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* [PATCH 0/6] prohibit pinning pages in ZONE_MOVABLE
@ 2020-12-02  5:23 Pavel Tatashin
  2020-12-02  5:23 ` [PATCH 1/6] mm/gup: perform check_dax_vmas only when FS_DAX is enabled Pavel Tatashin
                   ` (6 more replies)
  0 siblings, 7 replies; 67+ messages in thread
From: Pavel Tatashin @ 2020-12-02  5:23 UTC (permalink / raw)
  To: pasha.tatashin, linux-kernel, linux-mm, akpm, vbabka, mhocko,
	david, osalvador, dan.j.williams, sashal, tyhicks,
	iamjoonsoo.kim, mike.kravetz, rostedt, mingo, jgg, peterz,
	mgorman, willy, rientjes, jhubbard

When page is pinned it cannot be moved and its physical address stays
the same until pages is unpinned.

This is useful functionality to allows userland to implementation DMA
access. For example, it is used by vfio in vfio_pin_pages().

However, this functionality breaks memory hotplug/hotremove assumptions
that pages in ZONE_MOVABLE can always be migrated.

This patch series fixes this issue by forcing new allocations during
page pinning to omit ZONE_MOVABLE, and also to migrate any existing
pages from ZONE_MOVABLE during pinning.

It uses the same scheme logic that is currently used by CMA, and extends
the functionality for all allocations.

For more information read the discussion [1] about this problem.

[1] https://lore.kernel.org/lkml/CA+CK2bBffHBxjmb9jmSKacm0fJMinyt3Nhk8Nx6iudcQSj80_w@mail.gmail.com/

Pavel Tatashin (6):
  mm/gup: perform check_dax_vmas only when FS_DAX is enabled
  mm/gup: don't pin migrated cma pages in movable zone
  mm/gup: make __gup_longterm_locked common
  mm cma: rename PF_MEMALLOC_NOCMA to PF_MEMALLOC_NOMOVABLE
  mm: honor PF_MEMALLOC_NOMOVABLE for all allocations
  mm/gup: migrate pinned pages out of movable zone

 include/linux/migrate.h        |  1 +
 include/linux/sched.h          |  2 +-
 include/linux/sched/mm.h       | 21 +++------
 include/trace/events/migrate.h |  3 +-
 mm/gup.c                       | 82 +++++++++++++---------------------
 mm/hugetlb.c                   |  4 +-
 mm/page_alloc.c                | 26 ++++++-----
 7 files changed, 58 insertions(+), 81 deletions(-)

-- 
2.25.1


^ permalink raw reply	[flat|nested] 67+ messages in thread

end of thread, other threads:[~2020-12-08 13:25 UTC | newest]

Thread overview: 67+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-12-02  5:23 [PATCH 0/6] prohibit pinning pages in ZONE_MOVABLE Pavel Tatashin
2020-12-02  5:23 ` [PATCH 1/6] mm/gup: perform check_dax_vmas only when FS_DAX is enabled Pavel Tatashin
2020-12-02 16:22   ` Ira Weiny
2020-12-02 18:15     ` Pavel Tatashin
2020-12-02 16:29   ` Jason Gunthorpe
2020-12-02 18:16     ` Pavel Tatashin
2020-12-03  7:59   ` John Hubbard
2020-12-03 14:52     ` Pavel Tatashin
2020-12-02  5:23 ` [PATCH 2/6] mm/gup: don't pin migrated cma pages in movable zone Pavel Tatashin
2020-12-02 16:31   ` David Hildenbrand
2020-12-02 18:17     ` Pavel Tatashin
2020-12-03  8:01   ` John Hubbard
2020-12-03  8:46   ` Michal Hocko
2020-12-03 14:58     ` Pavel Tatashin
2020-12-02  5:23 ` [PATCH 3/6] mm/gup: make __gup_longterm_locked common Pavel Tatashin
2020-12-02 16:31   ` Ira Weiny
2020-12-02 16:33     ` Ira Weiny
2020-12-02 18:19       ` Pavel Tatashin
2020-12-03  0:03         ` Pavel Tatashin
2020-12-03  8:03   ` John Hubbard
2020-12-03 15:02     ` Pavel Tatashin
2020-12-02  5:23 ` [PATCH 4/6] mm cma: rename PF_MEMALLOC_NOCMA to PF_MEMALLOC_NOMOVABLE Pavel Tatashin
2020-12-03  8:04   ` John Hubbard
2020-12-03 15:02     ` Pavel Tatashin
2020-12-03  8:57   ` Michal Hocko
2020-12-03 15:02     ` Pavel Tatashin
2020-12-02  5:23 ` [PATCH 5/6] mm: honor PF_MEMALLOC_NOMOVABLE for all allocations Pavel Tatashin
2020-12-03  8:17   ` John Hubbard
2020-12-03 15:06     ` Pavel Tatashin
2020-12-03 16:51       ` John Hubbard
2020-12-03  9:17   ` Michal Hocko
2020-12-03 15:15     ` Pavel Tatashin
2020-12-04  8:43       ` Michal Hocko
2020-12-04  8:54         ` Michal Hocko
2020-12-04 16:07           ` Pavel Tatashin
2020-12-02  5:23 ` [PATCH 6/6] mm/gup: migrate pinned pages out of movable zone Pavel Tatashin
2020-12-02 16:35   ` Jason Gunthorpe
2020-12-03  0:19     ` Pavel Tatashin
2020-12-03  1:08       ` Jason Gunthorpe
2020-12-03  1:34         ` Pavel Tatashin
2020-12-03 14:17           ` Jason Gunthorpe
2020-12-03 16:40             ` Pavel Tatashin
2020-12-03 16:59               ` Jason Gunthorpe
2020-12-03 17:14                 ` Pavel Tatashin
2020-12-03 19:15                   ` Pavel Tatashin
2020-12-03 19:36                     ` Jason Gunthorpe
2020-12-04 16:24                       ` Pavel Tatashin
2020-12-04 17:06                         ` Jason Gunthorpe
2020-12-04 20:05             ` Daniel Jordan
2020-12-04 20:16               ` Pavel Tatashin
2020-12-08  2:27                 ` Daniel Jordan
2020-12-04 20:52               ` Jason Gunthorpe
2020-12-08  2:48                 ` Daniel Jordan
2020-12-08 13:24                   ` Jason Gunthorpe
2020-12-03  8:22   ` John Hubbard
2020-12-03 15:55     ` Pavel Tatashin
2020-12-04  4:13   ` Joonsoo Kim
2020-12-04 17:43     ` Pavel Tatashin
2020-12-07  7:13       ` Joonsoo Kim
2020-12-04  4:02 ` [PATCH 0/6] prohibit pinning pages in ZONE_MOVABLE Joonsoo Kim
2020-12-04 15:55   ` Pavel Tatashin
2020-12-04 16:10     ` Jason Gunthorpe
2020-12-04 17:50       ` Pavel Tatashin
2020-12-04 18:01         ` David Hildenbrand
2020-12-04 18:10           ` Pavel Tatashin
2020-12-07  7:12         ` Joonsoo Kim
2020-12-07 12:13           ` Michal Hocko

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