From: Dave Hansen <firstname.lastname@example.org> To: email@example.com Cc: firstname.lastname@example.org, Dave Hansen <email@example.com>, firstname.lastname@example.org, email@example.com, firstname.lastname@example.org, email@example.com, firstname.lastname@example.org, email@example.com, firstname.lastname@example.org Subject: [PATCH 00/10] [v7][RESEND] Migrate Pages in lieu of discard Date: Thu, 01 Apr 2021 11:32:16 -0700 [thread overview] Message-ID: <20210401183216.443C4443@viggo.jf.intel.com> (raw) I'm resending this because I forgot to cc the mailing lists on the post yesterday. Sorry for the noise. Please reply to this series. The full series is also available here: https://github.com/hansendc/linux/tree/automigrate-20210331 which also inclues some vm.zone_reclaim_mode sysctl ABI fixup prerequisites: https://github.com/hansendc/linux/commit/18daad8f0181a2da57cb43e595303c2ef5bd7b6e https://github.com/hansendc/linux/commit/a873f3b6f250581072ab36f2735a3aa341e36705 There are no major changes since the last post. -- We're starting to see systems with more and more kinds of memory such as Intel's implementation of persistent memory. Let's say you have a system with some DRAM and some persistent memory. Today, once DRAM fills up, reclaim will start and some of the DRAM contents will be thrown out. Allocations will, at some point, start falling over to the slower persistent memory. That has two nasty properties. First, the newer allocations can end up in the slower persistent memory. Second, reclaimed data in DRAM are just discarded even if there are gobs of space in persistent memory that could be used. This set implements a solution to these problems. At the end of the reclaim process in shrink_page_list() just before the last page refcount is dropped, the page is migrated to persistent memory instead of being dropped. While I've talked about a DRAM/PMEM pairing, this approach would function in any environment where memory tiers exist. This is not perfect. It "strands" pages in slower memory and never brings them back to fast DRAM. Huang Ying has follow-on work which repurposes autonuma to promote hot pages back to DRAM. This is also all based on an upstream mechanism that allows persistent memory to be onlined and used as if it were volatile: http://lkml.kernel.org/r/20190124231441.37A4A305@viggo.jf.intel.com == Open Issues == * Memory policies and cpusets that, for instance, restrict allocations to DRAM can be demoted to PMEM whenever they opt in to this new mechanism. A cgroup-level API to opt-in or opt-out of these migrations will likely be required as a follow-on. * Could be more aggressive about where anon LRU scanning occurs since it no longer necessarily involves I/O. get_scan_count() for instance says: "If we have no swap space, do not bother scanning anon pages" -- Documentation/admin-guide/sysctl/vm.rst | 12 + include/linux/migrate.h | 14 +- include/linux/swap.h | 3 +- include/linux/vm_event_item.h | 2 + include/trace/events/migrate.h | 3 +- include/uapi/linux/mempolicy.h | 1 + mm/compaction.c | 3 +- mm/gup.c | 3 +- mm/internal.h | 5 + mm/memory-failure.c | 4 +- mm/memory_hotplug.c | 4 +- mm/mempolicy.c | 8 +- mm/migrate.c | 315 +++++++++++++++++++++++- mm/page_alloc.c | 11 +- mm/vmscan.c | 158 +++++++++++- mm/vmstat.c | 2 + 16 files changed, 520 insertions(+), 28 deletions(-) -- Changes since (automigrate-20210304): * Add ack/review tags * Remove duplicate synchronize_rcu() call Changes since (automigrate-20210122): * move from GFP_HIGHUSER -> GFP_HIGHUSER_MOVABLE since pages *are* movable. * Separate out helpers that check for being able to relaim anonymous pages versus being able to meaningfully scan the anon LRU. Changes since (automigrate-20200818): * Fall back to normal reclaim when demotion fails * Fix some compile issues, when page migration and NUMA are off Changes since (automigrate-20201007): * separate