The patch titled
Subject: mm: vmscan: fix endless loop in kswapd balancing
has been added to the -mm tree. Its filename is
mm-vmscan-fix-endless-loop-in-kswapd-balancing.patch
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------------------------------------------------------
From: Johannes Weiner <hannes@xxxxxxxxxxx>
Subject: mm: vmscan: fix endless loop in kswapd balancing
Kswapd does not in all places have the same criteria for when it considers
a zone balanced. This leads to zones being not reclaimed because they are
considered just fine and the compaction checks to loop over the zonelist
again because they are considered unbalanced, causing kswapd to run
forever.
Add a function, zone_balanced(), that checks the watermark and if
compaction has enough free memory to do its job. Then use it uniformly
for when kswapd needs to check if a zone is balanced.
Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx>
Tested-by: Johannes Hirte <johannes.hirte@xxxxxxxxxxxxxxxxx>
Reviewed-by: Rik van Riel <riel@xxxxxxxxxx>
Cc: Mel Gorman <mel@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/vmscan.c | 27 ++++++++++++++++++---------
1 file changed, 18 insertions(+), 9 deletions(-)
diff -puN mm/vmscan.c~mm-vmscan-fix-endless-loop-in-kswapd-balancing mm/vmscan.c
--- a/mm/vmscan.c~mm-vmscan-fix-endless-loop-in-kswapd-balancing
+++ a/mm/vmscan.c
@@ -2414,6 +2414,19 @@ static void age_active_anon(struct zone
} 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
@@ -2492,8 +2505,7 @@ static bool prepare_kswapd_sleep(pg_data
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;
@@ -2602,8 +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 {
@@ -2679,9 +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;
@@ -2708,8 +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
_
Patches currently in -mm which might be from hannes@xxxxxxxxxxx are
mm-vmemmap-fix-wrong-use-of-virt_to_page.patch
mm-vmscan-fix-endless-loop-in-kswapd-balancing.patch
linux-next.patch
mm-slab-remove-duplicate-check.patch
mmvmscan-only-evict-file-pages-when-we-have-plenty.patch
mmvmscan-only-evict-file-pages-when-we-have-plenty-fix.patch
mm-refactor-reinsert-of-swap_info-in-sys_swapoff.patch
mm-do-not-call-frontswap_init-during-swapoff.patch
mm-thp-set-the-accessed-flag-for-old-pages-on-access-fault.patch
mm-memmap_init_zone-performance-improvement.patch
memcg-make-it-possible-to-use-the-stock-for-more-than-one-page.patch
memcg-reclaim-when-more-than-one-page-needed.patch
memcg-change-defines-to-an-enum.patch
memcg-kmem-accounting-basic-infrastructure.patch
mm-add-a-__gfp_kmemcg-flag.patch
memcg-kmem-controller-infrastructure.patch
memcg-kmem-controller-infrastructure-replace-__always_inline-with-plain-inline.patch
mm-allocate-kernel-pages-to-the-right-memcg.patch
res_counter-return-amount-of-charges-after-res_counter_uncharge.patch
memcg-kmem-accounting-lifecycle-management.patch
memcg-use-static-branches-when-code-not-in-use.patch
memcg-allow-a-memcg-with-kmem-charges-to-be-destructed.patch
memcg-execute-the-whole-memcg-freeing-in-free_worker.patch
fork-protect-architectures-where-thread_size-=-page_size-against-fork-bombs.patch
memcg-add-documentation-about-the-kmem-controller.patch
slab-slub-struct-memcg_params.patch
slab-annotate-on-slab-caches-nodelist-locks.patch
slab-slub-consider-a-memcg-parameter-in-kmem_create_cache.patch
memcg-allocate-memory-for-memcg-caches-whenever-a-new-memcg-appears.patch
memcg-allocate-memory-for-memcg-caches-whenever-a-new-memcg-appears-simplify-ida-initialization.patch
memcg-infrastructure-to-match-an-allocation-to-the-right-cache.patch
memcg-skip-memcg-kmem-allocations-in-specified-code-regions.patch
memcg-skip-memcg-kmem-allocations-in-specified-code-regions-remove-test-for-current-mm-in-memcg_stop-resume_kmem_account.patch
slb-always-get-the-cache-from-its-page-in-kmem_cache_free.patch
slb-allocate-objects-from-memcg-cache.patch
memcg-destroy-memcg-caches.patch
memcg-destroy-memcg-caches-move-include-of-workqueueh-to-top-of-slabh-file.patch
memcg-slb-track-all-the-memcg-children-of-a-kmem_cache.patch
memcg-slb-shrink-dead-caches.patch
memcg-slb-shrink-dead-caches-get-rid-of-once-per-second-cache-shrinking-for-dead-memcgs.patch
memcg-aggregate-memcg-cache-values-in-slabinfo.patch
slab-propagate-tunable-values.patch
slub-slub-specific-propagation-changes.patch
slub-slub-specific-propagation-changes-fix.patch
kmem-add-slab-specific-documentation-about-the-kmem-controller.patch
memcg-add-comments-clarifying-aspects-of-cache-attribute-propagation.patch
slub-drop-mutex-before-deleting-sysfs-entry.patch
bootmem-remove-not-implemented-function-call-bootmem_arch_preferred_node.patch
avr32-kconfig-remove-have_arch_bootmem.patch
bootmem-remove-alloc_arch_preferred_bootmem.patch
bootmem-fix-wrong-call-parameter-for-free_bootmem.patch
bootmem-fix-wrong-call-parameter-for-free_bootmem-fix.patch
mm-memcg-avoid-unnecessary-function-call-when-memcg-is-disabled.patch
mm-introduce-new-field-managed_pages-to-struct-zone.patch
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