€•Q«      Œsphinx.addnodes”Œdocument”“”)”}”(Œ	rawsource”Œ ”Œchildren”]”(Œtranslations”ŒLanguagesNode”“”)”}”(hhh]”(h Œpending_xref”“”)”}”(hhh]”Œdocutils.nodes”ŒText”“”ŒChinese (Simplified)”…””}”Œparent”hsbaŒ
attributes”}”(Œids”]”Œclasses”]”Œnames”]”Œdupnames”]”Œbackrefs”]”Œ	refdomain”Œstd”Œreftype”Œdoc”Œ	reftarget”Œ%/translations/zh_CN/mm/page_migration”Œmodname”NŒ	classname”NŒrefexplicit”ˆuŒtagname”hhhubh)”}”(hhh]”hŒChinese (Traditional)”…””}”hh2sbah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ%/translations/zh_TW/mm/page_migration”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒItalian”…””}”hhFsbah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ%/translations/it_IT/mm/page_migration”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒJapanese”…””}”hhZsbah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ%/translations/ja_JP/mm/page_migration”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒKorean”…””}”hhnsbah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ%/translations/ko_KR/mm/page_migration”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒSpanish”…””}”hh‚sbah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ%/translations/sp_SP/mm/page_migration”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubeh}”(h]”h ]”h"]”h$]”h&]”Œcurrent_language”ŒEnglish”uh1h
hhŒ	_document”hŒsource”NŒline”NubhŒsection”“”)”}”(hhh]”(hŒtitle”“”)”}”(hŒPage migration”h]”hŒPage migration”…””}”(hh¨hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h¦hh£hžhhŸŒ?/var/lib/git/docbuild/linux/Documentation/mm/page_migration.rst”h KubhŒ	paragraph”“”)”}”(hX  Page migration allows moving the physical location of pages between
nodes in a NUMA system while the process is running. This means that the
virtual addresses that the process sees do not change. However, the
system rearranges the physical location of those pages.”h]”hX  Page migration allows moving the physical location of pages between
nodes in a NUMA system while the process is running. This means that the
virtual addresses that the process sees do not change. However, the
system rearranges the physical location of those pages.”…””}”(hh¹hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h Khh£hžhubh¸)”}”(hŒWAlso see Documentation/mm/hmm.rst for migrating pages to or from device
private memory.”h]”hŒWAlso see Documentation/mm/hmm.rst for migrating pages to or from device
private memory.”…””}”(hhÇhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h K
hh£hžhubh¸)”}”(hŒ§The main intent of page migration is to reduce the latency of memory accesses
by moving pages near to the processor where the process accessing that memory
is running.”h]”hŒ§The main intent of page migration is to reduce the latency of memory accesses
by moving pages near to the processor where the process accessing that memory
is running.”…””}”(hhÕhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h Khh£hžhubh¸)”}”(hXp  Page migration allows a process to manually relocate the node on which its
pages are located through the MF_MOVE and MF_MOVE_ALL options while setting
a new memory policy via mbind(). The pages of a process can also be relocated
from another process using the sys_migrate_pages() function call. The
migrate_pages() function call takes two sets of nodes and moves pages of a
process that are located on the from nodes to the destination nodes.
Page migration functions are provided by the numactl package by Andi Kleen
(a version later than 0.9.3 is required. Get it from
https://github.com/numactl/numactl.git). numactl provides libnuma
which provides an interface similar to other NUMA functionality for page
migration.  cat ``/proc/<pid>/numa_maps`` allows an easy review of where the
pages of a process are located. See also the numa_maps documentation in the
proc(5) man page.”h]”(hX;  Page migration allows a process to manually relocate the node on which its
pages are located through the MF_MOVE and MF_MOVE_ALL options while setting
a new memory policy via mbind(). The pages of a process can also be relocated
from another process using the sys_migrate_pages() function call. The
migrate_pages() function call takes two sets of nodes and moves pages of a
process that are located on the from nodes to the destination nodes.
Page migration functions are provided by the numactl package by Andi Kleen
(a version later than 0.9.3 is required. Get it from
”…””}”(hhãhžhhŸNh NubhŒ	reference”“”)”}”(hŒ&https://github.com/numactl/numactl.git”h]”hŒ&https://github.com/numactl/numactl.git”…””}”(hhíhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”Œrefuri”hïuh1hëhhãubhŒu). numactl provides libnuma
which provides an interface similar to other NUMA functionality for page
migration.  cat ”…””}”(hhãhžhhŸNh NubhŒliteral”“”)”}”(hŒ``/proc/<pid>/numa_maps``”h]”hŒ/proc/<pid>/numa_maps”…””}”(hj  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j   hhãubhŒ allows an easy review of where the
pages of a process are located. See also the numa_maps documentation in the
proc(5) man page.”…””}”(hhãhžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h Khh£hžhubh¸)”}”(hX{  Manual migration is useful if for example the scheduler has relocated
a process to a processor on a distant node. A batch scheduler or an
administrator may detect the situation and move the pages of the process
nearer to the new processor. The kernel itself only provides
manual page migration support. Automatic page migration may be implemented
through user space processes that move pages. A special function call
"move_pages" allows the moving of individual pages within a process.
