[00/34] put_user_pages(): miscellaneous call sites
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john.hubbard@gmail.com Aug. 2, 2019, 2:16 a.m. UTC
From: John Hubbard <jhubbard@nvidia.com>

Hi,

These are best characterized as miscellaneous conversions: many (not all)
call sites that don't involve biovec or iov_iter, nor mm/. It also leaves
out a few call sites that require some more work. These are mostly pretty
simple ones.

It's probably best to send all of these via Andrew's -mm tree, assuming
that there are no significant merge conflicts with ongoing work in other
trees (which I doubt, given that these are small changes).

These patches apply to the latest linux.git. Patch #1 is also already in
Andrew's tree, but given the broad non-linux-mm Cc list, I thought it
would be more convenient to just include that patch here, so that people
can use linux.git as the base--even though these are probably destined
for linux-mm.

This is part a tree-wide conversion, as described in commit fc1d8e7cca2d
("mm: introduce put_user_page*(), placeholder versions"). That commit
has an extensive description of the problem and the planned steps to
solve it, but the highlites are:

1) Provide put_user_page*() routines, intended to be used
for releasing pages that were pinned via get_user_pages*().

2) Convert all of the call sites for get_user_pages*(), to
invoke put_user_page*(), instead of put_page(). This involves dozens of
call sites, and will take some time.

3) After (2) is complete, use get_user_pages*() and put_user_page*() to
implement tracking of these pages. This tracking will be separate from
the existing struct page refcounting.

4) Use the tracking and identification of these pages, to implement
special handling (especially in writeback paths) when the pages are
backed by a filesystem.

And a few references, also from that commit:

[1] https://lwn.net/Articles/774411/ : "DMA and get_user_pages()"
[2] https://lwn.net/Articles/753027/ : "The Trouble with get_user_pages()"


Ira Weiny (1):
  fs/binfmt_elf: convert put_page() to put_user_page*()

John Hubbard (33):
  mm/gup: add make_dirty arg to put_user_pages_dirty_lock()
  net/rds: convert put_page() to put_user_page*()
  net/ceph: convert put_page() to put_user_page*()
  x86/kvm: convert put_page() to put_user_page*()
  drm/etnaviv: convert release_pages() to put_user_pages()
  drm/i915: convert put_page() to put_user_page*()
  drm/radeon: convert put_page() to put_user_page*()
  media/ivtv: convert put_page() to put_user_page*()
  media/v4l2-core/mm: convert put_page() to put_user_page*()
  genwqe: convert put_page() to put_user_page*()
  scif: convert put_page() to put_user_page*()
  vmci: convert put_page() to put_user_page*()
  rapidio: convert put_page() to put_user_page*()
  oradax: convert put_page() to put_user_page*()
  staging/vc04_services: convert put_page() to put_user_page*()
  drivers/tee: convert put_page() to put_user_page*()
  vfio: convert put_page() to put_user_page*()
  fbdev/pvr2fb: convert put_page() to put_user_page*()
  fsl_hypervisor: convert put_page() to put_user_page*()
  xen: convert put_page() to put_user_page*()
  fs/exec.c: convert put_page() to put_user_page*()
  orangefs: convert put_page() to put_user_page*()
  uprobes: convert put_page() to put_user_page*()
  futex: convert put_page() to put_user_page*()
  mm/frame_vector.c: convert put_page() to put_user_page*()
  mm/gup_benchmark.c: convert put_page() to put_user_page*()
  mm/memory.c: convert put_page() to put_user_page*()
  mm/madvise.c: convert put_page() to put_user_page*()
  mm/process_vm_access.c: convert put_page() to put_user_page*()
  crypt: convert put_page() to put_user_page*()
  nfs: convert put_page() to put_user_page*()
  goldfish_pipe: convert put_page() to put_user_page*()
  kernel/events/core.c: convert put_page() to put_user_page*()

 arch/x86/kvm/svm.c                            |   4 +-
 crypto/af_alg.c                               |   7 +-
 drivers/gpu/drm/etnaviv/etnaviv_gem.c         |   4 +-
 drivers/gpu/drm/i915/gem/i915_gem_userptr.c   |   9 +-
 drivers/gpu/drm/radeon/radeon_ttm.c           |   2 +-
 drivers/infiniband/core/umem.c                |   5 +-
 drivers/infiniband/hw/hfi1/user_pages.c       |   5 +-
 drivers/infiniband/hw/qib/qib_user_pages.c    |   5 +-
 drivers/infiniband/hw/usnic/usnic_uiom.c      |   5 +-
 drivers/infiniband/sw/siw/siw_mem.c           |  10 +-
 drivers/media/pci/ivtv/ivtv-udma.c            |  14 +--
 drivers/media/pci/ivtv/ivtv-yuv.c             |  10 +-
 drivers/media/v4l2-core/videobuf-dma-sg.c     |   3 +-
 drivers/misc/genwqe/card_utils.c              |  17 +--
 drivers/misc/mic/scif/scif_rma.c              |  17 ++-
 drivers/misc/vmw_vmci/vmci_context.c          |   2 +-
 drivers/misc/vmw_vmci/vmci_queue_pair.c       |  11 +-
 drivers/platform/goldfish/goldfish_pipe.c     |   9 +-
 drivers/rapidio/devices/rio_mport_cdev.c      |   9 +-
 drivers/sbus/char/oradax.c                    |   2 +-
 .../interface/vchiq_arm/vchiq_2835_arm.c      |  10 +-
 drivers/tee/tee_shm.c                         |  10 +-
 drivers/vfio/vfio_iommu_type1.c               |   8 +-
 drivers/video/fbdev/pvr2fb.c                  |   3 +-
 drivers/virt/fsl_hypervisor.c                 |   7 +-
 drivers/xen/gntdev.c                          |   5 +-
 drivers/xen/privcmd.c                         |   7 +-
 fs/binfmt_elf.c                               |   2 +-
 fs/binfmt_elf_fdpic.c                         |   2 +-
 fs/exec.c                                     |   2 +-
 fs/nfs/direct.c                               |   4 +-
 fs/orangefs/orangefs-bufmap.c                 |   7 +-
 include/linux/mm.h                            |   5 +-
 kernel/events/core.c                          |   2 +-
 kernel/events/uprobes.c                       |   6 +-
 kernel/futex.c                                |  10 +-
 mm/frame_vector.c                             |   4 +-
 mm/gup.c                                      | 115 ++++++++----------
 mm/gup_benchmark.c                            |   2 +-
 mm/madvise.c                                  |   2 +-
 mm/memory.c                                   |   2 +-
 mm/process_vm_access.c                        |  18 +--
 net/ceph/pagevec.c                            |   8 +-
 net/rds/info.c                                |   5 +-
 net/rds/message.c                             |   2 +-
 net/rds/rdma.c                                |  15 ++-
 virt/kvm/kvm_main.c                           |   4 +-
 47 files changed, 151 insertions(+), 266 deletions(-)

Comments

John Hubbard Aug. 2, 2019, 2:39 a.m. UTC | #1
On 8/1/19 7:16 PM, john.hubbard@gmail.com wrote:
> From: John Hubbard <jhubbard@nvidia.com>
> 
> Hi,
> 
> These are best characterized as miscellaneous conversions: many (not all)
> call sites that don't involve biovec or iov_iter, nor mm/. It also leaves
> out a few call sites that require some more work. These are mostly pretty
> simple ones.
> 
> It's probably best to send all of these via Andrew's -mm tree, assuming
> that there are no significant merge conflicts with ongoing work in other
> trees (which I doubt, given that these are small changes).
> 

In case anyone is wondering, this truncated series is due to a script failure:
git-send-email chokes when it hits email addresses whose names have a
comma in them, as happened here with patch 0003.  

Please disregard this set and reply to the other thread.

thanks,
Peter Zijlstra Aug. 2, 2019, 8:05 a.m. UTC | #2
On Thu, Aug 01, 2019 at 07:16:19PM -0700, john.hubbard@gmail.com wrote:

> This is part a tree-wide conversion, as described in commit fc1d8e7cca2d
> ("mm: introduce put_user_page*(), placeholder versions"). That commit
> has an extensive description of the problem and the planned steps to
> solve it, but the highlites are:

That is one horridly mangled Changelog there :-/ It looks like it's
partially duplicated.

Anyway; no objections to any of that, but I just wanted to mention that
there are other problems with long term pinning that haven't been
mentioned, notably they inhibit compaction.

A long time ago I proposed an interface to mark pages as pinned, such
that we could run compaction before we actually did the pinning.
John Hubbard Aug. 2, 2019, 7:33 p.m. UTC | #3
On 8/2/19 1:05 AM, Peter Zijlstra wrote:
> On Thu, Aug 01, 2019 at 07:16:19PM -0700, john.hubbard@gmail.com wrote:
> 
>> This is part a tree-wide conversion, as described in commit fc1d8e7cca2d
>> ("mm: introduce put_user_page*(), placeholder versions"). That commit
>> has an extensive description of the problem and the planned steps to
>> solve it, but the highlites are:
> 
> That is one horridly mangled Changelog there :-/ It looks like it's
> partially duplicated.

Yeah. It took so long to merge that I think I was no longer able to
actually see the commit description, after N readings. sigh

> 
> Anyway; no objections to any of that, but I just wanted to mention that
> there are other problems with long term pinning that haven't been
> mentioned, notably they inhibit compaction.
> 
> A long time ago I proposed an interface to mark pages as pinned, such
> that we could run compaction before we actually did the pinning.
> 

This is all heading toward marking pages as pinned, so we should finally
get there.  I'll post the RFC for tracking pinned pages shortly.


thanks,