out checks for "can scan anon LRU" from "can actually swap anon pages right now". Previous series conflated them and may have been overly aggressive scanning LRU * add MR_DEMOTION to tracepoint header * remove unnecessary hugetlb page check Changes since (https://lwn.net/Articles/824830/): * Use higher-level migrate_pages() API approach from Yang Shi's earlier patches. * made sure to actually check node_reclaim_mode's new bit * disabled migration entirely before introducing RECLAIM_MIGRATE * Replace GFP_NOWAIT with explicit __GFP_KSWAPD_RECLAIM and comment why we want that. * Comment on effects of that keep multiple source nodes from sharing target nodes Cc: Yang Shi <email@example.com> Cc: David Rientjes <firstname.lastname@example.org> Cc: Huang Ying <email@example.com> Cc: Dan Williams <firstname.lastname@example.org> Cc: David Hildenbrand <email@example.com> Cc: osalvador <firstname.lastname@example.org> Cc: Huang Ying <email@example.com> Cc: Wei Xu <firstname.lastname@example.org>
next reply other threads:[~2021-04-01 18:56 UTC|newest] Thread overview: 62+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-04-01 18:32 Dave Hansen [this message] 2021-04-01 18:32 ` [PATCH 01/10] mm/numa: node demotion data structure and lookup Dave Hansen 2021-04-08 8:03 ` Oscar Salvador 2021-04-08 21:29 ` Dave Hansen 2021-04-09 5:32 ` Wei Xu 2021-04-01 18:32 ` [PATCH 02/10] mm/numa: automatically generate node migration order Dave Hansen 2021-04-08 8:26 ` Oscar Salvador 2021-04-08 21:51 ` Dave Hansen 2021-04-09 8:17 ` Oscar Salvador 2021-04-10 3:07 ` Wei Xu 2021-04-14 8:08 ` Oscar Salvador 2021-04-14 8:11 ` Oscar Salvador 2021-04-14 8:12 ` David Hildenbrand 2021-04-14 8:14 ` Oscar Salvador 2021-04-14 8:20 ` David Hildenbrand 2021-04-15 4:07 ` Wei Xu 2021-04-15 15:35 ` Dave Hansen 2021-04-15 20:25 ` Wei Xu 2021-04-01 18:32 ` [PATCH 03/10] mm/migrate: update node demotion order during on hotplug events Dave Hansen 2021-04-08 9:52 ` Oscar Salvador 2021-04-09 10:14 ` Oscar Salvador 2021-04-09 10:15 ` Oscar Salvador 2021-04-09 18:59 ` David Hildenbrand 2021-04-12 7:19 ` Oscar Salvador 2021-04-12 9:19 ` David Hildenbrand 2021-04-01 18:32 ` [PATCH 04/10] mm/migrate: make migrate_pages() return nr_succeeded Dave Hansen 2021-04-01 22:39 ` Wei Xu [not found] ` <CAAPL-u-o-M2T25xBtSoipYjUnu+3aJNcJ9uS84yKaAnbrXpefw@mail.gmail.com> 2021-04-01 23:21 ` Dave Hansen 2021-04-08 10:14 ` Oscar Salvador 2021-04-08 17:26 ` Yang Shi 2021-04-08 18:17 ` Oscar Salvador 2021-04-08 18:21 ` Oscar Salvador 2021-04-08 20:40 ` Yang Shi 2021-04-09 5:06 ` Oscar Salvador 2021-04-09 5:43 ` Wei Xu 2021-04-09 15:43 ` Yang Shi 2021-04-09 15:50 ` Dave Hansen 2021-04-09 18:47 ` Wei Xu 2021-04-09 20:10 ` Yang Shi 2021-04-01 18:32 ` [PATCH 05/10] mm/migrate: demote pages during reclaim Dave Hansen 2021-04-01 20:01 ` Yang Shi 2021-04-01 22:58 ` Dave Hansen 2021-04-08 10:47 ` Oscar Salvador 2021-04-10 3:35 ` Wei Xu 2021-04-01 18:32 ` [PATCH 06/10] mm/vmscan: add page demotion counter Dave Hansen 2021-04-10 3:40 ` Wei Xu 2021-04-01 18:32 ` [PATCH 07/10] mm/vmscan: add helper for querying ability to age anonymous pages Dave Hansen 2021-04-07 18:40 ` Wei Xu 2021-04-09 8:31 ` Oscar Salvador 2021-04-01 18:32 ` [PATCH 08/10] mm/vmscan: Consider anonymous pages without swap Dave Hansen 2021-04-02 0:55 ` Wei Xu 2021-04-01 18:32 ` [PATCH 09/10] mm/vmscan: never demote for memcg reclaim Dave Hansen 2021-04-02 0:18 ` Wei Xu 2021-04-01 18:32 ` [PATCH 10/10] mm/migrate: new zone_reclaim_mode to enable reclaim migration Dave Hansen 2021-04-01 20:06 ` Yang Shi 2021-04-10 4:10 ` Wei Xu 2021-04-16 12:35 ` [PATCH 00/10] [v7][RESEND] Migrate Pages in lieu of discard Michal Hocko 2021-04-16 14:26 ` Dave Hansen 2021-04-16 15:02 ` Michal Hocko 2021-04-21 2:39 ` Huang, Ying 2021-05-07 6:14 ` Huang, Ying 2021-06-11 5:50 ` Huang, Ying
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