kernel.git/mm/page_isolation.c, branch linux-3.12.y

mm: fix invalid node in alloc_migrate_target()

2016-04-20T06:40:09Z

commit 6f25a14a7053b69917e2ebea0d31dd444cd31fd5 upstream. It is incorrect to use next_node to find a target node, it will return MAX_NUMNODES or invalid node. This will lead to crash in buddy system allocation. Fixes: c8721bbbdd36 ("mm: memory-hotplug: enable memory hotplug to handle hugepage") Signed-off-by: Xishi Qiu Acked-by: Vlastimil Babka Acked-by: Naoya Horiguchi Cc: Joonsoo Kim Cc: David Rientjes Cc: "Laura Abbott" Cc: Hui Zhu Cc: Wang Xiaoqiang Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Jiri Slaby

mm: memory-hotplug: enable memory hotplug to handle hugepage

2013-09-11T22:57:48Z

Until now we can't offline memory blocks which contain hugepages because a hugepage is considered as an unmovable page. But now with this patch series, a hugepage has become movable, so by using hugepage migration we can offline such memory blocks. What's different from other users of hugepage migration is that we need to decompose all the hugepages inside the target memory block into free buddy pages after hugepage migration, because otherwise free hugepages remaining in the memory block intervene the memory offlining. For this reason we introduce new functions dissolve_free_huge_page() and dissolve_free_huge_pages(). Other than that, what this patch does is straightforwardly to add hugepage migration code, that is, adding hugepage code to the functions which scan over pfn and collect hugepages to be migrated, and adding a hugepage allocation function to alloc_migrate_target(). As for larger hugepages (1GB for x86_64), it's not easy to do hotremove over them because it's larger than memory block. So we now simply leave it to fail as it is. [yongjun_wei@trendmicro.com.cn: remove duplicated include] Signed-off-by: Naoya Horiguchi Acked-by: Andi Kleen Cc: Hillf Danton Cc: Wanpeng Li Cc: Mel Gorman Cc: Hugh Dickins Cc: KOSAKI Motohiro Cc: Michal Hocko Cc: Rik van Riel Cc: "Aneesh Kumar K.V" Signed-off-by: Wei Yongjun Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

page_isolation: Fix a comment typo in test_pages_isolated()

2013-08-20T11:03:41Z

pageblock_nr_page should be pageblock_nr_pages, and fist is a typo of first. Signed-off-by: Tang Chen Signed-off-by: Jiri Kosina

mm: fix zone_watermark_ok_safe() accounting of isolated pages

2013-01-05T00:11:46Z

Commit 702d1a6e0766 ("memory-hotplug: fix kswapd looping forever problem") added an isolated pageblocks counter (nr_pageblock_isolate in struct zone) and used it to adjust free pages counter in zone_watermark_ok_safe() to prevent kswapd looping forever problem. Then later, commit 2139cbe627b8 ("cma: fix counting of isolated pages") fixed accounting of isolated pages in global free pages counter. It made the previous zone_watermark_ok_safe() fix unnecessary and potentially harmful (cause now isolated pages may be accounted twice making free pages counter incorrect). This patch removes the special isolated pageblocks counter altogether which fixes zone_watermark_ok_safe() free pages check. Reported-by: Tomasz Stanislawski Signed-off-by: Bartlomiej Zolnierkiewicz Signed-off-by: Kyungmin Park Cc: Minchan Kim Cc: KOSAKI Motohiro Cc: Aaditya Kumar Cc: KAMEZAWA Hiroyuki Cc: Mel Gorman Cc: Michal Hocko Cc: Marek Szyprowski Cc: Michal Nazarewicz Cc: Hugh Dickins Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

memory-hotplug: skip HWPoisoned page when offlining pages

2012-12-12T01:22:22Z

hwpoisoned may be set when we offline a page by the sysfs interface /sys/devices/system/memory/soft_offline_page or /sys/devices/system/memory/hard_offline_page. If we don't clear this flag when onlining pages, this page can't be freed, and will not in free list. So we can't offline these pages again. So we should skip such page when offlining pages. Signed-off-by: Wen Congyang Cc: David Rientjes Cc: Jiang Liu Cc: Len Brown Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Christoph Lameter Cc: Minchan Kim Cc: KOSAKI Motohiro Cc: Yasuaki Ishimatsu Cc: Andi Kleen Cc: Mel Gorman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm/page_alloc: refactor out __alloc_contig_migrate_alloc()

