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Diffstat (limited to 'mm/vmstat.c')
| -rw-r--r-- | mm/vmstat.c | 1702 |
1 files changed, 1702 insertions, 0 deletions
diff --git a/mm/vmstat.c b/mm/vmstat.c new file mode 100644 index 000000000..095cc4bc3 --- /dev/null +++ b/mm/vmstat.c @@ -0,0 +1,1702 @@ +/* + * 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> + * Copyright (C) 2008-2014 Christoph Lameter + */ +#include <linux/fs.h> +#include <linux/mm.h> +#include <linux/err.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/cpu.h> +#include <linux/cpumask.h> +#include <linux/vmstat.h> +#include <linux/proc_fs.h> +#include <linux/seq_file.h> +#include <linux/debugfs.h> +#include <linux/sched.h> +#include <linux/math64.h> +#include <linux/writeback.h> +#include <linux/compaction.h> +#include <linux/mm_inline.h> +#include <linux/page_ext.h> +#include <linux/page_owner.h> + +#include "internal.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) +{ + int cpu; + int i; + + memset(ret, 0, NR_VM_EVENT_ITEMS * sizeof(unsigned long)); + + for_each_online_cpu(cpu) { + struct vm_event_state *this = &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) +{ + get_online_cpus(); + sum_vm_events(ret); + put_online_cpus(); +} +EXPORT_SYMBOL_GPL(all_vm_events); + +/* + * 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_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] __cacheline_aligned_in_smp; +EXPORT_SYMBOL(vm_stat); + +#ifdef CONFIG_SMP + +int calculate_pressure_threshold(struct zone *zone) +{ + int threshold; + int watermark_distance; + + /* + * As vmstats are not up to date, there is drift between the estimated + * and real values. For high thresholds and a high number of CPUs, it + * is possible for the min watermark to be breached while the estimated + * value looks fine. The pressure threshold is a reduced value such + * that even the maximum amount of drift will not accidentally breach + * the min watermark + */ + watermark_distance = low_wmark_pages(zone) - min_wmark_pages(zone); + threshold = max(1, (int)(watermark_distance / num_online_cpus())); + + /* + * Maximum threshold is 125 + */ + threshold = min(125, threshold); + + return threshold; +} + +int calculate_normal_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->managed_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. + */ +void refresh_zone_stat_thresholds(void) +{ + struct zone *zone; + int cpu; + int threshold; + + for_each_populated_zone(zone) { + unsigned long max_drift, tolerate_drift; + + threshold = calculate_normal_threshold(zone); + + for_each_online_cpu(cpu) + per_cpu_ptr(zone->pageset, cpu)->stat_threshold + = threshold; + + /* + * Only set percpu_drift_mark if there is a danger that + * NR_FREE_PAGES reports the low watermark is ok when in fact + * the min watermark could be breached by an allocation + */ + tolerate_drift = low_wmark_pages(zone) - min_wmark_pages(zone); + max_drift = num_online_cpus() * threshold; + if (max_drift > tolerate_drift) + zone->percpu_drift_mark = high_wmark_pages(zone) + + max_drift; + } +} + +void set_pgdat_percpu_threshold(pg_data_t *pgdat, + int (*calculate_pressure)(struct zone *)) +{ + struct zone *zone; + int cpu; + int threshold; + int i; + + for (i = 0; i < pgdat->nr_zones; i++) { + zone = &pgdat->node_zones[i]; + if (!zone->percpu_drift_mark) + continue; + + threshold = (*calculate_pressure)(zone); + for_each_online_cpu(cpu) + per_cpu_ptr(zone->pageset, cpu)->stat_threshold + = threshold; + } +} + +/* + * For use when we know that interrupts are disabled, + * or when we know that preemption is disabled and that + * particular counter cannot be updated from interrupt context. + */ +void __mod_zone_page_state(struct zone *zone, enum zone_stat_item item, + int delta) +{ + struct per_cpu_pageset __percpu *pcp = zone->pageset; + s8 __percpu *p = pcp->vm_stat_diff + item; + long x; + long t; + + x = delta + __this_cpu_read(*p); + + t = __this_cpu_read(pcp->stat_threshold); + + if (unlikely(x > t || x < -t)) { + zone_page_state_add(x, zone, item); + x = 