diff options
Diffstat (limited to 'mm/vmscan.c')
| -rw-r--r-- | mm/vmscan.c | 83 |
1 files changed, 45 insertions, 38 deletions
diff --git a/mm/vmscan.c b/mm/vmscan.c index 48550c6..b7ed376 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -2207,9 +2207,12 @@ static bool pfmemalloc_watermark_ok(pg_data_t *pgdat) * Throttle direct reclaimers if backing storage is backed by the network * and the PFMEMALLOC reserve for the preferred node is getting dangerously * depleted. kswapd will continue to make progress and wake the processes - * when the low watermark is reached + * when the low watermark is reached. + * + * Returns true if a fatal signal was delivered during throttling. If this + * happens, the page allocator should not consider triggering the OOM killer. */ -static void throttle_direct_reclaim(gfp_t gfp_mask, struct zonelist *zonelist, +static bool throttle_direct_reclaim(gfp_t gfp_mask, struct zonelist *zonelist, nodemask_t *nodemask) { struct zone *zone; @@ -2224,13 +2227,20 @@ static void throttle_direct_reclaim(gfp_t gfp_mask, struct zonelist *zonelist, * processes to block on log_wait_commit(). */ if (current->flags & PF_KTHREAD) - return; + goto out; + + /* + * If a fatal signal is pending, this process should not throttle. + * It should return quickly so it can exit and free its memory + */ + if (fatal_signal_pending(current)) + goto out; /* Check if the pfmemalloc reserves are ok */ first_zones_zonelist(zonelist, high_zoneidx, NULL, &zone); pgdat = zone->zone_pgdat; if (pfmemalloc_watermark_ok(pgdat)) - return; + goto out; /* Account for the throttling */ count_vm_event(PGSCAN_DIRECT_THROTTLE); @@ -2246,12 +2256,20 @@ static void throttle_direct_reclaim(gfp_t gfp_mask, struct zonelist *zonelist, if (!(gfp_mask & __GFP_FS)) { wait_event_interruptible_timeout(pgdat->pfmemalloc_wait, pfmemalloc_watermark_ok(pgdat), HZ); - return; + + goto check_pending; } /* Throttle until kswapd wakes the process */ wait_event_killable(zone->zone_pgdat->pfmemalloc_wait, pfmemalloc_watermark_ok(pgdat)); + +check_pending: + if (fatal_signal_pending(current)) + return true; + +out: + return false; } unsigned long try_to_free_pages(struct zonelist *zonelist, int order, @@ -2273,13 +2291,12 @@ unsigned long try_to_free_pages(struct zonelist *zonelist, int order, .gfp_mask = sc.gfp_mask, }; - throttle_direct_reclaim(gfp_mask, zonelist, nodemask); - /* - * Do not enter reclaim if fatal signal is pending. 1 is returned so - * that the page allocator does not consider triggering OOM + * Do not enter reclaim if fatal signal was delivered while throttled. + * 1 is returned so that the page allocator does not OOM kill at this + * point. */ - if (fatal_signal_pending(current)) + if (throttle_direct_reclaim(gfp_mask, zonelist, nodemask)) return 1; trace_mm_vmscan_direct_reclaim_begin(order, @@ -2397,6 +2414,19 @@ static void age_active_anon(struct zone *zone, struct scan_control *sc) } while (memcg); } +static bool zone_balanced(struct zone *zone, int order, + unsigned long balance_gap, int classzone_idx) +{ + if (!zone_watermark_ok_safe(zone, order, high_wmark_pages(zone) + + balance_gap, classzone_idx, 0)) + return false; + + if (COMPACTION_BUILD && order && !compaction_suitable(zone, order)) + return false; + + return true; +} + /* * pgdat_balanced is used when checking if a node is balanced for high-order * allocations. Only zones that meet watermarks and are in a zone allowed @@ -2475,8 +2505,7 @@ static bool prepare_kswapd_sleep(pg_data_t *pgdat, int order, long remaining, continue; } - if (!zone_watermark_ok_safe(zone, order, high_wmark_pages(zone), - i, 0)) + if (!zone_balanced(zone, order, 0, i)) all_zones_ok = false; else balanced += zone->present_pages; @@ -2585,8 +2614,7 @@ loop_again: break; } - if (!zone_watermark_ok_safe(zone, order, - high_wmark_pages(zone), 0, 0)) { + if (!zone_balanced(zone, order, 0, 0)) { end_zone = i; break; } else { @@ -2662,9 +2690,8 @@ loop_again: testorder = 0; if ((buffer_heads_over_limit && is_highmem_idx(i)) || - !zone_watermark_ok_safe(zone, testorder, - high_wmark_pages(zone) + balance_gap, - end_zone, 0)) { + !zone_balanced(zone, testorder, + balance_gap, end_zone)) { shrink_zone(zone, &sc); reclaim_state->reclaimed_slab = 0; @@ -2691,8 +2718,7 @@ loop_again: continue; } - if (!zone_watermark_ok_safe(zone, testorder, - high_wmark_pages(zone), end_zone, 0)) { + if (!zone_balanced(zone, testorder, 0, end_zone)) { all_zones_ok = 0; /* * We are still under min water mark. This @@ -2797,29 +2823,10 @@ out: if (!populated_zone(zone)) continue; - if (zone->all_unreclaimable && - sc.priority != DEF_PRIORITY) - continue; - - /* Would compaction fail due to lack of free memory? */ - if (COMPACTION_BUILD && - compaction_suitable(zone, order) == COMPACT_SKIPPED) - goto loop_again; - - /* Confirm the zone is balanced for order-0 */ - if (!zone_watermark_ok(zone, 0, - high_wmark_pages(zone), 0, 0)) { - order = sc.order = 0; - goto loop_again; - } - /* Check if the memory needs to be defragmented. */ if (zone_watermark_ok(zone, order, low_wmark_pages(zone), *classzone_idx, 0)) zones_need_compaction = 0; - - /* If balanced, clear the congested flag */ - zone_clear_flag(zone, ZONE_CONGESTED); } if (zones_need_compaction) |