The patch titled Subject: vmstat: do not use deferrable delayed work for vmstat_update has been removed from the -mm tree. Its filename was vmstat-do-not-use-deferrable-delayed-work-for-vmstat_update.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Michal Hocko <mhocko@xxxxxxx> Subject: vmstat: do not use deferrable delayed work for vmstat_update Vinayak Menon has reported that an excessive number of tasks was throttled in the direct reclaim inside too_many_isolated() because NR_ISOLATED_FILE was relatively high compared to NR_INACTIVE_FILE. However it turned out that the real number of NR_ISOLATED_FILE was 0 and the per-cpu vm_stat_diff wasn't transferred into the global counter. vmstat_work which is responsible for the sync is defined as deferrable delayed work which means that the defined timeout doesn't wake up an idle CPU. A CPU might stay in an idle state for a long time and general effort is to keep such a CPU in this state as long as possible which might lead to all sorts of troubles for vmstat consumers as can be seen with the excessive direct reclaim throttling. This patch basically reverts 39bf6270f524 ("VM statistics: Make timer deferrable") but it shouldn't cause any problems for idle CPUs because only CPUs with an active per-cpu drift are woken up since 7cc36bbddde5 ("vmstat: on-demand vmstat workers v8") and CPUs which are idle for a longer time shouldn't have per-cpu drift. Fixes: 39bf6270f524 (VM statistics: Make timer deferrable) Signed-off-by: Michal Hocko <mhocko@xxxxxxx> Reported-by: Vinayak Menon <vinmenon@xxxxxxxxxxxxxx> Acked-by: Christoph Lameter <cl@xxxxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: Vladimir Davydov <vdavydov@xxxxxxxxxxxxx> Cc: Mel Gorman <mgorman@xxxxxxx> Cc: Minchan Kim <minchan@xxxxxxxxxx> Cc: David Rientjes <rientjes@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/vmstat.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff -puN mm/vmstat.c~vmstat-do-not-use-deferrable-delayed-work-for-vmstat_update mm/vmstat.c --- a/mm/vmstat.c~vmstat-do-not-use-deferrable-delayed-work-for-vmstat_update +++ a/mm/vmstat.c @@ -1452,7 +1452,7 @@ static void __init start_shepherd_timer( int cpu; for_each_possible_cpu(cpu) - INIT_DEFERRABLE_WORK(per_cpu_ptr(&vmstat_work, cpu), + INIT_DELAYED_WORK(per_cpu_ptr(&vmstat_work, cpu), vmstat_update); if (!alloc_cpumask_var(&cpu_stat_off, GFP_KERNEL)) _ Patches currently in -mm which might be from mhocko@xxxxxxx are origin.patch list_lru-introduce-list_lru_shrink_countwalk.patch fs-consolidate-nrfree_cached_objects-args-in-shrink_control.patch vmscan-per-memory-cgroup-slab-shrinkers.patch memcg-rename-some-cache-id-related-variables.patch memcg-add-rwsem-to-synchronize-against-memcg_caches-arrays-relocation.patch list_lru-get-rid-of-active_nodes.patch list_lru-organize-all-list_lrus-to-list.patch list_lru-introduce-per-memcg-lists.patch fs-make-shrinker-memcg-aware.patch fs-shrinker-always-scan-at-least-one-object-of-each-type.patch fs-shrinker-always-scan-at-least-one-object-of-each-type-fix.patch mm-vmscan-fix-the-page-state-calculation-in-too_many_isolated.patch slab-embed-memcg_cache_params-to-kmem_cache.patch slab-link-memcg-caches-of-the-same-kind-into-a-list.patch cgroup-release-css-id-after-css_free.patch slab-use-css-id-for-naming-per-memcg-caches.patch memcg-free-memcg_caches-slot-on-css-offline.patch list_lru-add-helpers-to-isolate-items.patch memcg-reparent-list_lrus-and-free-kmemcg_id-on-css-offline.patch memcg-cleanup-static-keys-decrement.patch mm-page_isolation-check-pfn-validity-before-access.patch mm-support-madvisemadv_free.patch mm-dont-split-thp-page-when-syscall-is-called.patch mm-dont-split-thp-page-when-syscall-is-called-fix-2.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html