The patch titled
mm-page-allocator-adjust-the-per-cpu-counter-threshold-when-memory-is-low-update
has been removed from the -mm tree. Its filename was
mm-vmstat-use-a-single-setter-function-and-callback-for-adjusting-percpu-thresholds-update.patch
This patch was dropped because it was folded into mm-vmstat-use-a-single-setter-function-and-callback-for-adjusting-percpu-thresholds.patch
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: mm-page-allocator-adjust-the-per-cpu-counter-threshold-when-memory-is-low-update
From: Mel Gorman <mel@xxxxxxxxx>
mm: vmscan: Comment on why kswapd reduces the per-cpu vmstat threshold
While kswapd is awake, the per-cpu vmstat threshold is reduced to
reduce per-cpu drift to acceptable levels. Add a comment explaining
why.
Signed-off-by: Mel Gorman <mel@xxxxxxxxx>
Cc: Christoph Lameter <cl@xxxxxxxxx>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Cc: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/vmscan.c | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff -puN mm/vmscan.c~mm-vmstat-use-a-single-setter-function-and-callback-for-adjusting-percpu-thresholds-update mm/vmscan.c
--- a/mm/vmscan.c~mm-vmstat-use-a-single-setter-function-and-callback-for-adjusting-percpu-thresholds-update
+++ a/mm/vmscan.c
@@ -2448,6 +2448,19 @@ static int kswapd(void *p)
*/
if (!sleeping_prematurely(pgdat, order, remaining)) {
trace_mm_vmscan_kswapd_sleep(pgdat->node_id);
+
+ /*
+ * vmstat counters are not perfectly
+ * accurate and the estimated value
+ * for counters such as NR_FREE_PAGES
+ * can deviate from the true value by
+ * nr_online_cpus * threshold. To
+ * avoid the zone watermarks being
+ * breached while under pressure, we
+ * reduce the per-cpu vmstat threshold
+ * while kswapd is awake and restore
+ * them before going back to sleep.
+ */
set_pgdat_percpu_threshold(pgdat,
calculate_normal_threshold);
schedule();
_
Patches currently in -mm which might be from mel@xxxxxxxxx are
mm-page-allocator-adjust-the-per-cpu-counter-threshold-when-memory-is-low.patch
mm-vmstat-use-a-single-setter-function-and-callback-for-adjusting-percpu-thresholds.patch
mm-vmstat-use-a-single-setter-function-and-callback-for-adjusting-percpu-thresholds-fix-set_pgdat_percpu_threshold-dont-use-for_each_online_cpu.patch
vmscan-factor-out-kswapd-sleeping-logic-from-kswapd.patch
mm-compaction-add-trace-events-for-memory-compaction-activity.patch
mm-vmscan-convert-lumpy_mode-into-a-bitmask.patch
mm-vmscan-reclaim-order-0-and-use-compaction-instead-of-lumpy-reclaim.patch
mm-vmscan-reclaim-order-0-and-use-compaction-instead-of-lumpy-reclaim-fix.patch
mm-vmscan-reclaim-order-0-and-use-compaction-instead-of-lumpy-reclaim-avoid-a-potential-deadlock-due-to-lock_page-during-direct-compaction.patch
mm-vmscan-reclaim-order-0-and-use-compaction-instead-of-lumpy-reclaim-avoid-a-potential-deadlock-due-to-lock_page-during-direct-compaction-fix.patch
mm-migration-allow-migration-to-operate-asynchronously-and-avoid-synchronous-compaction-in-the-faster-path.patch
mm-migration-allow-migration-to-operate-asynchronously-and-avoid-synchronous-compaction-in-the-faster-path-fix.patch
mm-migration-cleanup-migrate_pages-api-by-matching-types-for-offlining-and-sync.patch
mm-compaction-perform-a-faster-migration-scan-when-migrating-asynchronously.patch
mm-vmscan-rename-lumpy_mode-to-reclaim_mode.patch
mm-vmscan-rename-lumpy_mode-to-reclaim_mode-fix.patch
mm-kswapd-stop-high-order-balancing-when-any-suitable-zone-is-balanced.patch
mm-kswapd-keep-kswapd-awake-for-high-order-allocations-until-a-percentage-of-the-node-is-balanced.patch
mm-kswapd-use-the-order-that-kswapd-was-reclaiming-at-for-sleeping_prematurely.patch
mm-kswapd-reset-kswapd_max_order-and-classzone_idx-after-reading.patch
mm-kswapd-treat-zone-all_unreclaimable-in-sleeping_prematurely-similar-to-balance_pgdat.patch
mm-kswapd-use-the-classzone-idx-that-kswapd-was-using-for-sleeping_prematurely.patch
thp-fix-bad_page-to-show-the-real-reason-the-page-is-bad.patch
thp-mm-define-madv_hugepage.patch
thp-alter-compound-get_page-put_page.patch
thp-update-futex-compound-knowledge.patch
thp-clear-compound-mapping.patch
thp-add-native_set_pmd_at.patch
thp-add-pmd-paravirt-ops.patch
thp-no-paravirt-version-of-pmd-ops.patch
thp-export-maybe_mkwrite.patch
thp-comment-reminder-in-destroy_compound_page.patch
thp-config_transparent_hugepage.patch
thp-config_transparent_hugepage-fix.patch
thp-special-pmd_trans_-functions.patch
thp-add-pmd-mangling-generic-functions.patch
thp-add-pmd-mangling-generic-functions-fix-pgtableh-build-for-um.patch
thp-bail-out-gup_fast-on-splitting-pmd.patch
thp-pte-alloc-trans-splitting.patch
thp-pte-alloc-trans-splitting-fix.patch
thp-clear-page-compound.patch
thp-add-pmd_huge_pte-to-mm_struct.patch
thp-split_huge_page_mm-vma.patch
thp-split_huge_page-paging.patch
thp-clear_copy_huge_page.patch
thp-_gfp_no_kswapd.patch
thp-dont-alloc-harder-for-gfp-nomemalloc-even-if-nowait.patch
thp-split_huge_page-anon_vma-ordering-dependency.patch
thp-verify-pmd_trans_huge-isnt-leaking.patch
thp-skip-transhuge-pages-in-ksm-for-now.patch
thp-enable-direct-defrag.patch
thp-select-config_compaction-if-transparent_hugepage-enabled.patch
thp-transhuge-isolate_migratepages.patch
thp-disable-transparent-hugepages-by-default-on-small-systems.patch
mm-migration-use-rcu_dereference_protected-when-dereferencing-the-radix-tree-slot-during-file-page-migration.patch
mm-migration-use-rcu_dereference_protected-when-dereferencing-the-radix-tree-slot-during-file-page-migration-fix.patch
mm-fix-migration-hangs-on-anon_vma-lock.patch
mm-fix-hugepage-migration.patch
mm-page_allocc-dont-cache-current-in-a-local.patch
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