0; + } + __this_cpu_write(*p, x); +} +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 __percpu *pcp = zone->pageset; + s8 __percpu *p = pcp->vm_stat_diff + item; + s8 v, t; + + v = __this_cpu_inc_return(*p); + t = __this_cpu_read(pcp->stat_threshold); + if (unlikely(v > t)) { + s8 overstep = t >> 1; + + zone_page_state_add(v + overstep, zone, item); + __this_cpu_write(*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 __percpu *pcp = zone->pageset; + s8 __percpu *p = pcp->vm_stat_diff + item; + s8 v, t; + + v = __this_cpu_dec_return(*p); + t = __this_cpu_read(pcp->stat_threshold); + if (unlikely(v < - t)) { + s8 overstep = t >> 1; + + zone_page_state_add(v - overstep, zone, item); + __this_cpu_write(*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); + +#ifdef CONFIG_HAVE_CMPXCHG_LOCAL +/* + * If we have cmpxchg_local support then we do not need to incur the overhead + * that comes with local_irq_save/restore if we use this_cpu_cmpxchg. + * + * mod_state() modifies the zone counter state through atomic per cpu + * operations. + * + * Overstep mode specifies how overstep should handled: + * 0 No overstepping + * 1 Overstepping half of threshold + * -1 Overstepping minus half of threshold +*/ +static inline void mod_state(struct zone *zone, + enum zone_stat_item item, int delta, int overstep_mode) +{ + struct per_cpu_pageset __percpu *pcp = zone->pageset; + s8 __percpu *p = pcp->vm_stat_diff + item; + long o, n, t, z; + + do { + z = 0; /* overflow to zone counters */ + + /* + * The fetching of the stat_threshold is racy. We may apply + * a counter threshold to the wrong the cpu if we get + * rescheduled while executing here. However, the next + * counter update will apply the threshold again and + * therefore bring the counter under the threshold again. + * + * Most of the time the thresholds are the same anyways + * for all cpus in a zone. + */ + t = this_cpu_read(pcp->stat_threshold); + + o = this_cpu_read(*p); + n = delta + o; + + if (n > t || n < -t) { + int os = overstep_mode * (t >> 1) ; + + /* Overflow must be added to zone counters */ + z = n + os; + n = -os; + } + } while (this_cpu_cmpxchg(*p, o, n) != o); + + if (z) + zone_page_state_add(z, zone, item); +} + +void mod_zone_page_state(struct zone *zone, enum zone_stat_item item, + int delta) +{ + mod_state(zone, item, delta, 0); +} +EXPORT_SYMBOL(mod_zone_page_state); + +void inc_zone_state(struct zone *zone, enum zone_stat_item item) +{ + mod_state(zone, item, 1, 1); +} + +void inc_zone_page_state(struct page *page, enum zone_stat_item item) +{ + mod_state(page_zone(page), item, 1, 1); +} +EXPORT_SYMBOL(inc_zone_page_state); + +void dec_zone_page_state(struct page *page, enum zone_stat_item item) +{ + mod_state(page_zone(page), item, -1, -1); +} +EXPORT_SYMBOL(dec_zone_page_state); +#else +/* + * Use interrupt disable to serialize counter updates + */ +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); + +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); +#endif + + +/* + * Fold a differential into the global counters. + * Returns the number of counters updated. + */ +static int fold_diff(int *diff) +{ + int i; + int changes = 0; + + for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) + if (diff[i]) { + atomic_long_add(diff[i], &vm_stat[i]); + changes++; + } + return changes; +} + +/* + * Update the zone counters for the current 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. + * + * The function returns the number of global counters updated. + */ +static int refresh_cpu_vm_stats(void) +{ + struct zone *zone; + int i; + int global_diff[NR_VM_ZONE_STAT_ITEMS] = { 0, }; + int changes = 0; + + for_each_populated_zone(zone) { + struct per_cpu_pageset __percpu *p = zone->pageset; + + for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) { + int v; + + v = this_cpu_xchg(p->vm_stat_diff[i], 0); + if (v) { + + atomic_long_add(v, &zone->vm_stat[i]); + global_diff[i] += v; +#ifdef CONFIG_NUMA + /* 3 seconds idle till flush */ + __this_cpu_write(p->expire, 3); +#endif + } + } + cond_resched(); +#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 (!__this_cpu_read(p->expire) || + !