diff options
| -rw-r--r-- | include/linux/compaction.h | 13 | ||||
| -rw-r--r-- | mm/compaction.c | 72 | ||||
| -rw-r--r-- | mm/internal.h | 5 | ||||
| -rw-r--r-- | mm/page_alloc.c | 28 |
4 files changed, 17 insertions, 101 deletions
diff --git a/include/linux/compaction.h b/include/linux/compaction.h index 0980a6c..d4e106b 100644 --- a/include/linux/compaction.h +++ b/include/linux/compaction.h @@ -55,14 +55,6 @@ enum compact_result { COMPACT_PARTIAL, }; -/* Used to signal whether compaction detected need_sched() or lock contention */ -/* No contention detected */ -#define COMPACT_CONTENDED_NONE 0 -/* Either need_sched() was true or fatal signal pending */ -#define COMPACT_CONTENDED_SCHED 1 -/* Zone lock or lru_lock was contended in async compaction */ -#define COMPACT_CONTENDED_LOCK 2 - struct alloc_context; /* in mm/internal.h */ #ifdef CONFIG_COMPACTION @@ -76,9 +68,8 @@ extern int sysctl_compact_unevictable_allowed; extern int fragmentation_index(struct zone *zone, unsigned int order); extern enum compact_result try_to_compact_pages(gfp_t gfp_mask, - unsigned int order, - unsigned int alloc_flags, const struct alloc_context *ac, - enum compact_priority prio, int *contended); + unsigned int order, unsigned int alloc_flags, + const struct alloc_context *ac, enum compact_priority prio); extern void compact_pgdat(pg_data_t *pgdat, int order); extern void reset_isolation_suitable(pg_data_t *pgdat); extern enum compact_result compaction_suitable(struct zone *zone, int order, diff --git a/mm/compaction.c b/mm/compaction.c index 4719a39..9affb29 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -331,7 +331,7 @@ static bool compact_trylock_irqsave(spinlock_t *lock, unsigned long *flags, { if (cc->mode == MIGRATE_ASYNC) { if (!spin_trylock_irqsave(lock, *flags)) { - cc->contended = COMPACT_CONTENDED_LOCK; + cc->contended = true; return false; } } else { @@ -365,13 +365,13 @@ static bool compact_unlock_should_abort(spinlock_t *lock, } if (fatal_signal_pending(current)) { - cc->contended = COMPACT_CONTENDED_SCHED; + cc->contended = true; return true; } if (need_resched()) { if (cc->mode == MIGRATE_ASYNC) { - cc->contended = COMPACT_CONTENDED_SCHED; + cc->contended = true; return true; } cond_resched(); @@ -394,7 +394,7 @@ static inline bool compact_should_abort(struct compact_control *cc) /* async compaction aborts if contended */ if (need_resched()) { if (cc->mode == MIGRATE_ASYNC) { - cc->contended = COMPACT_CONTENDED_SCHED; + cc->contended = true; return true; } @@ -1619,14 +1619,11 @@ out: trace_mm_compaction_end(start_pfn, cc->migrate_pfn, cc->free_pfn, end_pfn, sync, ret); - if (ret == COMPACT_CONTENDED) - ret = COMPACT_PARTIAL; - return ret; } static enum compact_result compact_zone_order(struct zone *zone, int order, - gfp_t gfp_mask, enum compact_priority prio, int *contended, + gfp_t gfp_mask, enum compact_priority prio, unsigned int alloc_flags, int classzone_idx) { enum compact_result ret; @@ -1650,7 +1647,6 @@ static enum compact_result compact_zone_order(struct zone *zone, int order, VM_BUG_ON(!list_empty(&cc.freepages)); VM_BUG_ON(!list_empty(&cc.migratepages)); - *contended = cc.contended; return ret; } @@ -1663,23 +1659,18 @@ int sysctl_extfrag_threshold = 500; * @alloc_flags: The allocation flags of the current allocation * @ac: The context of current allocation * @mode: The migration mode for async, sync light, or sync migration - * @contended: Return value that determines if compaction was aborted due to - * need_resched() or lock contention * * This is the main entry point for direct page compaction. */ enum compact_result try_to_compact_pages(gfp_t gfp_mask, unsigned int order, unsigned int alloc_flags, const struct alloc_context *ac, - enum compact_priority prio, int *contended) + enum compact_priority prio) { int may_enter_fs = gfp_mask & __GFP_FS; int may_perform_io = gfp_mask & __GFP_IO; struct zoneref *z; struct zone *zone; enum compact_result rc = COMPACT_SKIPPED; - int all_zones_contended = COMPACT_CONTENDED_LOCK; /* init for &= op */ - - *contended = COMPACT_CONTENDED_NONE; /* Check if the GFP flags allow compaction */ if (!may_enter_fs || !may_perform_io) @@ -1691,7 +1682,6 @@ enum compact_result try_to_compact_pages(gfp_t gfp_mask, unsigned int order, for_each_zone_zonelist_nodemask(zone, z, ac->zonelist, ac->high_zoneidx, ac->nodemask) { enum compact_result status; - int zone_contended; if (compaction_deferred(zone, order)) { rc = max_t(enum compact_result, COMPACT_DEFERRED, rc); @@ -1699,14 +1689,8 @@ enum compact_result