diff options
Diffstat (limited to 'mm/compaction.c')
| -rw-r--r-- | mm/compaction.c | 261 |
1 files changed, 130 insertions, 131 deletions
diff --git a/mm/compaction.c b/mm/compaction.c index 807b58e6eb68..3925cb61dbb8 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -23,6 +23,7 @@ #include <linux/freezer.h> #include <linux/page_owner.h> #include <linux/psi.h> +#include <linux/cpuset.h> #include "internal.h" #ifdef CONFIG_COMPACTION @@ -79,32 +80,13 @@ static inline bool is_via_compact_memory(int order) { return false; } #define COMPACTION_HPAGE_ORDER (PMD_SHIFT - PAGE_SHIFT) #endif -static void split_map_pages(struct list_head *freepages) +static struct page *mark_allocated_noprof(struct page *page, unsigned int order, gfp_t gfp_flags) { - unsigned int i, order; - struct page *page, *next; - LIST_HEAD(tmp_list); - - for (order = 0; order < NR_PAGE_ORDERS; order++) { - list_for_each_entry_safe(page, next, &freepages[order], lru) { - unsigned int nr_pages; - - list_del(&page->lru); - - nr_pages = 1 << order; - - post_alloc_hook(page, order, __GFP_MOVABLE); - if (order) - split_page(page, order); - - for (i = 0; i < nr_pages; i++) { - list_add(&page->lru, &tmp_list); - page++; - } - } - list_splice_init(&tmp_list, &freepages[0]); - } + post_alloc_hook(page, order, __GFP_MOVABLE); + set_page_refcounted(page); + return page; } +#define mark_allocated(...) alloc_hooks(mark_allocated_noprof(__VA_ARGS__)) static unsigned long release_free_list(struct list_head *freepages) { @@ -122,7 +104,7 @@ static unsigned long release_free_list(struct list_head *freepages) * Convert free pages into post allocation pages, so * that we can free them via __free_page. */ - post_alloc_hook(page, order, __GFP_MOVABLE); + mark_allocated(page, order, __GFP_MOVABLE); __free_pages(page, order); if (pfn > high_pfn) high_pfn = pfn; @@ -649,7 +631,8 @@ static unsigned long isolate_freepages_block(struct compact_control *cc, if (PageCompound(page)) { const unsigned int order = compound_order(page); - if (blockpfn + (1UL << order) <= end_pfn) { + if ((order <= MAX_PAGE_ORDER) && + (blockpfn + (1UL << order) <= end_pfn)) { blockpfn += (1UL << order) - 1; page += (1UL << order) - 1; nr_scanned += (1UL << order) - 1; @@ -735,11 +718,11 @@ isolate_fail: * * Non-free pages, invalid PFNs, or zone boundaries within the * [start_pfn, end_pfn) range are considered errors, cause function to - * undo its actions and return zero. + * undo its actions and return zero. cc->freepages[] are empty. * * Otherwise, function returns one-past-the-last PFN of isolated page * (which may be greater then end_pfn if end fell in a middle of - * a free page). + * a free page). cc->freepages[] contain free pages isolated. */ unsigned long isolate_freepages_range(struct compact_control *cc, @@ -747,10 +730,9 @@ isolate_freepages_range(struct compact_control *cc, { unsigned long isolated, pfn, block_start_pfn, block_end_pfn; int order; - struct list_head tmp_freepages[NR_PAGE_ORDERS]; for (order = 0; order < NR_PAGE_ORDERS; order++) - INIT_LIST_HEAD(&tmp_freepages[order]); + INIT_LIST_HEAD(&cc->freepages[order]); pfn = start_pfn; block_start_pfn = pageblock_start_pfn(pfn); @@ -781,7 +763,7 @@ isolate_freepages_range(struct compact_control *cc, break; isolated = isolate_freepages_block(cc, &isolate_start_pfn, - block_end_pfn, tmp_freepages, 0, true); + block_end_pfn, cc->freepages, 0, true); /* * In strict mode, isolate_freepages_block() returns 0 if @@ -800,13 +782,10 @@ isolate_freepages_range(struct compact_control *cc, if (pfn < end_pfn) { /* Loop terminated early, cleanup. */ - release_free_list(tmp_freepages); + release_free_list(cc->freepages); return 0; } - /* __isolate_free_page() does not map the pages */ - split_map_pages(tmp_freepages); - /* We don't use freelists for anything. */ return pfn; } @@ -1002,13 +981,13 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn, } if (PageHuge(page)) { + const unsigned int order = compound_order(page); /* * skip hugetlbfs if we are not compacting for pages * bigger than its order. THPs and other compound pages * are handled below. */ if (!cc->alloc_contig) { - const unsigned int order = compound_order(page); if (order <= MAX_PAGE_ORDER) { low_pfn += (1UL << order) - 1; @@ -1022,27 +1001,27 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn, locked = NULL; } - ret = isolate_or_dissolve_huge_page(page, &cc->migratepages); + folio = page_folio(page); + ret = isolate_or_dissolve_huge_folio(folio, &cc->migratepages); /* - * Fail isolation in case isolate_or_dissolve_huge_page() + * Fail isolation in case isolate_or_dissolve_huge_folio() * reports an error. In case of -ENOMEM, abort right away. */ if (ret < 0) { /* Do not report -EBUSY down the chain */ if (ret == -EBUSY) ret = 0; - low_pfn += compound_nr(page) - 1; - nr_scanned += compound_nr(page) - 1; + low_pfn += (1UL << order) - 1; + nr_scanned += (1UL << order) - 1; goto isolate_fail; } - if (PageHuge(page)) { + if (folio_test_hugetlb(folio)) { /* * Hugepage was successfully isolated and placed * on the cc->migratepages list. */ - folio = page_folio(page); low_pfn += folio_nr_pages(folio) - 1; goto isolate_success_no_list; } @@ -1172,22 +1151,22 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn, if (((mode & ISOLATE_ASYNC_MIGRATE) && is_dirty) || (mapping && is_unevictable)) { bool migrate_dirty = true; - bool is_unmovable; + bool is_inaccessible; /* * Only folios without mappings or that have * a ->migrate_folio callback are possible to migrate * without blocking. * - * Folios from unmovable mappings are not migratable. + * Folios from inaccessible mappings are not migratable. * * However, we can be racing with truncation, which can * free the mapping that we need to check. Truncation * holds the folio lock until after the folio is removed * from the page so holding it ourselves is sufficient. * - * To avoid locking the folio just to check unmovable, - * assume every unmovable folio is also unevictable, + * To avoid locking the folio just to check inaccessible, + * assume every inaccessible folio is also unevictable, * which is a cheaper test. If our assumption goes * wrong, it's not a correctness bug, just potentially * wasted cycles. @@ -1200,9 +1179,9 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn, migrate_dirty = !mapping || mapping->a_ops->migrate_folio; } - is_unmovable = mapping && mapping_unmovable(mapping); + is_inaccessible = mapping && mapping_inaccessible(mapping); folio_unlock(folio); - if (!migrate_dirty || is_unmovable) + if (!migrate_dirty || is_inaccessible) goto isolate_fail_put; } @@ -1851,7 +1830,7 @@ static void isolate_freepages(struct compact_control *cc) * This is a migrate-callback that "allocates" freepages by taking pages * from the isolated freelists in the block we are migrating to. */ -static struct folio *compaction_alloc(struct folio *src, unsigned long data) +static struct folio *compaction_alloc_noprof(struct folio *src, unsigned long data) { struct compact_control *cc = (struct compact_control *)data; struct folio *dst; @@ -1891,6 +1870,7 @@ again: dst = (struct folio *)freepage; post_alloc_hook(&dst->page, order, __GFP_MOVABLE); + set_page_refcounted(&dst->page); if (order) prep_compound_page(&dst->page, order); cc->nr_freepages -= 1 << order; @@ -1898,6 +1878,11 @@ again: return page_rmappable_folio(&dst->page); } +static struct folio *compaction_alloc(struct folio *src, unsigned long data) +{ + return alloc_hooks(compaction_alloc_noprof(src, data)); +} + /* * This is a migrate-callback that "frees" freepages back to the isolated * freelist. All pages on the freelist are from the same zone, so there is no @@ -2264,15 +2249,11 @@ static unsigned int fragmentation_score_node(pg_data_t *pgdat) static unsigned int fragmentation_score_wmark(bool low) { - unsigned int wmark_low; + unsigned int wmark_low, leeway; - /* - * Cap the low watermark to avoid excessive compaction - * activity in case a user sets the proactiveness tunable - * close to 100 (maximum). - */ - wmark_low = max(100U - sysctl_compaction_proactiveness, 5U); - return low ? wmark_low : min(wmark_low + 10, 100U); + wmark_low = 100U - sysctl_compaction_proactiveness; + leeway = min(10U, wmark_low / 2); + return low ? wmark_low : min(wmark_low + leeway, 100U); } static bool should_proactive_compact_node(pg_data_t *pgdat) @@ -2343,11 +2324,26 @@ static enum compact_result __compact_finished(struct compact_control *cc) if (!pageblock_aligned(cc->migrate_pfn)) return COMPACT_CONTINUE; + /* + * When defrag_mode is enabled, make kcompactd target + * watermarks in whole pageblocks. Because they can be stolen + * without polluting, no further fallback checks are needed. + */ + if (defrag_mode && !cc->direct_compaction) { + if (__zone_watermark_ok(cc->zone, cc->order, + high_wmark_pages(cc->zone), + cc->highest_zoneidx, cc->alloc_flags, + zone_page_state(cc->zone, + NR_FREE_PAGES_BLOCKS))) + return COMPACT_SUCCESS; + + return COMPACT_CONTINUE; + } + /* Direct compactor: Is a suitable page free? */ ret = COMPACT_NO_SUITABLE_PAGE; for (order = cc->order; order < NR_PAGE_ORDERS; order++) { struct free_area *area = &cc->zone->free_area[order]; - bool can_steal; /* Job done if page is free of the right migratetype */ if (!free_area_empty(area, migratetype)) @@ -2363,8 +2359,7 @@ static enum compact_result __compact_finished(struct compact_control *cc) * Job done if allocation would steal freepages from * other migratetype buddy lists. */ - if (find_suitable_fallback(area, order, migratetype, - true, &can_steal) != -1) + if (find_suitable_fallback(area, order, migratetype, true) >= 0) /* * Movable pages are OK in any pageblock. If we are * stealing for a non-movable allocation, make sure @@ -2396,40 +2391,42 @@ static enum compact_result compact_finished(struct compact_control *cc) } static bool __compaction_suitable(struct zone *zone, int order, - int highest_zoneidx, - unsigned long wmark_target) + unsigned long watermark, int highest_zoneidx, + unsigned long free_pages) { - unsigned long watermark; /* * Watermarks for order-0 must be met for compaction to be able to * isolate free pages for migration targets. This means that the - * watermark and alloc_flags have to match, or be more pessimistic than - * the check in __isolate_free_page(). We don't use the direct - * compactor's alloc_flags, as they are not relevant for freepage - * isolation. We however do use the direct compactor's highest_zoneidx - * to skip over zones where lowmem reserves would prevent allocation - * even if compaction succeeds. - * For costly orders, we require low watermark instead of min for - * compaction to proceed to increase its chances. + * watermark have to match, or be more pessimistic than the check in + * __isolate_free_page(). + * + * For costly orders, we require a higher watermark for compaction to + * proceed to increase its chances. + * + * We use the direct compactor's highest_zoneidx to skip over zones + * where lowmem reserves would prevent allocation even if compaction + * succeeds. + * * ALLOC_CMA is used, as pages in CMA pageblocks are considered - * suitable migration targets + * suitable migration targets. */ - watermark = (order > PAGE_ALLOC_COSTLY_ORDER) ? - low_wmark_pages(zone) : min_wmark_pages(zone); watermark += compact_gap(order); + if (order > PAGE_ALLOC_COSTLY_ORDER) + watermark += low_wmark_pages(zone) - min_wmark_pages(zone); return __zone_watermark_ok(zone, 0, watermark, highest_zoneidx, - ALLOC_CMA, wmark_target); + ALLOC_CMA, free_pages); } /* * compaction_suitable: Is this suitable to run compaction on this zone now? */ -bool compaction_suitable(struct zone *zone, int order, int highest_zoneidx) +bool compaction_suitable(struct zone *zone, int order, unsigned long watermark, + int highest_zoneidx) { enum compact_result compact_result; bool suitable; - suitable = __compaction_suitable(zone, order, highest_zoneidx, + suitable = __compaction_suitable(zone, order, watermark, highest_zoneidx, zone_page_state(zone, NR_FREE_PAGES)); /* * fragmentation index determines if allocation failures are due to @@ -2467,6 +2464,7 @@ bool compaction_suitable(struct zone *zone, int order, int highest_zoneidx) return suitable; } +/* Used by direct reclaimers */ bool compaction_zonelist_suitable(struct alloc_context *ac, int order, int alloc_flags) { @@ -2489,8 +2487,8 @@ bool compaction_zonelist_suitable(struct alloc_context *ac, int order, */ available = zone_reclaimable_pages(zone) / order; available += zone_page_state_snapshot(zone, NR_FREE_PAGES); - if (__compaction_suitable(zone, order, ac->highest_zoneidx, - available)) + if (__compaction_suitable(zone, order, min_wmark_pages(zone), + ac->highest_zoneidx, available)) return true; } @@ -2506,16 +2504,40 @@ bool compaction_zonelist_suitable(struct alloc_context *ac, int order, */ static enum compact_result compaction_suit_allocation_order(struct zone *zone, unsigned int order, - int highest_zoneidx, unsigned int alloc_flags) + int highest_zoneidx, unsigned int alloc_flags, + bool async, bool kcompactd) { + unsigned long free_pages; unsigned long watermark; + if (kcompactd && defrag_mode) + free_pages = zone_page_state(zone, NR_FREE_PAGES_BLOCKS); + else + free_pages = zone_page_state(zone, NR_FREE_PAGES); + watermark = wmark_pages(zone, alloc_flags & ALLOC_WMARK_MASK); - if (zone_watermark_ok(zone, order, watermark, highest_zoneidx, - alloc_flags)) + if (__zone_watermark_ok(zone, order, watermark, highest_zoneidx, + alloc_flags, free_pages)) return COMPACT_SUCCESS; - if (!compaction_suitable(zone, order, highest_zoneidx)) + /* + * For unmovable allocations (without ALLOC_CMA), check if there is enough + * free memory in the non-CMA pageblocks. Otherwise compaction could form + * the high-order page in CMA pageblocks, which would not help the + * allocation to succeed. However, limit the check to costly order async + * compaction (such as opportunistic THP attempts) because there is the + * possibility that compaction would migrate pages from non-CMA to CMA + * pageblock. + */ + if (order > PAGE_ALLOC_COSTLY_ORDER && async && + !(alloc_flags & ALLOC_CMA)) { + if (!__zone_watermark_ok(zone, 0, watermark + compact_gap(order), + highest_zoneidx, 0, + zone_page_state(zone, NR_FREE_PAGES))) + return COMPACT_SKIPPED; + } + + if (!compaction_suitable(zone, order, watermark, highest_zoneidx)) return COMPACT_SKIPPED; return COMPACT_CONTINUE; @@ -2550,7 +2572,9 @@ compact_zone(struct compact_control *cc, struct capture_control *capc) if (!is_via_compact_memory(cc->order)) { ret = compaction_suit_allocation_order(cc->zone, cc->order, cc->highest_zoneidx, - cc->alloc_flags); + cc->alloc_flags, + cc->mode == MIGRATE_ASYNC, + !cc->direct_compaction); if (ret != COMPACT_CONTINUE) return ret; } @@ -2841,6 +2865,11 @@ enum compact_result try_to_compact_pages(gfp_t gfp_mask, unsigned int order, ac->highest_zoneidx, ac->nodemask) { enum compact_result status; + if (cpusets_enabled() && + (alloc_flags & ALLOC_CPUSET) && + !__cpuset_zone_allowed(zone, gfp_mask)) + continue; + if (prio > MIN_COMPACT_PRIORITY && compaction_deferred(zone, order)) { rc = max_t(enum compact_result, COMPACT_DEFERRED, rc); @@ -2950,7 +2979,7 @@ static int compact_nodes(void) return 0; } -static int compaction_proactiveness_sysctl_handler(struct ctl_table *table, int write, +static int compaction_proactiveness_sysctl_handler(const struct ctl_table *table, int write, void *buffer, size_t *length, loff_t *ppos) { int rc, nid; @@ -2980,7 +3009,7 @@ static int compaction_proactiveness_sysctl_handler(struct ctl_table *table, int * This is the entry point for compacting all nodes via * /proc/sys/vm/compact_memory */ -static int sysctl_compaction_handler(struct ctl_table *table, int write, +static int sysctl_compaction_handler(const struct ctl_table *table, int write, void *buffer, size_t *length, loff_t *ppos) { int ret; @@ -3039,6 +3068,8 @@ static bool kcompactd_node_suitable(pg_data_t *pgdat) struct zone *zone; enum zone_type highest_zoneidx = pgdat->kcompactd_highest_zoneidx; enum compact_result ret; + unsigned int alloc_flags = defrag_mode ? + ALLOC_WMARK_HIGH : ALLOC_WMARK_MIN; for (zoneid = 0; zoneid <= highest_zoneidx; zoneid++) { zone = &pgdat->node_zones[zoneid]; @@ -3048,7 +3079,8 @@ static bool kcompactd_node_suitable(pg_data_t *pgdat) ret = compaction_suit_allocation_order(zone, pgdat->kcompactd_max_order, - highest_zoneidx, ALLOC_WMARK_MIN); + highest_zoneidx, alloc_flags, + false, true); if (ret == COMPACT_CONTINUE) return true; } @@ -3071,6 +3103,7 @@ static void kcompactd_do_work(pg_data_t *pgdat) .mode = MIGRATE_SYNC_LIGHT, .ignore_skip_hint = false, .gfp_mask = GFP_KERNEL, + .alloc_flags = defrag_mode ? ALLOC_WMARK_HIGH : ALLOC_WMARK_MIN, }; enum compact_result ret; @@ -3089,7 +3122,8 @@ static void kcompactd_do_work(pg_data_t *pgdat) continue; ret = compaction_suit_allocation_order(zone, - cc.order, zoneid, ALLOC_WMARK_MIN); + cc.order, zoneid, cc.alloc_flags, + false, true); if (ret != COMPACT_CONTINUE) continue; @@ -3167,15 +3201,10 @@ void wakeup_kcompactd(pg_data_t *pgdat, int order, int highest_zoneidx) static int kcompactd(void *p) { pg_data_t *pgdat = (pg_data_t *)p; - struct task_struct *tsk = current; long default_timeout = msecs_to_jiffies(HPAGE_FRAG_CHECK_INTERVAL_MSEC); long timeout = default_timeout; - const struct cpumask *cpumask = cpumask_of_node(pgdat->node_id); - - if (!cpumask_empty(cpumask)) - set_cpus_allowed_ptr(tsk, cpumask); - + current->flags |= PF_KCOMPACTD; set_freezable(); pgdat->kcompactd_max_order = 0; @@ -3232,6 +3261,8 @@ static int kcompactd(void *p) pgdat->proactive_compact_trigger = false; } + current->flags &= ~PF_KCOMPACTD; + return 0; } @@ -3246,10 +3277,12 @@ void __meminit kcompactd_run(int nid) if (pgdat->kcompactd) return; - pgdat->kcompactd = kthread_run(kcompactd, pgdat, "kcompactd%d", nid); + pgdat->kcompactd = kthread_create_on_node(kcompactd, pgdat, nid, "kcompactd%d", nid); if (IS_ERR(pgdat->kcompactd)) { pr_err("Failed to start kcompactd on node %d\n", nid); pgdat->kcompactd = NULL; + } else { + wake_up_process(pgdat->kcompactd); } } @@ -3267,31 +3300,7 @@ void __meminit kcompactd_stop(int nid) } } -/* - * It's optimal to keep kcompactd on the same CPUs as their memory, but - * not required for correctness. So if the last cpu in a node goes - * away, we get changed to run anywhere: as the first one comes back, - * restore their cpu bindings. - */ -static int kcompactd_cpu_online(unsigned int cpu) -{ - int nid; - - for_each_node_state(nid, N_MEMORY) { - pg_data_t *pgdat = NODE_DATA(nid); - const struct cpumask *mask; - - mask = cpumask_of_node(pgdat->node_id); - - if (cpumask_any_and(cpu_online_mask, mask) < nr_cpu_ids) - /* One of our CPUs online: restore mask */ - if (pgdat->kcompactd) - set_cpus_allowed_ptr(pgdat->kcompactd, mask); - } - return 0; -} - -static int proc_dointvec_minmax_warn_RT_change(struct ctl_table *table, +static int proc_dointvec_minmax_warn_RT_change(const struct ctl_table *table, int write, void *buffer, size_t *lenp, loff_t *ppos) { int ret, old; @@ -3310,7 +3319,7 @@ static int proc_dointvec_minmax_warn_RT_change(struct ctl_table *table, return ret; } -static struct ctl_table vm_compaction[] = { +static const struct ctl_table vm_compaction[] = { { .procname = "compact_memory", .data = &sysctl_compact_memory, @@ -3345,21 +3354,11 @@ static struct ctl_table vm_compaction[] = { .extra1 = SYSCTL_ZERO, .extra2 = SYSCTL_ONE, }, - { } }; static int __init kcompactd_init(void) { int nid; - int ret; - - ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, - "mm/compaction:online", - kcompactd_cpu_online, NULL); - if (ret < 0) { - pr_err("kcompactd: failed to register hotplug callbacks.\n"); - return ret; - } for_each_node_state(nid, N_MEMORY) kcompactd_run(nid); |