__this_cpu_read(p->pcp.count)) + continue; + + /* + * We never drain zones local to this processor. + */ + if (zone_to_nid(zone) == numa_node_id()) { + __this_cpu_write(p->expire, 0); + continue; + } + + if (__this_cpu_dec_return(p->expire)) + continue; + + if (__this_cpu_read(p->pcp.count)) { + drain_zone_pages(zone, this_cpu_ptr(&p->pcp)); + changes++; + } +#endif + } + changes += fold_diff(global_diff); + return changes; +} + +/* + * Fold the data for an offline cpu into the global array. + * There cannot be any access by the offline cpu and therefore + * synchronization is simplified. + */ +void cpu_vm_stats_fold(int cpu) +{ + struct zone *zone; + int i; + int global_diff[NR_VM_ZONE_STAT_ITEMS] = { 0, }; + + for_each_populated_zone(zone) { + struct per_cpu_pageset *p; + + p = per_cpu_ptr(zone->pageset, cpu); + + for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) + if (p->vm_stat_diff[i]) { + int v; + + v = p->vm_stat_diff[i]; + p->vm_stat_diff[i] = 0; + atomic_long_add(v, &zone->vm_stat[i]); + global_diff[i] += v; + } + } + + fold_diff(global_diff); +} + +/* + * this is only called if !populated_zone(zone), which implies no other users of + * pset->vm_stat_diff[] exsist. + */ +void drain_zonestat(struct zone *zone, struct per_cpu_pageset *pset) +{ + int i; + + for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) + if (pset->vm_stat_diff[i]) { + int v = pset->vm_stat_diff[i]; + pset->vm_stat_diff[i] = 0; + atomic_long_add(v, &zone->vm_stat[i]); + atomic_long_add(v, &vm_stat[i]); + } +} +#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. + * + * When __GFP_OTHER_NODE is set assume the node of the preferred + * zone is the local node. This is useful for daemons who allocate + * memory on behalf of other processes. + */ +void zone_statistics(struct zone *preferred_zone, struct zone *z, gfp_t flags) +{ + if (z->zone_pgdat == preferred_zone->zone_pgdat) { + __inc_zone_state(z, NUMA_HIT); + } else { + __inc_zone_state(z, NUMA_MISS); + __inc_zone_state(preferred_zone, NUMA_FOREIGN); + } + if (z->node == ((flags & __GFP_OTHER_NODE) ? + preferred_zone->node : numa_node_id())) + __inc_zone_state(z, NUMA_LOCAL); + else + __inc_zone_state(z, NUMA_OTHER); +} +#endif + +#ifdef CONFIG_COMPACTION + +struct contig_page_info { + unsigned long free_pages; + unsigned long free_blocks_total; + unsigned long free_blocks_suitable; +}; + +/* + * Calculate the number of free pages in a zone, how many contiguous + * pages are free and how many are large enough to satisfy an allocation of + * the target size. Note that this function makes no attempt to estimate + * how many suitable free blocks there *might* be if MOVABLE pages were + * migrated. Calculating that is possible, but expensive and can be + * figured out from userspace + */ +static void fill_contig_page_info(struct zone *zone, + unsigned int suitable_order, + struct contig_page_info *info) +{ + unsigned int order; + + info->free_pages = 0; + info->free_blocks_total = 0; + info->free_blocks_suitable = 0; + + for (order = 0; order < MAX_ORDER; order++) { + unsigned long blocks; + + /* Count number of free blocks */ + blocks = zone->free_area[order].nr_free; + info->free_blocks_total += blocks; + + /* Count free base pages */ + info->free_pages += blocks << order; + + /* Count the suitable free blocks */ + if (order >= suitable_order) + info->free_blocks_suitable += blocks << + (order - suitable_order); + } +} + +/* + * A fragmentation index only makes sense if an allocation of a requested + * size would fail. If that is true, the fragmentation index indicates + * whether external fragmentation or a lack of memory was the problem. + * The value can be used to determine if page reclaim or compaction + * should be used + */ +static int __fragmentation_index(unsigned int order, struct contig_page_info *info) +{ + unsigned long requested = 1UL << order; + + if (!info->free_blocks_total) + return 0; + + /* Fragmentation index only makes sense when a request would fail */ + if (info->free_blocks_suitable) + return -1000; + + /* + * Index is between 0 and 1 so return within 3 decimal places + * + * 0 => allocation would fail due to lack of memory + * 1 => allocation would fail due to fragmentation + */ + return 1000 - div_u64( (1000+(div_u64(info->free_pages * 1000ULL, requested))), info->free_blocks_total); +} + +/* Same as __fragmentation index but allocs contig_page_info on stack */ +int fragmentation_index(struct zone *zone, unsigned int order) +{ + struct contig_page_info info; + + fill_contig_page_info(zone, order, &info); + return __fragmentation_index(order, &info); +} +#endif + +#if defined(CONFIG_PROC_FS) || defined(CONFIG_SYSFS) || defined(CONFIG_NUMA) +#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", + +const char * const vmstat_text[] = { + /* enum zone_stat_item countes */ + "nr_free_pages", + "nr_alloc_batch", + "nr_inactive_anon", + "nr_active_anon", + "nr_inactive_file", + "nr_active_file", + "nr_unevictable", + "nr_mlock", + "nr_anon_pages", + "nr_mapped", + "nr_file_pages", + "nr_dirty", + "nr_writeback", + "nr_slab_reclaimable", + "nr_slab_unreclaimable", + "nr_page_table_pages", + "nr_kernel_stack", + "nr_unstable", + "nr_bounce", + "nr_vmscan_write", + "nr_vmscan_immediate_reclaim", + "nr_writeback_temp", + "nr_isolated_anon", + "nr_isolated_file", + "nr_shmem", + "nr_dirtied", + "nr_written", + "nr_pages_scanned", + +#ifdef CONFIG_NUMA + "numa_hit", + "numa_miss", + "numa_foreign", + "numa_interleave", + "numa_local", + "numa_other", +#endif + "workingset_refault", + "workingset_activate", + "workingset_nodereclaim", + "nr_anon_transparent_hugepages", + "nr_free_cma", + +#ifdef CONFIG_UKSM + "nr_uksm_zero_pages", +#endif + /* enum writeback_stat_item counters */ + "nr_dirty_threshold", + "nr_dirty_background_threshold", + +#ifdef CONFIG_VM_EVENT_COUNTERS + /* enum vm_event_item counters */ + "pgpgin", + "pgpgout", + "pswpin", + "pswpout", + + TEXTS_FOR_ZONES("pgalloc") + + "pgfree", + "pgactivate", + "pgdeactivate", + + "pgfault", + "pgmajfault", + + TEXTS_FOR_ZONES("pgrefill") + TEXTS_FOR_ZONES("pgsteal_kswapd") + TEXTS_FOR_ZONES("pgsteal_direct") + TEXTS_FOR_ZONES("pgscan_kswapd") + TEXTS_FOR_ZONES("pgscan_direct") + "pgscan_direct_throttle", + +#ifdef CONFIG_NUMA + "zone_reclaim_failed", +#endif + "pginodesteal", + "slabs_scanned", + "kswapd_inodesteal", + "kswapd_low_wmark_hit_quickly", + "kswapd_high_wmark_hit_quickly", + "pageoutrun", + "allocstall", + + "pgrotated", + + "drop_pagecache", + "drop_slab", + +#ifdef CONFIG_NUMA_BALANCING + "numa_pte_updates", + "numa_huge_pte_updates", + "numa_hint_faults", + "numa_hint_faults_local", + "numa_pages_migrated", +#endif +#ifdef CONFIG_MIGRATION + "pgmigrate_success", + "pgmigrate_fail", +#endif +#ifdef CONFIG_COMPACTION + "compact_migrate_scanned", + "compact_free_scanned", + "compact_isolated", + "compact_stall", + "compact_fail", + "compact_success", +#endif + +#ifdef CONFIG_HUGETLB_PAGE + "htlb_buddy_alloc_success", + "htlb_buddy_alloc_fail", +#endif + "unevictable_pgs_culled", + "unevictable_pgs_scanned", + "unevictable_pgs_rescued", + "unevictable_pgs_mlocked", + "unevictable_pgs_munlocked", + "unevictable_pgs_cleared", + "unevictable_pgs_stranded", + +#ifdef CONFIG_TRANSPARENT_HUGEPAGE + "thp_fault_alloc", + "thp_fault_fallback", + "thp_collapse_alloc", + "thp_collapse_alloc_failed", + "thp_split", + "thp_zero_page_alloc", + "thp_zero_page_alloc_failed", +#endif +#ifdef CONFIG_MEMORY_BALLOON + "balloon_inflate", + "balloon_deflate", +#ifdef CONFIG_BALLOON_COMPACTION + "balloon_migrate", +#endif +#endif /* CONFIG_MEMORY_BALLOON */ +#ifdef CONFIG_DEBUG_TLBFLUSH +#ifdef CONFIG_SMP + "nr_tlb_remote_flush", + "nr_tlb_remote_flush_received", +#endif /* CONFIG_SMP */ + "nr_tlb_local_flush_all", + "nr_tlb_local_flush_one", +#endif /* CONFIG_DEBUG_TLBFLUSH */ + +#ifdef CONFIG_DEBUG_VM_VMACACHE + "vmacache_find_calls", + "vmacache_find_hits", + "vmacache_full_flushes", +#endif +#endif /* CONFIG_VM_EVENTS_COUNTERS */ +}; +#endif /* CONFIG_PROC_FS || CONFIG_SYSFS || CONFIG_NUMA */ + + +#if (defined(CONFIG_DEBUG_FS) && defined(CONFIG_COMPACTION)) || \ + defined(CONFIG_PROC_FS) +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); + } +} +#endif + +#ifdef CONFIG_PROC_FS +static char * const migratetype_names[MIGRATE_TYPES] = { + "Unmovable", + "Reclaimable", + "Movable", + "Reserve", +#ifdef CONFIG_CMA + "CMA", +#endif +#ifdef CONFIG_MEMORY_ISOLATION + "Isolate", +#endif +}; + +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 = zone_end_pfn(zone); + 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); + + /* Watch for unexpected holes punched in the memmap */ + if (!memmap_valid_within(pfn, page, zone)) + continue; + + mtype = get_pageblock_migratetype(page); + + if (mtype < MIGRATE_TYPES) + 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; +} + +#ifdef CONFIG_PAGE_OWNER +static void pagetypeinfo_showmixedcount_print(struct seq_file *m, + pg_data_t *pgdat, + struct zone *zone) +{ + struct page *page; + struct page_ext *page_ext; + unsigned long pfn = zone->zone_start_pfn, block_end_pfn; + unsigned long end_pfn = pfn + zone->spanned_pages; + unsigned long count[MIGRATE_TYPES] = { 0, }; + int pageblock_mt, page_mt; + int i; + + /* Scan block by block. First and last block may be incomplete */ + pfn = zone->zone_start_pfn; + + /* + * Walk the zone in pageblock_nr_pages steps. If a page block spans + * a zone boundary, it will be double counted between zones. This does + * not matter as the mixed block count will still be correct + */ + for (; pfn < end_pfn; ) { + if (!pfn_valid(pfn)) { + pfn = ALIGN(pfn + 1, MAX_ORDER_NR_PAGES); + continue; + } + + block_end_pfn = ALIGN(pfn + 1, pageblock_nr_pages); + block_end_pfn = min(block_end_pfn, end_pfn); + + page = pfn_to_page(pfn); + pageblock_mt = get_pfnblock_migratetype(page, pfn); + + for (; pfn < block_end_pfn; pfn++) { + if (!pfn_valid_within(pfn)) + continue; + + page = pfn_to_page(pfn); + if (PageBuddy(page)) { + pfn += (1UL << page_order(page)) - 1; + continue; + } + + if (PageReserved(page)) + continue; + + page_ext = lookup_page_ext(page); + + if (!test_bit(PAGE_EXT_OWNER, &page_ext->flags)) + continue; + + page_mt = gfpflags_to_migratetype(page_ext->gfp_mask); + if (pageblock_mt != page_mt) { + if (is_migrate_cma(pageblock_mt)) + count[MIGRATE_MOVABLE]++; + else + count[pageblock_mt]++; + + pfn = block_end_pfn; + break; + } + pfn += (1UL << page_ext->order) - 1; + } + } + + /* Print counts */ + seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name); + for (i = 0; i < MIGRATE_TYPES; i++) + seq_printf(m, "%12lu ", count[i]); + seq_putc(m, '\n'); +} +#endif /* CONFIG_PAGE_OWNER */ + +/* + * Print out the number of pageblocks for each migratetype that contain pages + * of other types. This gives an indication of how well fallbacks are being + * contained by rmqueue_fallback(). It requires information from PAGE_OWNER + * to determine what is going on + */ +static void pagetypeinfo_showmixedcount(struct seq_file *m, pg_data_t *pgdat) +{ +#ifdef CONFIG_PAGE_OWNER + int mtype; + + if (!page_owner_inited) + return; + + drain_all_pages(NULL); + + seq_printf(m, "\n%-23s", "Number of mixed blocks "); + 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_showmixedcount_print); +#endif /* CONFIG_PAGE_OWNER */ +} + +/* + * 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; + + /* check memoryless node */ + if (!node_state(pgdat->node_id, N_MEMORY)) + return 0; + + 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); + pagetypeinfo_showmixedcount(m, pgdat); + + return 0; +} + +static const struct seq_operations fragmentation_op = { + .start = frag_start, + .next = frag_next, + .stop = frag_stop, + .show = frag_show, +}; + +static int fragmentation_open(struct inode *inode, struct file *file) +{ + return seq_open(file, &fragmentation_op); +} + +static const struct file_operations fragmentation_file_operations = { + .open = fragmentation_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release, +}; + +static const struct seq_operations pagetypeinfo_op = { + .start = frag_start, + .next = frag_next, + .stop = frag_stop, + .show = pagetypeinfo_show, +}; + +static int pagetypeinfo_open(struct inode *inode, struct file *file) +{ + return seq_open(file, &pagetypeinfo_op); +} + +static const struct