The patch titled Subject: memory-hotplug: fix NR_FREE_PAGES mismatch has been added to the -mm tree. Its filename is memory-hotplug-fix-nr_free_pages-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: Wen Congyang <wency@xxxxxxxxxxxxxx> Subject: memory-hotplug: fix NR_FREE_PAGES mismatch NR_FREE_PAGES will be wrong after offlining pages. We add/dec NR_FREE_PAGES like this now: 1. move all pages in buddy system to MIGRATE_ISOLATE, and dec NR_FREE_PAGES 2. don't add NR_FREE_PAGES when it is freed and the migratetype is MIGRATE_ISOLATE 3. dec NR_FREE_PAGES when offlining isolated pages. 4. add NR_FREE_PAGES when undoing isolate pages. When we come to step 3, all pages are in MIGRATE_ISOLATE list, and NR_FREE_PAGES are right. When we come to step4, all pages are not in buddy system, so we don't change NR_FREE_PAGES in this step, but we change NR_FREE_PAGES in step3. So NR_FREE_PAGES is wrong after offlining pages. So there is no need to change NR_FREE_PAGES in step3. This patch also fixs a problem in step2: if the migratetype is MIGRATE_ISOLATE, we should not add NR_FRR_PAGES when we remove pages from pcppages. Signed-off-by: Wen Congyang <wency@xxxxxxxxxxxxxx> Cc: David Rientjes <rientjes@xxxxxxxxxx> Cc: Jiang Liu <liuj97@xxxxxxxxx> Cc: Len Brown <len.brown@xxxxxxxxx> Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> Cc: Paul Mackerras <paulus@xxxxxxxxx> Cc: Christoph Lameter <cl@xxxxxxxxx> Cc: Minchan Kim <minchan.kim@xxxxxxxxx> Cc: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@xxxxxxxxxxxxxx> Cc: Dave Hansen <dave@xxxxxxxxxxxxxxxxxx> Cc: Mel Gorman <mel@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/page_alloc.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff -puN mm/page_alloc.c~memory-hotplug-fix-nr_free_pages-mismatch mm/page_alloc.c --- a/mm/page_alloc.c~memory-hotplug-fix-nr_free_pages-mismatch +++ a/mm/page_alloc.c @@ -666,11 +666,13 @@ static void free_pcppages_bulk(struct zo /* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */ __free_one_page(page, zone, 0, mt); trace_mm_page_pcpu_drain(page, 0, mt); - if (is_migrate_cma(mt)) - __mod_zone_page_state(zone, NR_FREE_CMA_PAGES, 1); + if (likely(mt != MIGRATE_ISOLATE)) { + __mod_zone_page_state(zone, NR_FREE_PAGES, 1); + if (is_migrate_cma(mt)) + __mod_zone_page_state(zone, NR_FREE_CMA_PAGES, 1); + } } while (--to_free && --batch_free && !list_empty(list)); } - __mod_zone_page_state(zone, NR_FREE_PAGES, count); spin_unlock(&zone->lock); } @@ -6045,8 +6047,6 @@ __offline_isolated_pages(unsigned long s list_del(&page->lru); rmv_page_order(page); zone->free_area[order].nr_free--; - __mod_zone_page_state(zone, NR_FREE_PAGES, - - (1UL << order)); for (i = 0; i < (1 << order); i++) SetPageReserved((page+i)); pfn += (1 << order); _ Patches currently in -mm which might be from wency@xxxxxxxxxxxxxx are cpu_hotplug-unmap-cpu2node-when-the-cpu-is-hotremoved.patch cpu_hotplug-unmap-cpu2node-when-the-cpu-is-hotremoved-fix.patch acpi_memhotplugc-fix-memory-leak-when-memory-device-is-unbound-from-the-module-acpi_memhotplug.patch acpi_memhotplugc-free-memory-device-if-acpi_memory_enable_device-failed.patch acpi_memhotplugc-remove-memory-info-from-list-before-freeing-it.patch acpi_memhotplugc-dont-allow-to-eject-the-memory-device-if-it-is-being-used.patch acpi_memhotplugc-bind-the-memory-device-when-the-driver-is-being-loaded.patch acpi_memhotplugc-auto-bind-the-memory-device-which-is-hotplugged-before-the-driver-is-loaded.patch x86-numa-dont-check-if-node-is-numa_no_node.patch memory-hotplug-suppress-device-memoryx-does-not-have-a-release-function-warning.patch memory-hotplug-suppress-device-nodex-does-not-have-a-release-function-warning.patch memory-hotplug-skip-hwpoisoned-page-when-offlining-pages.patch memory-hotplug-update-mce_bad_pages-when-removing-the-memory.patch memory-hotplug-update-mce_bad_pages-when-removing-the-memory-fix.patch memory-hotplug-auto-offline-page_cgroup-when-onlining-memory-block-failed.patch memory-hotplug-fix-nr_free_pages-mismatch.patch memory-hotplug-allocate-zones-pcp-before-onlining-pages.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