try_to_compact_pages(gfp_t gfp_mask, unsigned int order, } status = compact_zone_order(zone, order, gfp_mask, prio, - &zone_contended, alloc_flags, - ac_classzone_idx(ac)); + alloc_flags, ac_classzone_idx(ac)); rc = max(status, rc); - /* - * It takes at least one zone that wasn't lock contended - * to clear all_zones_contended. - */ - all_zones_contended &= zone_contended; /* If a normal allocation would succeed, stop compacting */ if (zone_watermark_ok(zone, order, low_wmark_pages(zone), @@ -1718,59 +1702,29 @@ enum compact_result try_to_compact_pages(gfp_t gfp_mask, unsigned int order, * succeeds in this zone. */ compaction_defer_reset(zone, order, false); - /* - * It is possible that async compaction aborted due to - * need_resched() and the watermarks were ok thanks to - * somebody else freeing memory. The allocation can - * however still fail so we better signal the - * need_resched() contention anyway (this will not - * prevent the allocation attempt). - */ - if (zone_contended == COMPACT_CONTENDED_SCHED) - *contended = COMPACT_CONTENDED_SCHED; - goto break_loop; + break; } if (prio != COMPACT_PRIO_ASYNC && (status == COMPACT_COMPLETE || - status == COMPACT_PARTIAL_SKIPPED)) { + status == COMPACT_PARTIAL_SKIPPED)) /* * We think that allocation won't succeed in this zone * so we defer compaction there. If it ends up * succeeding after all, it will be reset. */ defer_compaction(zone, order); - } /* * We might have stopped compacting due to need_resched() in * async compaction, or due to a fatal signal detected. In that - * case do not try further zones and signal need_resched() - * contention. - */ - if ((zone_contended == COMPACT_CONTENDED_SCHED) - || fatal_signal_pending(current)) { - *contended = COMPACT_CONTENDED_SCHED; - goto break_loop; - } - - continue; -break_loop: - /* - * We might not have tried all the zones, so be conservative - * and assume they are not all lock contended. + * case do not try further zones */ - all_zones_contended = 0; - break; + if ((prio == COMPACT_PRIO_ASYNC && need_resched()) + || fatal_signal_pending(current)) + break; } - /* - * If at least one zone wasn't deferred or skipped, we report if all - * zones that were tried were lock contended. - */ - if (rc > COMPACT_INACTIVE && all_zones_contended) - *contended = COMPACT_CONTENDED_LOCK; - return rc; } diff --git a/mm/internal.h b/mm/internal.h index 28932cd..1501304 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -185,10 +185,7 @@ struct compact_control { const unsigned int alloc_flags; /* alloc flags of a direct compactor */ const int classzone_idx; /* zone index of a direct compactor */ struct zone *zone; - int contended; /* Signal need_sched() or lock - * contention detected during - * compaction - */ + bool contended; /* Signal lock or sched contention */ }; unsigned long diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 26c6fe7..ea759b9 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -3099,14 +3099,13 @@ __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order, enum compact_priority prio, enum compact_result *compact_result) { struct page *page; - int contended_compaction; if (!order) return NULL; current->flags |= PF_MEMALLOC; *compact_result = try_to_compact_pages(gfp_mask, order, alloc_flags, ac, - prio, &contended_compaction); + prio); current->flags &= ~PF_MEMALLOC; if (*compact_result <= COMPACT_INACTIVE) @@ -3135,24 +3134,6 @@ __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order, */ count_vm_event(COMPACTFAIL); - /* - * In all zones where compaction was attempted (and not - * deferred or skipped), lock contention has been detected. - * For THP allocation we do not want to disrupt the others - * so we fallback to base pages instead. - */ - if (contended_compaction == COMPACT_CONTENDED_LOCK) - *compact_result = COMPACT_CONTENDED; - - /* - * If compaction was aborted due to need_resched(), we do not - * want to further increase allocation latency, unless it is - * khugepaged trying to collapse. - */ - if (contended_compaction == COMPACT_CONTENDED_SCHED - && !(current->flags & PF_KTHREAD)) - *compact_result = COMPACT_CONTENDED; - cond_resched(); return NULL; @@ -3548,13 +3529,6 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order, goto nopage; /* - * Compaction is contended so rather back off than cause - * excessive stalls. - */ - if (compact_result == COMPACT_CONTENDED) - goto nopage; - - /* * Looks like reclaim/compaction is worth trying, but * sync compaction could be very expensive, so keep * using async compaction. |