file_operations pagetypeinfo_file_ops = { + .open = pagetypeinfo_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release, +}; + +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" + "\n spanned %lu" + "\n present %lu" + "\n managed %lu", + zone_page_state(zone, NR_FREE_PAGES), + min_wmark_pages(zone), + low_wmark_pages(zone), + high_wmark_pages(zone), + zone_page_state(zone, NR_PAGES_SCANNED), + zone->spanned_pages, + zone->present_pages, + zone->managed_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: (%ld", + zone->lowmem_reserve[0]); + for (i = 1; i < ARRAY_SIZE(zone->lowmem_reserve); i++) + seq_printf(m, ", %ld", zone->lowmem_reserve[i]); + seq_printf(m, + ")" + "\n pagesets"); + for_each_online_cpu(i) { + struct per_cpu_pageset *pageset; + + pageset = per_cpu_ptr(zone->pageset, i); + seq_printf(m, + "\n cpu: %i" + "\n count: %i" + "\n high: %i" + "\n batch: %i", + i, + pageset->pcp.count, + pageset->pcp.high, + pageset->pcp.batch); +#ifdef CONFIG_SMP + seq_printf(m, "\n vm stats threshold: %d", + pageset->stat_threshold); +#endif + } + seq_printf(m, + "\n all_unreclaimable: %u" + "\n start_pfn: %lu" + "\n inactive_ratio: %u", + !zone_reclaimable(zone), + zone->zone_start_pfn, + zone->inactive_ratio); + seq_putc(m, '\n'); +} + +/* + * Output information about zones in @pgdat. + */ +static int zoneinfo_show(struct seq_file *m, void *arg) +{ + pg_data_t *pgdat = (pg_data_t *)arg; + walk_zones_in_node(m, pgdat, zoneinfo_show_print); + return 0; +} + +static const struct seq_operations zoneinfo_op = { + .start = frag_start, /* iterate over all zones. The same as in + * fragmentation. */ + .next = frag_next, + .stop = frag_stop, + .show = zoneinfo_show, +}; + +static int zoneinfo_open(struct inode *inode, struct file *file) +{ + return seq_open(file, &zoneinfo_op); +} + +static const struct file_operations proc_zoneinfo_file_operations = { + .open = zoneinfo_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release, +}; + +enum writeback_stat_item { + NR_DIRTY_THRESHOLD, + NR_DIRTY_BG_THRESHOLD, + NR_VM_WRITEBACK_STAT_ITEMS, +}; + +static void *vmstat_start(struct seq_file *m, loff_t *pos) +{ + unsigned long *v; + int i, stat_items_size; + + if (*pos >= ARRAY_SIZE(vmstat_text)) + return NULL; + stat_items_size = NR_VM_ZONE_STAT_ITEMS * sizeof(unsigned long) + + NR_VM_WRITEBACK_STAT_ITEMS * sizeof(unsigned long); + +#ifdef CONFIG_VM_EVENT_COUNTERS + stat_items_size += sizeof(struct vm_event_state); +#endif + + v = kmalloc(stat_items_size, GFP_KERNEL); + m->private = v; + if (!v) + return ERR_PTR(-ENOMEM); + for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) + v[i] = global_page_state(i); + v += NR_VM_ZONE_STAT_ITEMS; + + global_dirty_limits(v + NR_DIRTY_BG_THRESHOLD, + v + NR_DIRTY_THRESHOLD); + v += NR_VM_WRITEBACK_STAT_ITEMS; + +#ifdef CONFIG_VM_EVENT_COUNTERS + all_vm_events(v); + v[PGPGIN] /= 2; /* sectors -> kbytes */ + v[PGPGOUT] /= 2; +#endif + return (unsigned long *)m->private + *pos; +} + +static void *vmstat_next(struct seq_file *m, void *arg, loff_t *pos) +{ + (*pos)++; + if (*pos >= ARRAY_SIZE(vmstat_text)) + return NULL; + return (unsigned long *)m->private + *pos; +} + +static int vmstat_show(struct seq_file *m, void *arg) +{ + unsigned long *l = arg; + unsigned long off = l - (unsigned long *)m->private; + + seq_printf(m, "%s %lu\n", vmstat_text[off], *l); + return 0; +} + +static void vmstat_stop(struct seq_file *m, void *arg) +{ + kfree(m->private); + m->private = NULL; +} + +static const struct seq_operations vmstat_op = { + .start = vmstat_start, + .next = vmstat_next, + .stop = vmstat_stop, + .show = vmstat_show, +}; + +static int vmstat_open(struct inode *inode, struct file *file) +{ + return seq_open(file, &vmstat_op); +} + +static const struct file_operations proc_vmstat_file_operations = { + .open = vmstat_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release, +}; +#endif /* CONFIG_PROC_FS */ + +#ifdef CONFIG_SMP +static DEFINE_PER_CPU(struct delayed_work, vmstat_work); +int sysctl_stat_interval __read_mostly = HZ; +static cpumask_var_t cpu_stat_off; + +static void