linux-toradex.git/include/linux/migrate.h, branch v5.10-rc3

mm/migrate: introduce a standard migration target allocation function

2020-08-12T17:58:02+00:00

There are some similar functions for migration target allocation.  Since
there is no fundamental difference, it's better to keep just one rather
than keeping all variants.  This patch implements base migration target
allocation function.  In the following patches, variants will be converted
to use this function.

Changes should be mechanical, but, unfortunately, there are some
differences.  First, some callers' nodemask is assgined to NULL since NULL
nodemask will be considered as all available nodes, that is,
&node_states[N_MEMORY].  Second, for hugetlb page allocation, gfp_mask is
redefined as regular hugetlb allocation gfp_mask plus __GFP_THISNODE if
user provided gfp_mask has it.  This is because future caller of this
function requires to set this node constaint.  Lastly, if provided nodeid
is NUMA_NO_NODE, nodeid is set up to the node where migration source
lives.  It helps to remove simple wrappers for setting up the nodeid.

Note that PageHighmem() call in previous function is changed to open-code
"is_highmem_idx()" since it provides more readability.

[akpm@linux-foundation.org: tweak patch title, per Vlastimil]
[akpm@linux-foundation.org: fix typo in comment]

Signed-off-by: Joonsoo Kim 
Signed-off-by: Andrew Morton 
Acked-by: Vlastimil Babka 
Acked-by: Michal Hocko 
Cc: Christoph Hellwig 
Cc: Mike Kravetz 
Cc: Naoya Horiguchi 
Cc: Roman Gushchin 
Link: http://lkml.kernel.org/r/1594622517-20681-6-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Linus Torvalds

mm/migrate: move migration helper from .h to .c

2020-08-12T17:58:02+00:00

It's not performance sensitive function.  Move it to .c.  This is a
preparation step for future change.

Signed-off-by: Joonsoo Kim 
Signed-off-by: Andrew Morton 
Reviewed-by: Vlastimil Babka 
Acked-by: Mike Kravetz 
Acked-by: Michal Hocko 
Cc: Christoph Hellwig 
Cc: Naoya Horiguchi 
Cc: Roman Gushchin 
Link: http://lkml.kernel.org/r/1594622517-20681-3-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Linus Torvalds

mm/notifier: add migration invalidation type

2020-07-28T19:20:33+00:00

Currently migrate_vma_setup() calls mmu_notifier_invalidate_range_start()
which flushes all device private page mappings whether or not a page is
being migrated to/from device private memory.

In order to not disrupt device mappings that are not being migrated, shift
the responsibility for clearing device private mappings to the device
driver and leave CPU page table unmapping handled by
migrate_vma_setup().

To support this, the caller of migrate_vma_setup() should always set
struct migrate_vma::pgmap_owner to a non NULL value that matches the
device private page->pgmap->owner. This value is then passed to the struct
mmu_notifier_range with a new event type which the driver's invalidation
function can use to avoid device MMU invalidations.

Link: https://lore.kernel.org/r/20200723223004.9586-4-rcampbell@nvidia.com
Signed-off-by: Ralph Campbell 
Signed-off-by: Jason Gunthorpe

mm/migrate: add a flags parameter to migrate_vma

2020-07-28T19:20:33+00:00

The src_owner field in struct migrate_vma is being used for two purposes,
it acts as a selection filter for which types of pages are to be migrated
and it identifies device private pages owned by the caller.

Split this into separate parameters so the src_owner field can be used
just to identify device private pages owned by the caller of
migrate_vma_setup().

Rename the src_owner field to pgmap_owner to reflect it is now used only
to identify which device private pages to migrate.

Link: https://lore.kernel.org/r/20200723223004.9586-3-rcampbell@nvidia.com
Signed-off-by: Ralph Campbell 
Reviewed-by: Bharata B Rao 
Signed-off-by: Jason Gunthorpe

mm: handle multiple owners of device private pages in migrate_vma

2020-03-26T17:33:38+00:00

Add a new src_owner field to struct migrate_vma.  If the field is set,
only device private pages with page->pgmap->owner equal to that field are
migrated.  If the field is not set only "normal" pages are migrated.

Fixes: df6ad69838fc ("mm/device-public-memory: device memory cache coherent with CPU")
Link: https://lore.kernel.org/r/20200316193216.920734-3-hch@lst.de
Signed-off-by: Christoph Hellwig 
Reviewed-by: Ralph Campbell 
Tested-by: Bharata B Rao 
Signed-off-by: Jason Gunthorpe

mm: remove the unused MIGRATE_PFN_DEVICE flag

2019-08-20T12:35:03+00:00

No one ever checks this flag, and we could easily get that information
from the page if needed.

Link: https://lore.kernel.org/r/20190814075928.23766-10-hch@lst.de
Signed-off-by: Christoph Hellwig 
Reviewed-by: Ralph Campbell 
Reviewed-by: Jason Gunthorpe 
Tested-by: Ralph Campbell 
Signed-off-by: Jason Gunthorpe

mm: remove the unused MIGRATE_PFN_ERROR flag

2019-08-20T12:35:03+00:00

Now that we can rely errors in the normal control flow there is no
need for this flag, remove it.

Link: https://lore.kernel.org/r/20190814075928.23766-9-hch@lst.de
Signed-off-by: Christoph Hellwig 
Reviewed-by: Ralph Campbell 
Tested-by: Ralph Campbell 
Signed-off-by: Jason Gunthorpe

mm: turn migrate_vma upside down

2019-08-20T12:35:02+00:00

There isn't any good reason to pass callbacks to migrate_vma.  Instead
we can just export the three steps done by this function to drivers and
let them sequence the operation without callbacks.  This removes a lot
of boilerplate code as-is, and will allow the drivers to drastically
improve code flow and error handling further on.

Link: https://lore.kernel.org/r/20190814075928.23766-2-hch@lst.de
Signed-off-by: Christoph Hellwig 
Reviewed-by: Ralph Campbell 
Tested-by: Ralph Campbell 
Signed-off-by: Jason Gunthorpe

mm: migrate: remove unused mode argument

2019-07-19T00:08:07+00:00

migrate_page_move_mapping() doesn't use the mode argument.  Remove it
and update callers accordingly.

Link: http://lkml.kernel.org/r/20190508210301.8472-1-keith.busch@intel.com
Signed-off-by: Keith Busch 
Reviewed-by: Zi Yan 
Cc: Mel Gorman 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: migrate: drop unused argument of migrate_page_move_mapping()

2018-12-28T20:11:51+00:00

All callers of migrate_page_move_mapping() now pass NULL for 'head'
argument.  Drop it.

Link: http://lkml.kernel.org/r/20181211172143.7358-7-jack@suse.cz
Signed-off-by: Jan Kara 
Acked-by: Mel Gorman 
Cc: Michal Hocko 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds