From: Vlastimil Babka <vbabka@suse.cz> To: Michal Hocko <mhocko@kernel.org> Cc: Michael Ellerman <mpe@ellerman.id.au>, 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>, linux-mm@kvack.org, LKML <linux-kernel@vger.kernel.org> Subject: Re: [PATCH 1/2] mm, memory_hotplug: do not fail offlining too early Date: Wed, 11 Oct 2017 13:17:13 +0200 [thread overview] Message-ID: <c1b5f3cf-db9b-1cb8-dd0d-312940b7b953@suse.cz> (raw) In-Reply-To: <20171011081317.b2cdnhjdyzgdo3up@dhcp22.suse.cz> On 10/11/2017 10:13 AM, Michal Hocko wrote: > On Wed 11-10-17 10:04:39, Vlastimil Babka wrote: >> On 10/11/2017 08:51 AM, Michal Hocko wrote: > [...] >>> This is really strange! As you write in other email the page is >>> reserved. That means that some of the earlier checks >>> if (zone_idx(zone) == ZONE_MOVABLE) >>> return false; >>> mt = get_pageblock_migratetype(page); >>> if (mt == MIGRATE_MOVABLE || is_migrate_cma(mt)) >> >> The MIGRATE_MOVABLE check is indeed bogus, because that doesn't >> guarantee there are no unmovable pages in the block (CMA block OTOH >> should be a guarantee). > > OK, thanks for confirmation. I will remove the MIGRATE_MOVABLE check > here. Do you think it is worth removing CMA check as well? This is > merely an optimization AFAIU because we do not have to check the full > pageblockworth of pfns. Actually, we should remove the CMA part as well. It's true that MIGRATE_CMA does guarantee that the *buddy allocator* won't allocate non-MOVABLE pages from the pageblock. But if the memory got allocated as an actual CMA allocation (alloc_contig...) it will almost certainly not be movable. > Anyway, let's way for Michael to confirm it really helps. If yes I will > post a full patch and ask Andrew to add it as a prerequisite for this > patch when sending to Linus to prevent the regression. >
WARNING: multiple messages have this Message-ID (diff)
From: Vlastimil Babka <vbabka@suse.cz> To: Michal Hocko <mhocko@kernel.org> Cc: Michael Ellerman <mpe@ellerman.id.au>, 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>, linux-mm@kvack.org, LKML <linux-kernel@vger.kernel.org> Subject: Re: [PATCH 1/2] mm, memory_hotplug: do not fail offlining too early Date: Wed, 11 Oct 2017 13:17:13 +0200 [thread overview] Message-ID: <c1b5f3cf-db9b-1cb8-dd0d-312940b7b953@suse.cz> (raw) In-Reply-To: <20171011081317.b2cdnhjdyzgdo3up@dhcp22.suse.cz> On 10/11/2017 10:13 AM, Michal Hocko wrote: > On Wed 11-10-17 10:04:39, Vlastimil Babka wrote: >> On 10/11/2017 08:51 AM, Michal Hocko wrote: > [...] >>> This is really strange! As you write in other email the page is >>> reserved. That means that some of the earlier checks >>> if (zone_idx(zone) == ZONE_MOVABLE) >>> return false; >>> mt = get_pageblock_migratetype(page); >>> if (mt == MIGRATE_MOVABLE || is_migrate_cma(mt)) >> >> The MIGRATE_MOVABLE check is indeed bogus, because that doesn't >> guarantee there are no unmovable pages in the block (CMA block OTOH >> should be a guarantee). > > OK, thanks for confirmation. I will remove the MIGRATE_MOVABLE check > here. Do you think it is worth removing CMA check as well? This is > merely an optimization AFAIU because we do not have to check the full > pageblockworth of pfns. Actually, we should remove the CMA part as well. It's true that MIGRATE_CMA does guarantee that the *buddy allocator* won't allocate non-MOVABLE pages from the pageblock. But if the memory got allocated as an actual CMA allocation (alloc_contig...) it will almost certainly not be movable. > Anyway, let's way for Michael to confirm it really helps. If yes I will > post a full patch and ask Andrew to add it as a prerequisite for this > patch when sending to Linus to prevent the regression. > -- 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:[~2017-10-11 11:17 UTC|newest] Thread overview: 112+ 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 [this message] 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 ` [PATCH 1/2] mm: drop migrate type checks from has_unmovable_pages Michal Hocko 2017-10-13 12:00 ` 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 -- strict thread matches above, loose matches on Subject: below -- 2017-09-04 8:21 [PATCH 0/2] mm, memory_hotplug: redefine memory offline retry logic Michal Hocko 2017-09-04 8:21 ` [PATCH 1/2] mm, memory_hotplug: do not fail offlining too early Michal Hocko 2017-09-04 8:21 ` Michal Hocko 2017-09-05 6:29 ` Anshuman Khandual 2017-09-05 6:29 ` Anshuman Khandual 2017-09-05 7:13 ` Michal Hocko 2017-09-05 7:13 ` Michal Hocko 2017-09-08 17:26 ` Vlastimil Babka 2017-09-08 17:26 ` Vlastimil Babka 2017-09-11 8:17 ` Michal Hocko 2017-09-11 8:17 ` Michal Hocko 2017-09-13 11:41 ` Vlastimil Babka 2017-09-13 11:41 ` Vlastimil Babka 2017-09-13 12:10 ` Michal Hocko 2017-09-13 12:10 ` Michal Hocko 2017-09-13 12:14 ` Michal Hocko 2017-09-13 12:14 ` Michal Hocko 2017-09-13 12:19 ` Vlastimil Babka 2017-09-13 12:19 ` Vlastimil Babka 2017-09-13 12:32 ` Michal Hocko 2017-09-13 12:32 ` Michal Hocko
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