vmstat_update(struct work_struct *w) +{ + if (refresh_cpu_vm_stats()) + /* + * Counters were updated so we expect more updates + * to occur in the future. Keep on running the + * update worker thread. + */ + schedule_delayed_work(this_cpu_ptr(&vmstat_work), + round_jiffies_relative(sysctl_stat_interval)); + else { + /* + * We did not update any counters so the app may be in + * a mode where it does not cause counter updates. + * We may be uselessly running vmstat_update. + * Defer the checking for differentials to the + * shepherd thread on a different processor. + */ + int r; + /* + * Shepherd work thread does not race since it never + * changes the bit if its zero but the cpu + * online / off line code may race if + * worker threads are still allowed during + * shutdown / startup. + */ + r = cpumask_test_and_set_cpu(smp_processor_id(), + cpu_stat_off); + VM_BUG_ON(r); + } +} + +/* + * Check if the diffs for a certain cpu indicate that + * an update is needed. + */ +static bool need_update(int cpu) +{ + struct zone *zone; + + for_each_populated_zone(zone) { + struct per_cpu_pageset *p = per_cpu_ptr(zone->pageset, cpu); + + BUILD_BUG_ON(sizeof(p->vm_stat_diff[0]) != 1); + /* + * The fast way of checking if there are any vmstat diffs. + * This works because the diffs are byte sized items. + */ + if (memchr_inv(p->vm_stat_diff, 0, NR_VM_ZONE_STAT_ITEMS)) + return true; + + } + return false; +} + + +/* + * Shepherd worker thread that checks the + * differentials of processors that have their worker + * threads for vm statistics updates disabled because of + * inactivity. + */ +static void vmstat_shepherd(struct work_struct *w); + +static DECLARE_DELAYED_WORK(shepherd, vmstat_shepherd); + +static void vmstat_shepherd(struct work_struct *w) +{ + int cpu; + + get_online_cpus(); + /* Check processors whose vmstat worker threads have been disabled */ + for_each_cpu(cpu, cpu_stat_off) + if (need_update(cpu) && + cpumask_test_and_clear_cpu(cpu, cpu_stat_off)) + + schedule_delayed_work_on(cpu, + &per_cpu(vmstat_work, cpu), 0); + + put_online_cpus(); + + schedule_delayed_work(&shepherd, + round_jiffies_relative(sysctl_stat_interval)); + +} + +static void __init start_shepherd_timer(void) +{ + int cpu; + + for_each_possible_cpu(cpu) + INIT_DELAYED_WORK(per_cpu_ptr(&vmstat_work, cpu), + vmstat_update); + + if (!alloc_cpumask_var(&cpu_stat_off, GFP_KERNEL)) + BUG(); + cpumask_copy(cpu_stat_off, cpu_online_mask); + + schedule_delayed_work(&shepherd, + round_jiffies_relative(sysctl_stat_interval)); +} + +static void vmstat_cpu_dead(int node) +{ + int cpu; + + get_online_cpus(); + for_each_online_cpu(cpu) + if (cpu_to_node(cpu) == node) + goto end; + + node_clear_state(node, N_CPU); +end: + put_online_cpus(); +} + +/* + * Use the cpu notifier to insure that the thresholds are recalculated + * when necessary. + */ +static int vmstat_cpuup_callback(struct notifier_block *nfb, + unsigned long action, + void *hcpu) +{ + long cpu = (long)hcpu; + + switch (action) { + case CPU_ONLINE: + case CPU_ONLINE_FROZEN: + refresh_zone_stat_thresholds(); + node_set_state(cpu_to_node(cpu), N_CPU); + cpumask_set_cpu(cpu, cpu_stat_off); + break; + case CPU_DOWN_PREPARE: + case CPU_DOWN_PREPARE_FROZEN: + cancel_delayed_work_sync(&per_cpu(vmstat_work, cpu)); + cpumask_clear_cpu(cpu, cpu_stat_off); + break; + case CPU_DOWN_FAILED: + case CPU_DOWN_FAILED_FROZEN: + cpumask_set_cpu(cpu, cpu_stat_off); + break; + case CPU_DEAD: + case CPU_DEAD_FROZEN: + refresh_zone_stat_thresholds(); + vmstat_cpu_dead(cpu_to_node(cpu)); + break; + default: + break; + } + return NOTIFY_OK; +} + +static struct notifier_block vmstat_notifier = + { &vmstat_cpuup_callback, NULL, 0 }; +#endif + +static int __init setup_vmstat(void) +{ +#ifdef CONFIG_SMP + cpu_notifier_register_begin(); + __register_cpu_notifier(&vmstat_notifier); + + start_shepherd_timer(); + cpu_notifier_register_done(); +#endif +#ifdef CONFIG_PROC_FS + proc_create("buddyinfo", S_IRUGO, NULL, &fragmentation_file_operations); + proc_create("pagetypeinfo", S_IRUGO, NULL, &pagetypeinfo_file_ops); + proc_create("vmstat", S_IRUGO, NULL, &proc_vmstat_file_operations); + proc_create("zoneinfo", S_IRUGO, NULL, &proc_zoneinfo_file_operations); +#endif + return 0; +} +module_init(setup_vmstat) + +#if defined(CONFIG_DEBUG_FS) && defined(CONFIG_COMPACTION) + +/* + * Return an index indicating how much of the available free memory is + * unusable for an allocation of the requested size. + */ +static int unusable_free_index(unsigned int order, + struct contig_page_info *info) +{ + /* No free memory is interpreted as all free memory is unusable */ + if (info->free_pages == 0) + return 1000; + + /* + * Index should be a value between 0 and 1. Return a value to 3 + * decimal places. + * + * 0 => no fragmentation + * 1 => high fragmentation + */ + return div_u64((info->free_pages - (info->free_blocks_suitable << order)) * 1000ULL, info->free_pages); + +} + +static void unusable_show_print(struct seq_file *m, + pg_data_t *pgdat, struct zone *zone) +{ + unsigned int order; + int index; + struct contig_page_info info; + + seq_printf(m, "Node %d, zone %8s ", + pgdat->node_id, + zone->name); + for (order = 0; order < MAX_ORDER; ++order) { + fill_contig_page_info(zone, order, &info); + index = unusable_free_index(order, &info); + seq_printf(m, "%d.%03d ", index / 1000, index % 1000); + } + + seq_putc(m, '\n'); +} + +/* + * Display unusable free space index + * + * The unusable free space index measures how much of the available free + * memory cannot be used to satisfy an allocation of a given size and is a + * value between 0 and 1. The higher the value, the more of free memory is + * unusable and by implication, the worse the external fragmentation is. This + * can be expressed as a percentage by multiplying by 100. + */ +static int unusable_show(struct seq_file *m, void *arg) +{ + pg_data_t *pgdat = (pg_data_t *)arg; + + /* check memoryless node */ + if (!node_state(pgdat->node_id, N_MEMORY)) + return 0; + + walk_zones_in_node(m, pgdat, unusable_show_print); + + return 0; +} + +static const struct seq_operations unusable_op = { + .start = frag_start, + .next = frag_next, + .stop = frag_stop, + .show = unusable_show, +}; + +static int unusable_open(struct inode *inode, struct file *file) +{ + return seq_open(file, &unusable_op); +} + +static const struct file_operations unusable_file_ops = { + .open = unusable_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release, +}; + +static void extfrag_show_print(struct seq_file *m, + pg_data_t *pgdat, struct zone *zone) +{ + unsigned int order; + int index; + + /* Alloc on stack as interrupts are disabled for zone walk */ + struct contig_page_info info; + + seq_printf(m, "Node %d, zone %8s ", + pgdat->node_id, + zone->name); + for (order = 0; order < MAX_ORDER; ++order) { + fill_contig_page_info(zone, order, &info); + index = __fragmentation_index(order, &info); + seq_printf(m, "%d.%03d ", index / 1000, index % 1000); + } + + seq_putc(m, '\n'); +} + +/* + * Display fragmentation index for orders that allocations would fail for + */ +static int extfrag_show(struct seq_file *m, void *arg) +{ + pg_data_t *pgdat = (pg_data_t *)arg; + + walk_zones_in_node(m, pgdat, extfrag_show_print); + + return 0; +} + +static const struct seq_operations extfrag_op = { + .start = frag_start, + .next = frag_next, + .stop = frag_stop, + .show = extfrag_show, +}; + +static int extfrag_open(struct inode *inode, struct file *file) +{ + return seq_open(file, &extfrag_op); +} + +static const struct file_operations extfrag_file_ops = { + .open = extfrag_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release, +}; + +static int __init extfrag_debug_init(void) +{ + struct dentry *extfrag_debug_root; + + extfrag_debug_root = debugfs_create_dir("extfrag", NULL); + if (!extfrag_debug_root) + return -ENOMEM; + + if (!debugfs_create_file("unusable_index", 0444, + extfrag_debug_root, NULL, &unusable_file_ops)) + goto fail; + + if (!debugfs_create_file("extfrag_index", 0444, + extfrag_debug_root, NULL, &extfrag_file_ops)) + goto fail; + + return 0; +fail: + debugfs_remove_recursive(extfrag_debug_root); + return -ENOMEM; +} + +module_init(extfrag_debug_init); +#endif |