2012-10-09T07:22:52Z

__alloc_contig_migrate_alloc() can be used by memory-hotplug so refactor it out (move + rename as a common name) into page_isolation.c. [akpm@linux-foundation.org: checkpatch fixes] Signed-off-by: Minchan Kim Cc: Kamezawa Hiroyuki Reviewed-by: Yasuaki Ishimatsu Acked-by: Michal Nazarewicz Cc: Marek Szyprowski Cc: Wen Congyang Acked-by: David Rientjes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

memory-hotplug: fix pages missed by race rather than failing

2012-10-09T07:22:46Z

If race between allocation and isolation in memory-hotplug offline happens, some pages could be in MIGRATE_MOVABLE of free_list although the pageblock's migratetype of the page is MIGRATE_ISOLATE. The race could be detected by get_freepage_migratetype in __test_page_isolated_in_pageblock. If it is detected, now EBUSY gets bubbled all the way up and the hotplug operations fails. But better idea is instead of returning and failing memory-hotremove, move the free page to the correct list at the time it is detected. It could enhance memory-hotremove operation success ratio although the race is really rare. Suggested by Mel Gorman. [akpm@linux-foundation.org: small cleanup] Signed-off-by: Minchan Kim Cc: KAMEZAWA Hiroyuki Reviewed-by: Yasuaki Ishimatsu Acked-by: Mel Gorman Cc: Xishi Qiu Cc: Wen Congyang Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

memory-hotplug: bug fix race between isolation and allocation

2012-10-09T07:22:46Z

Like below, memory-hotplug makes race between page-isolation and page-allocation so it can hit BUG_ON in __offline_isolated_pages. CPU A CPU B start_isolate_page_range set_migratetype_isolate spin_lock_irqsave(zone->lock) free_hot_cold_page(Page A) /* without zone->lock */ migratetype = get_pageblock_migratetype(Page A); /* * Page could be moved into MIGRATE_MOVABLE * of per_cpu_pages */ list_add_tail(&page->lru, &pcp->lists[migratetype]); set_pageblock_isolate move_freepages_block drain_all_pages /* Page A could be in MIGRATE_MOVABLE of free_list. */ check_pages_isolated __test_page_isolated_in_pageblock /* * We can't catch freed page which * is free_list[MIGRATE_MOVABLE] */ if (PageBuddy(page A)) pfn += 1 << page_order(page A); /* So, Page A could be allocated */ __offline_isolated_pages /* * BUG_ON hit or offline page * which is used by someone */ BUG_ON(!PageBuddy(page A)); This patch checks page's migratetype in freelist in __test_page_isolated_in_pageblock. So now __test_page_isolated_in_pageblock can check the page caused by above race and can fail of memory offlining. Signed-off-by: Minchan Kim Acked-by: KAMEZAWA Hiroyuki Reviewed-by: Yasuaki Ishimatsu Acked-by: Mel Gorman Cc: Xishi Qiu Cc: Wen Congyang Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: page_alloc: use get_freepage_migratetype() instead of page_private()

2012-10-09T07:22:45Z

The page allocator uses set_page_private and page_private for handling migratetype when it frees page. Let's replace them with [set|get] _freepage_migratetype to make it more clear. Signed-off-by: Minchan Kim Acked-by: KAMEZAWA Hiroyuki Reviewed-by: Yasuaki Ishimatsu Acked-by: Mel Gorman Cc: Xishi Qiu Cc: Wen Congyang Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

cma: count free CMA pages

2012-10-09T07:22:44Z

Add NR_FREE_CMA_PAGES counter to be later used for checking watermark in __zone_watermark_ok(). For simplicity and to avoid #ifdef hell make this counter always available (not only when CONFIG_CMA=y). [akpm@linux-foundation.org: use conventional migratetype naming] Signed-off-by: Bartlomiej Zolnierkiewicz Signed-off-by: Kyungmin Park Cc: Marek Szyprowski Cc: Michal Nazarewicz Cc: Minchan Kim Cc: Mel Gorman Cc: Hugh Dickins Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds