep;

        }

}

void __inc_zone_page_state(struct page *page, enum zone_stat_item item)

{

        __inc_zone_state(page_zone(page), item);

}

EXPORT_SYMBOL(__inc_zone_page_state);

void __dec_zone_state(struct zone *zone, enum zone_stat_item item)

{

        struct per_cpu_pageset *pcp = zone_pcp(zone, smp_processor_id());

        s8 *p = pcp->vm_stat_diff + item;

        (*p)--;

        if (unlikely(*p < - pcp->stat_threshold)) {

                int overstep = pcp->stat_threshold / 2;

                zone_page_state_add(*p - overstep, zone, item);

                *p = overstep;

        }

}

void __dec_zone_page_state(struct page *page, enum zone_stat_item item)

{

        __dec_zone_state(page_zone(page), item);

}

EXPORT_SYMBOL(__dec_zone_page_state);

void inc_zone_state(struct zone *zone, enum zone_stat_item item)

{

        unsigned long flags;

        local_irq_save(flags);

        __inc_zone_state(zone, item);

        local_irq_restore(flags);

}

void inc_zone_page_state(struct page *page, enum zone_stat_item item)

{

        unsigned long flags;

        struct zone *zone;

        zone = page_zone(page);

        local_irq_save(flags);

        __inc_zone_state(zone, item);

        local_irq_restore(flags);

}

EXPORT_SYMBOL(inc_zone_page_state);

void dec_zone_page_state(struct page *page, enum zone_stat_item item)

{

        unsigned long flags;

        local_irq_save(flags);

        __dec_zone_page_state(page, item);

        local_irq_restore(flags);

}

EXPORT_SYMBOL(dec_zone_page_state);

/*

 * Update the zone counters for one cpu.

 *

 * Note that refresh_cpu_vm_stats strives to only access

 * node local memory. The per cpu pagesets on remote zones are placed

 * in the memory local to the processor using that pageset. So the

 * loop over all zones will access a series of cachelines local to

 * the processor.

 *

 * The call to zone_page_state_add updates the cachelines with the

 * statistics in the remote zone struct as well as the global cachelines

 * with the global counters. These could cause remote node cache line

 * bouncing and will have to be only done when necessary.

 */

void refresh_cpu_vm_stats(int cpu)

{

        struct zone *zone;

        int i;

        unsigned long flags;

        for_each_zone(zone) {

                struct per_cpu_pageset *p;

                if (!populated_zone(zone))

                        continue;

                p = zone_pcp(zone, cpu);

                for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)

                        if (p->vm_stat_diff[i]) {

                                local_irq_save(flags);

                                zone_page_state_add(p->vm_stat_diff[i],

                                        zone, i);

                                p->vm_stat_diff[i] = 0;

#ifdef CONFIG_NUMA

                                /* 3 seconds idle till flush */

                                p->expire = 3;

#endif

                                local_irq_restore(flags);

                        }

#ifdef CONFIG_NUMA

                /*

                 * Deal with draining the remote pageset of this

                 * processor

                 *

                 * Check if there are pages remaining in this pageset

                 * if not then there is nothing to expire.

                 */

                if (!p->expire || (!p->pcp[0].count && !p->pcp[1].count))

                        continue;

                /*

                 * We never drain zones local to this processor.

                 */

                if (zone_to_nid(zone) == numa_node_id()) {

                        p->expire = 0;

                        continue;

                }

                p->expire--;

                if (p->expire)

                        continue;

                if (p->pcp[0].count)

                        drain_zone_pages(zone, p->pcp + 0);

                if (p->pcp[1].count)

                        drain_zone_pages(zone, p->pcp + 1);

#endif

        }

}

#endif

#ifdef CONFIG_NUMA

/*

 * zonelist = the list of zones passed to the allocator

 * z        = the zone from which the allocation occurred.

 *

 * Must be called with interrupts disabled.

 */

void zone_statistics(struct zonelist *zonelist, struct zone *z)

{

        if (z->zone_pgdat == zonelist->zones[0]->zone_pgdat) {

                __inc_zone_state(z, NUMA_HIT);

        } else {

                __inc_zone_state(z, NUMA_MISS);

                __inc_zone_state(zonelist->zones[0], NUMA_FOREIGN);

        }

        if (z->node == numa_node_id())

                __inc_zone_state(z, NUMA_LOCAL);

        else

                __inc_zone_state(z, NUMA_OTHER);

}

#endif

#ifdef CONFIG_PROC_FS

#include <linux/seq_file.h>

static char * const migratetype_names[MIGRATE_TYPES] = {

        "Unmovable",

        "Reclaimable",

        "Movable",

        "Reserve",

};

static void *frag_start(struct seq_file *m, loff_t *pos)

