The patch titled Subject: memory-hotplug: fix zone stat mismatch has been added to the -mm tree. Its filename is memory-hotplug-fix-zone-stat-mismatch.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Minchan Kim <minchan@xxxxxxxxxx> Subject: memory-hotplug: fix zone stat mismatch During memory-hotplug, I found NR_ISOLATED_[ANON|FILE] are increasing, causing the kernel to hang. When the system doesn't have enough free pages, it enters reclaim but never reclaim any pages due to too_many_isolated()==true and loops forever. The cause is that when we do memory-hotadd after memory-remove, __zone_pcp_update() clears a zone's ZONE_STAT_ITEMS in setup_pageset() although the vm_stat_diff of all CPUs still have values. In addtion, when we offline all pages of the zone, we reset them in zone_pcp_reset without draining so we loss some zone stat item. Reviewed-by: Wen Congyang <wency@xxxxxxxxxxxxxx> Signed-off-by: Minchan Kim <minchan@xxxxxxxxxx> Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@xxxxxxxxxxxxxx> Cc: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/vmstat.h | 4 ++++ mm/page_alloc.c | 7 +++++++ mm/vmstat.c | 12 ++++++++++++ 3 files changed, 23 insertions(+) diff -puN include/linux/vmstat.h~memory-hotplug-fix-zone-stat-mismatch include/linux/vmstat.h --- a/include/linux/vmstat.h~memory-hotplug-fix-zone-stat-mismatch +++ a/include/linux/vmstat.h @@ -198,6 +198,8 @@ extern void __dec_zone_state(struct zone void refresh_cpu_vm_stats(int); void refresh_zone_stat_thresholds(void); +void drain_zonestat(struct zone *zone, struct per_cpu_pageset *); + int calculate_pressure_threshold(struct zone *zone); int calculate_normal_threshold(struct zone *zone); void set_pgdat_percpu_threshold(pg_data_t *pgdat, @@ -251,6 +253,8 @@ static inline void __dec_zone_page_state static inline void refresh_cpu_vm_stats(int cpu) { } static inline void refresh_zone_stat_thresholds(void) { } +static inline void drain_zonestat(struct zone *zone, + struct per_cpu_pageset *pset) { } #endif /* CONFIG_SMP */ static inline void __mod_zone_freepage_state(struct zone *zone, int nr_pages, diff -puN mm/page_alloc.c~memory-hotplug-fix-zone-stat-mismatch mm/page_alloc.c --- a/mm/page_alloc.c~memory-hotplug-fix-zone-stat-mismatch +++ a/mm/page_alloc.c @@ -5908,6 +5908,7 @@ static int __meminit __zone_pcp_update(v local_irq_save(flags); if (pcp->count > 0) free_pcppages_bulk(zone, pcp->count, pcp); + drain_zonestat(zone, pset); setup_pageset(pset, batch); local_irq_restore(flags); } @@ -5924,10 +5925,16 @@ void __meminit zone_pcp_update(struct zo void zone_pcp_reset(struct zone *zone) { unsigned long flags; + int cpu; + struct per_cpu_pageset *pset; /* avoid races with drain_pages() */ local_irq_save(flags); if (zone->pageset != &boot_pageset) { + for_each_online_cpu(cpu) { + pset = per_cpu_ptr(zone->pageset, cpu); + drain_zonestat(zone, pset); + } free_percpu(zone->pageset); zone->pageset = &boot_pageset; } diff -puN mm/vmstat.c~memory-hotplug-fix-zone-stat-mismatch mm/vmstat.c --- a/mm/vmstat.c~memory-hotplug-fix-zone-stat-mismatch +++ a/mm/vmstat.c @@ -495,6 +495,18 @@ void refresh_cpu_vm_stats(int cpu) atomic_long_add(global_diff[i], &vm_stat[i]); } +void drain_zonestat(struct zone *zone, struct per_cpu_pageset *pset) +{ + int i; + + for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) + if (pset->vm_stat_diff[i]) { + int v = pset->vm_stat_diff[i]; + pset->vm_stat_diff[i] = 0; + atomic_long_add(v, &zone->vm_stat[i]); + atomic_long_add(v, &vm_stat[i]); + } +} #endif #ifdef CONFIG_NUMA _ Patches currently in -mm which might be from minchan@xxxxxxxxxx are origin.patch linux-next.patch mm-remove-__gfp_no_kswapd.patch mm-fix-nonuniform-page-status-when-writing-new-file-with-small-buffer.patch mm-fix-nonuniform-page-status-when-writing-new-file-with-small-buffer-fix.patch mm-fix-nonuniform-page-status-when-writing-new-file-with-small-buffer-fix-fix.patch mm-compaction-update-comment-in-try_to_compact_pages.patch mm-vmscan-scale-number-of-pages-reclaimed-by-reclaim-compaction-based-on-failures.patch mm-vmscan-scale-number-of-pages-reclaimed-by-reclaim-compaction-based-on-failures-fix.patch mm-compaction-capture-a-suitable-high-order-page-immediately-when-it-is-made-available.patch mm-cma-discard-clean-pages-during-contiguous-allocation-instead-of-migration.patch mm-cma-discard-clean-pages-during-contiguous-allocation-instead-of-migration-fix.patch mm-cma-discard-clean-pages-during-contiguous-allocation-instead-of-migration-fix-fix.patch mm-fix-tracing-in-free_pcppages_bulk.patch mm-fix-tracing-in-free_pcppages_bulk-fix.patch cma-fix-counting-of-isolated-pages.patch cma-count-free-cma-pages.patch cma-count-free-cma-pages-fix.patch cma-fix-watermark-checking.patch mm-page_alloc-use-get_freepage_migratetype-instead-of-page_private.patch mm-remain-migratetype-in-freed-page.patch memory-hotplug-bug-fix-race-between-isolation-and-allocation.patch memory-hotplug-fix-pages-missed-by-race-rather-than-failing.patch memory-hotplug-fix-pages-missed-by-race-rather-than-failng-fix.patch swap-add-a-simple-detector-for-inappropriate-swapin-readahead.patch swap-add-a-simple-detector-for-inappropriate-swapin-readahead-fix.patch mm-memblock-reduce-overhead-in-binary-search.patch mm-memblock-use-existing-interface-to-set-nid.patch mm-memblock-cleanup-early_node_map-related-comments.patch mm-compaction-abort-compaction-loop-if-lock-is-contended-or-run-too-long.patch mm-compaction-abort-compaction-loop-if-lock-is-contended-or-run-too-long-fix.patch mm-compaction-abort-compaction-loop-if-lock-is-contended-or-run-too-long-fix-2.patch mm-compaction-check-lock-contention-first-before-taking-lock.patch mm-page_alloc-refactor-out-__alloc_contig_migrate_alloc.patch mm-page_alloc-refactor-out-__alloc_contig_migrate_alloc-checkpatch-fixes.patch memory-hotplug-dont-replace-lowmem-pages-with-highmem.patch mm-compaction-move-fatal-signal-check-out-of-compact_checklock_irqsave.patch mm-enable-config_compaction-by-default.patch mm-numa-reclaim-from-all-nodes-within-reclaim-distance.patch mm-numa-reclaim-from-all-nodes-within-reclaim-distance-fix.patch mm-revert-0def08e3-mm-mempolicyc-check-return-code-of-check_range.patch trace-events-kmem-dont-call-page_to_pfn-if-page-is-null.patch memory-hotplug-fix-zone-stat-mismatch.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