From: Michal Hocko <mhocko@kernel.org> To: <linux-mm@kvack.org> Cc: Michael Ellerman <mpe@ellerman.id.au>, Vlastimil Babka <vbabka@suse.cz>, Andrew Morton <akpm@linux-foundation.org>, KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>, Reza Arbab <arbab@linux.vnet.ibm.com>, Yasuaki Ishimatsu <yasu.isimatu@gmail.com>, qiuxishi@huawei.com, Igor Mammedov <imammedo@redhat.com>, Vitaly Kuznetsov <vkuznets@redhat.com>, LKML <linux-kernel@vger.kernel.org>, Michal Hocko <mhocko@suse.com> Subject: [PATCH 1/2] mm: drop migrate type checks from has_unmovable_pages Date: Fri, 13 Oct 2017 14:00:12 +0200 [thread overview] Message-ID: <20171013120013.698-1-mhocko@kernel.org> (raw) In-Reply-To: <20171013115835.zaehapuucuzl2vlv@dhcp22.suse.cz> From: Michal Hocko <mhocko@suse.com> Michael has noticed that the memory offline tries to migrate kernel code pages when doing echo 0 > /sys/devices/system/memory/memory0/online The current implementation will fail the operation after several failed page migration attempts but we shouldn't even attempt to migrate that memory and fail right away because this memory is clearly not migrateable. This will become a real problem when we drop the retry loop counter resp. timeout. The real problem is in has_unmovable_pages in fact. We should fail if there are any non migrateable pages in the area. In orther to guarantee that remove the migrate type checks because MIGRATE_MOVABLE is not guaranteed to contain only migrateable pages. It is merely a heuristic. Similarly MIGRATE_CMA does guarantee that the page allocator doesn't allocate any non-migrateable pages from the block but CMA allocations themselves are unlikely to migrateable. Therefore remove both checks. Reported-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Michal Hocko <mhocko@suse.com> --- mm/page_alloc.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 3badcedf96a7..ad0294ab3e4f 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -7355,9 +7355,6 @@ bool has_unmovable_pages(struct zone *zone, struct page *page, int count, */ if (zone_idx(zone) == ZONE_MOVABLE) return false; - mt = get_pageblock_migratetype(page); - if (mt == MIGRATE_MOVABLE || is_migrate_cma(mt)) - return false; pfn = page_to_pfn(page); for (found = 0, iter = 0; iter < pageblock_nr_pages; iter++) { -- 2.14.2
WARNING: multiple messages have this Message-ID (diff)
From: Michal Hocko <mhocko@kernel.org> To: linux-mm@kvack.org Cc: Michael Ellerman <mpe@ellerman.id.au>, Vlastimil Babka <vbabka@suse.cz>, Andrew Morton <akpm@linux-foundation.org>, KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>, Reza Arbab <arbab@linux.vnet.ibm.com>, Yasuaki Ishimatsu <yasu.isimatu@gmail.com>, qiuxishi@huawei.com, Igor Mammedov <imammedo@redhat.com>, Vitaly Kuznetsov <vkuznets@redhat.com>, LKML <linux-kernel@vger.kernel.org>, Michal Hocko <mhocko@suse.com> Subject: [PATCH 1/2] mm: drop migrate type checks from has_unmovable_pages Date: Fri, 13 Oct 2017 14:00:12 +0200 [thread overview] Message-ID: <20171013120013.698-1-mhocko@kernel.org> (raw) In-Reply-To: <20171013115835.zaehapuucuzl2vlv@dhcp22.suse.cz> From: Michal Hocko <mhocko@suse.com> Michael has noticed that the memory offline tries to migrate kernel code pages when doing echo 0 > /sys/devices/system/memory/memory0/online The current implementation will fail the operation after several failed page migration attempts but we shouldn't even attempt to migrate that memory and fail right away because this memory is clearly not migrateable. This will become a real problem when we drop the retry loop counter resp. timeout. The real problem is in has_unmovable_pages in fact. We should fail if there are any non migrateable pages in the area. In orther to guarantee that remove the migrate type checks because MIGRATE_MOVABLE is not guaranteed to contain only migrateable pages. It is merely a heuristic. Similarly MIGRATE_CMA does guarantee that the page allocator doesn't allocate any non-migrateable pages from the block but CMA allocations themselves are unlikely to migrateable. Therefore remove both checks. Reported-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Michal Hocko <mhocko@suse.com> --- mm/page_alloc.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 3badcedf96a7..ad0294ab3e4f 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -7355,9 +7355,6 @@ bool has_unmovable_pages(struct zone *zone, struct page *page, int count, */ if (zone_idx(zone) == ZONE_MOVABLE) return false; - mt = get_pageblock_migratetype(page); - if (mt == MIGRATE_MOVABLE || is_migrate_cma(mt)) - return false; pfn = page_to_pfn(page); for (found = 0, iter = 0; iter < pageblock_nr_pages; iter++) { -- 2.14.2 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2017-10-13 12:00 UTC|newest] Thread overview: 102+ messages / expand[flat|nested] mbox.gz Atom feed top 2017-09-18 7:08 [PATCH v2 0/2] mm, memory_hotplug: redefine memory offline retry logic Michal Hocko 2017-09-18 7:08 ` Michal Hocko 2017-09-18 7:08 ` [PATCH 1/2] mm, memory_hotplug: do not fail offlining too early Michal Hocko 2017-09-18 7:08 ` Michal Hocko 2017-10-10 12:05 ` Michael Ellerman 2017-10-10 12:05 ` Michael Ellerman 2017-10-10 12:27 ` Michal Hocko 2017-10-10 12:27 ` Michal Hocko 2017-10-11 2:37 ` Michael Ellerman 2017-10-11 2:37 ` Michael Ellerman 2017-10-11 5:19 ` Michael Ellerman 2017-10-11 5:19 ` Michael Ellerman 2017-10-11 14:05 ` Anshuman Khandual 2017-10-11 14:05 ` Anshuman Khandual 2017-10-11 14:16 ` Michal Hocko 2017-10-11 14:16 ` Michal Hocko 2017-10-11 6:51 ` Michal Hocko 2017-10-11 6:51 ` Michal Hocko 2017-10-11 8:04 ` Vlastimil Babka 2017-10-11 8:04 ` Vlastimil Babka 2017-10-11 8:13 ` Michal Hocko 2017-10-11 8:13 ` Michal Hocko 2017-10-11 11:17 ` Vlastimil Babka 2017-10-11 11:17 ` Vlastimil Babka 2017-10-11 11:24 ` Michal Hocko 2017-10-11 11:24 ` Michal Hocko 2017-10-13 11:42 ` Michael Ellerman 2017-10-13 11:42 ` Michael Ellerman 2017-10-13 11:58 ` Michal Hocko 2017-10-13 11:58 ` Michal Hocko 2017-10-13 12:00 ` Michal Hocko [this message] 2017-10-13 12:00 ` [PATCH 1/2] mm: drop migrate type checks from has_unmovable_pages Michal Hocko 2017-10-13 12:00 ` [PATCH 2/2] mm, page_alloc: fail has_unmovable_pages when seeing reserved pages Michal Hocko 2017-10-13 12:00 ` Michal Hocko 2017-10-13 12:04 ` Vlastimil Babka 2017-10-13 12:04 ` Vlastimil Babka 2017-10-13 12:07 ` Michal Hocko 2017-10-13 12:07 ` Michal Hocko 2017-10-17 13:03 ` Vlastimil Babka 2017-10-17 13:03 ` Vlastimil Babka 2017-10-17 11:41 ` [PATCH 1/2] mm: drop migrate type checks from has_unmovable_pages Michael Ellerman 2017-10-17 11:41 ` Michael Ellerman 2017-10-17 12:03 ` Michal Hocko 2017-10-17 12:03 ` Michal Hocko 2017-10-17 13:02 ` Vlastimil Babka 2017-10-17 13:02 ` Vlastimil Babka 2017-10-19 2:51 ` Joonsoo Kim 2017-10-19 2:51 ` Joonsoo Kim 2017-10-19 7:15 ` Michal Hocko 2017-10-19 7:15 ` Michal Hocko 2017-10-19 7:33 ` Joonsoo Kim 2017-10-19 7:33 ` Joonsoo Kim 2017-10-19 8:20 ` Michal Hocko 2017-10-19 8:20 ` Michal Hocko 2017-10-19 12:21 ` Michal Hocko 2017-10-19 12:21 ` Michal Hocko 2017-10-20 2:13 ` Joonsoo Kim 2017-10-20 2:13 ` Joonsoo Kim 2017-10-20 5:59 ` Michal Hocko 2017-10-20 5:59 ` Michal Hocko 2017-10-20 6:50 ` Joonsoo Kim 2017-10-20 6:50 ` Joonsoo Kim 2017-10-20 7:02 ` Michal Hocko 2017-10-20 7:02 ` Michal Hocko 2017-10-23 5:23 ` Joonsoo Kim 2017-10-23 5:23 ` Joonsoo Kim 2017-10-23 8:10 ` Michal Hocko 2017-10-23 8:10 ` Michal Hocko 2017-10-24 4:44 ` Joonsoo Kim 2017-10-24 4:44 ` Joonsoo Kim 2017-10-24 7:44 ` Michal Hocko 2017-10-24 7:44 ` Michal Hocko 2017-10-24 8:12 ` Vlastimil Babka 2017-10-24 8:12 ` Vlastimil Babka 2017-10-24 12:25 ` Michal Hocko 2017-10-24 12:25 ` Michal Hocko 2017-10-26 2:47 ` Joonsoo Kim 2017-10-26 2:47 ` Joonsoo Kim 2017-10-26 7:41 ` Michal Hocko 2017-10-26 7:41 ` Michal Hocko 2017-10-20 7:22 ` Xishi Qiu 2017-10-20 7:22 ` Xishi Qiu 2017-10-20 8:17 ` Michal Hocko 2017-10-20 8:17 ` Michal Hocko 2017-10-23 5:26 ` Joonsoo Kim 2017-10-23 5:26 ` Joonsoo Kim 2017-10-26 13:04 ` Vlastimil Babka 2017-10-26 13:04 ` Vlastimil Babka 2017-10-26 13:59 ` Michal Hocko 2017-10-26 13:59 ` Michal Hocko 2017-09-18 7:08 ` [PATCH 2/2] mm, memory_hotplug: remove timeout from __offline_memory Michal Hocko 2017-09-18 7:08 ` Michal Hocko [not found] <AM3PR04MB14892A9D6D2FBCE21B8C1F0FF12B0@AM3PR04MB1489.eurprd04.prod.outlook.com> 2017-11-13 7:33 ` [PATCH 1/2] mm: drop migrate type checks from has_unmovable_pages Ran Wang 2017-11-13 7:33 ` Ran Wang 2017-11-13 11:02 ` Michal Hocko 2017-11-13 11:02 ` Michal Hocko 2017-11-14 6:10 ` Ran Wang 2017-11-14 6:10 ` Ran Wang 2017-11-14 7:06 ` Michal Hocko 2017-11-14 7:06 ` Michal Hocko 2017-11-14 7:45 ` Ran Wang 2017-11-14 7:45 ` Ran Wang
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