{

        pg_data_t *pgdat;

        loff_t node = *pos;

        for (pgdat = first_online_pgdat();

             pgdat && node;

             pgdat = next_online_pgdat(pgdat))

                --node;

        return pgdat;

}

static void *frag_next(struct seq_file *m, void *arg, loff_t *pos)

{

        pg_data_t *pgdat = (pg_data_t *)arg;

        (*pos)++;

        return next_online_pgdat(pgdat);

}

static void frag_stop(struct seq_file *m, void *arg)

{

}

/* Walk all the zones in a node and print using a callback */

static void walk_zones_in_node(struct seq_file *m, pg_data_t *pgdat,

                void (*print)(struct seq_file *m, pg_data_t *, struct zone *))

{

        struct zone *zone;

        struct zone *node_zones = pgdat->node_zones;

        unsigned long flags;

        for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) {

                if (!populated_zone(zone))

                        continue;

                spin_lock_irqsave(&zone->lock, flags);

                print(m, pgdat, zone);

                spin_unlock_irqrestore(&zone->lock, flags);

        }

}

static void frag_show_print(struct seq_file *m, pg_data_t *pgdat,

                                                struct zone *zone)

{

        int order;

        seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);

        for (order = 0; order < MAX_ORDER; ++order)

                seq_printf(m, "%6lu ", zone->free_area[order].nr_free);

        seq_putc(m, '\n');

}

/*

 * This walks the free areas for each zone.

 */

static int frag_show(struct seq_file *m, void *arg)

{

        pg_data_t *pgdat = (pg_data_t *)arg;

        walk_zones_in_node(m, pgdat, frag_show_print);

        return 0;

}

static void pagetypeinfo_showfree_print(struct seq_file *m,

                                        pg_data_t *pgdat, struct zone *zone)

{

        int order, mtype;

        for (mtype = 0; mtype < MIGRATE_TYPES; mtype++) {

                seq_printf(m, "Node %4d, zone %8s, type %12s ",

                                        pgdat->node_id,

                                        zone->name,

                                        migratetype_names[mtype]);

                for (order = 0; order < MAX_ORDER; ++order) {

                        unsigned long freecount = 0;

                        struct free_area *area;

                        struct list_head *curr;

                        area = &(zone->free_area[order]);

                        list_for_each(curr, &area->free_list[mtype])

                                freecount++;

                        seq_printf(m, "%6lu ", freecount);

                }

                seq_putc(m, '\n');

        }

}

/* Print out the free pages at each order for each migatetype */

static int pagetypeinfo_showfree(struct seq_file *m, void *arg)

{

        int order;

        pg_data_t *pgdat = (pg_data_t *)arg;

        /* Print header */

        seq_printf(m, "%-43s ", "Free pages count per migrate type at order");

        for (order = 0; order < MAX_ORDER; ++order)

                seq_printf(m, "%6d ", order);

        seq_putc(m, '\n');

        walk_zones_in_node(m, pgdat, pagetypeinfo_showfree_print);

        return 0;

}

static void pagetypeinfo_showblockcount_print(struct seq_file *m,

                                        pg_data_t *pgdat, struct zone *zone)

{

        int mtype;

        unsigned long pfn;

        unsigned long start_pfn = zone->zone_start_pfn;

        unsigned long end_pfn = start_pfn + zone->spanned_pages;

        unsigned long count[MIGRATE_TYPES] = { 0, };

        for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {

                struct page *page;

                if (!pfn_valid(pfn))

                        continue;

                page = pfn_to_page(pfn);

                mtype = get_pageblock_migratetype(page);

                count[mtype]++;

        }

        /* Print counts */

        seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);

        for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)

                seq_printf(m, "%12lu ", count[mtype]);

        seq_putc(m, '\n');

}

/* Print out the free pages at each order for each migratetype */

static int pagetypeinfo_showblockcount(struct seq_file *m, void *arg)

{

        int mtype;

        pg_data_t *pgdat = (pg_data_t *)arg;

        seq_printf(m, "\n%-23s", "Number of blocks type ");

        for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)

                seq_printf(m, "%12s ", migratetype_names[mtype]);

        seq_putc(m, '\n');

        walk_zones_in_node(m, pgdat, pagetypeinfo_showblockcount_print);

        return 0;

}

/*

 * This prints out statistics in relation to grouping pages by mobility.

 * It is expensive to collect so do not constantly read the file.

 */

static int pagetypeinfo_show(struct seq_file *m, void *arg)

{

        pg_data_t *pgdat = (pg_data_t *)arg;

        seq_printf(m, "Page block order: %d\n", pageblock_order);

        seq_printf(m, "Pages per block:  %lu\n", pageblock_nr_pages);

        seq_putc(m, '\n');

        pagetypeinfo_showfree(m, pgdat);

        pagetypeinfo_showblockcount(m, pgdat);

        return 0;

}

const struct seq_operations fragmentation_op = {

        .start  = frag_start,

        .next   = frag_next,

        .stop   = frag_stop,

        .show   = frag_show,

};

const struct seq_operations pagetypeinfo_op = {

        .start  = frag_start,

        .next   = frag_next,

        .stop   = frag_stop,

        .show   = pagetypeinfo_show,

};

#ifdef CONFIG_ZONE_DMA

#define TEXT_FOR_DMA(xx) xx "_dma",

#else

#define TEXT_FOR_DMA(xx)

#endif

#ifdef CONFIG_ZONE_DMA32

#define TEXT_FOR_DMA32(xx) xx "_dma32",

#else

#define TEXT_FOR_DMA32(xx)

#endif

#ifdef CONFIG_HIGHMEM

#define TEXT_FOR_HIGHMEM(xx) xx "_high",

#else

#define TEXT_FOR_HIGHMEM(xx)

#endif

#define TEXTS_FOR_ZONES(xx) TEXT_FOR_DMA(xx) TEXT_FOR_DMA32(xx) xx "_normal", \

                                        TEXT_FOR_HIGHMEM(xx) xx "_movable",

static const char * const vmstat_text[] = {

        /* Zoned VM counters */

        "nr_free_pages",

        "nr_inactive",

        "nr_active",

        "nr_anon_pages",

        "nr_mapped",

        "nr_file_pages",

        "nr_dirty",

        "nr_writeback",

        "nr_slab_reclaimable",

        "nr_slab_unreclaimable",

        "nr_page_table_pages",

        "nr_unstable",

        "nr_bounce",

        "nr_vmscan_write",

#ifdef CONFIG_NUMA

        "numa_hit",

        "numa_miss",

        "numa_foreign",

        "numa_interleave",

        "numa_local",

        "numa_other",

#endif

#ifdef CONFIG_VM_EVENT_COUNTERS

        "pgpgin",

        "pgpgout",

        "pswpin",

        "pswpout",

        TEXTS_FOR_ZONES("pgalloc")

        "pgfree",

        "pgactivate",

        "pgdeactivate",

        "pgfault",

        "pgmajfault",

        TEXTS_FOR_ZONES("pgrefill")

        TEXTS_FOR_ZONES("pgsteal")

        TEXTS_FOR_ZONES("pgscan_kswapd")

        TEXTS_FOR_ZONES("pgscan_direct")

        "pginodesteal",

        "slabs_scanned",

        "kswapd_steal",

        "kswapd_inodesteal",

        "pageoutrun",

        "allocstall",

        "pgrotated",

#endif

};

static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat,

                                                        struct zone *zone)

{

        int i;

        seq_printf(m, "Node %d, zone %8s", pgdat->node_id, zone->name);

        seq_printf(m,

                   "\n  pages free     %lu"

                   "\n        min      %lu"

                   "\n        low      %lu"

                   "\n        high     %lu"

                   "\n        scanned  %lu (a: %lu i: %lu)"

                   "\n        spanned  %lu"

                   "\n        present  %lu",

                   zone_page_state(zone, NR_FREE_PAGES),

                   zone->pages_min,

                   zone->pages_low,

                   zone->pages_high,

                   zone->pages_scanned,

                   zone->nr_scan_active, zone->nr_scan_inactive,

                   zone->spanned_pages,

                   zone->present_pages);

        for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)

                seq_printf(m, "\n    %-12s %lu", vmstat_text[i],

                                zone_page_state(zone, i));

        seq_printf(m,

                   "\n        protection: (%lu",

                   zone->lowmem_reserve[0]);

        for (i = 1; i < ARRAY_SIZE(zone->lowmem_reserve); i++)

                seq_printf(m, ", %lu", zone->lowmem_reserve[i]);

        seq_printf(m,

                   ")"

                   "\n  pagesets");

        for_each_online_cpu(i) {

                struct per_cpu_pageset *pageset;

                int j;

                pageset = zone_pcp(zone, i);

                for (j = 0; j < ARRAY_SIZE(pageset->pcp); j++) {

                        seq_printf(m,

                                   "\n    cpu: %i pcp: %i"

                                   "\n              count: %i"

                                   "\n              high:  %i"

                                   "\n              batch: %i",

                                   i, j,

                                   pageset->pcp[j].count,

                                   pageset->pcp[j].high,