For example, A NUMA profiler may obtain a log showing frequent off-node
accesses and may use the result to move pages to more advantageous
locations.”h]”hX  Manual migration is useful if for example the scheduler has relocated
a process to a processor on a distant node. A batch scheduler or an
administrator may detect the situation and move the pages of the process
nearer to the new processor. The kernel itself only provides
manual page migration support. Automatic page migration may be implemented
through user space processes that move pages. A special function call
â€œmove_pagesâ€ allows the moving of individual pages within a process.
For example, A NUMA profiler may obtain a log showing frequent off-node
accesses and may use the result to move pages to more advantageous
locations.”…””}”(hj  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h Khh£hžhubh¸)”}”(hX  Larger installations usually partition the system using cpusets into
sections of nodes. Paul Jackson has equipped cpusets with the ability to
move pages when a task is moved to another cpuset (See
:ref:`CPUSETS <cpusets>`).
Cpusets allow the automation of process locality. If a task is moved to
a new cpuset then also all its pages are moved with it so that the
performance of the process does not sink dramatically. Also the pages
of processes in a cpuset are moved if the allowed memory nodes of a
cpuset are changed.”h]”(hŒÅLarger installations usually partition the system using cpusets into
sections of nodes. Paul Jackson has equipped cpusets with the ability to
move pages when a task is moved to another cpuset (See
”…””}”(hj(  hžhhŸNh Nubh)”}”(hŒ:ref:`CPUSETS <cpusets>`”h]”hŒinline”“”)”}”(hj2  h]”hŒCPUSETS”…””}”(hj6  hžhhŸNh Nubah}”(h]”h ]”(Œxref”Œstd”Œstd-ref”eh"]”h$]”h&]”uh1j4  hj0  ubah}”(h]”h ]”h"]”h$]”h&]”Œrefdoc”Œmm/page_migration”Œ	refdomain”jA  Œreftype”Œref”Œrefexplicit”ˆŒrefwarn”ˆŒ	reftarget”Œcpusets”uh1hhŸh¶h K*hj(  ubhX+  ).
Cpusets allow the automation of process locality. If a task is moved to
a new cpuset then also all its pages are moved with it so that the
performance of the process does not sink dramatically. Also the pages
of processes in a cpuset are moved if the allowed memory nodes of a
cpuset are changed.”…””}”(hj(  hžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h K*hh£hžhubh¸)”}”(hX\  Page migration allows the preservation of the relative location of pages
within a group of nodes for all migration techniques which will preserve a
particular memory allocation pattern generated even after migrating a
process. This is necessary in order to preserve the memory latencies.
Processes will run with similar performance after migration.”h]”hX\  Page migration allows the preservation of the relative location of pages
within a group of nodes for all migration techniques which will preserve a
particular memory allocation pattern generated even after migrating a
process. This is necessary in order to preserve the memory latencies.
Processes will run with similar performance after migration.”…””}”(hj_  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h K4hh£hžhubh¸)”}”(hX  Page migration occurs in several steps. First a high level
description for those trying to use migrate_pages() from the kernel
(for userspace usage see the Andi Kleen's numactl package mentioned above)
and then a low level description of how the low level details work.”h]”hX  Page migration occurs in several steps. First a high level
description for those trying to use migrate_pages() from the kernel
(for userspace usage see the Andi Kleenâ€™s numactl package mentioned above)
and then a low level description of how the low level details work.”…””}”(hjm  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h K:hh£hžhubh¢)”}”(hhh]”(h§)”}”(hŒ In kernel use of migrate_pages()”h]”hŒ In kernel use of migrate_pages()”…””}”(hj~  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h¦hj{  hžhhŸh¶h K@ubhŒenumerated_list”“”)”}”(hhh]”(hŒ	list_item”“”)”}”(hXq  Remove folios from the LRU.

Lists of folios to be migrated are generated by scanning over
folios and moving them into lists. This is done by
calling folio_isolate_lru().
Calling folio_isolate_lru() increases the references to the folio
so that it cannot vanish while the folio migration occurs.
It also prevents the swapper or other scans from encountering
the folio.
”h]”(h¸)”}”(hŒRemove folios from the LRU.”h]”hŒRemove folios from the LRU.”…””}”(hj—  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h KBhj“  ubh¸)”}”(hXS  Lists of folios to be migrated are generated by scanning over
folios and moving them into lists. This is done by
calling folio_isolate_lru().
Calling folio_isolate_lru() increases the references to the folio
so that it cannot vanish while the folio migration occurs.
It also prevents the swapper or other scans from encountering
the folio.”h]”hXS  Lists of folios to be migrated are generated by scanning over
folios and moving them into lists. This is done by
calling folio_isolate_lru().
Calling folio_isolate_lru() increases the references to the folio
so that it cannot vanish while the folio migration occurs.
It also prevents the swapper or other scans from encountering
the folio.”…””}”(hj¥  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h KDhj“  ubeh}”(h]”h ]”h"]”h$]”h&]”uh1j‘  hjŽ  hžhhŸh¶h Nubj’  )”}”(hŒ±We need to have a function of type new_folio_t that can be
passed to migrate_pages(). This function should figure out
how to allocate the correct new folio given the old folio.
”h]”h¸)”}”(hŒ°We need to have a function of type new_folio_t that can be
passed to migrate_pages(). This function should figure out
how to allocate the correct new folio given the old folio.”h]”hŒ°We need to have a function of type new_folio_t that can be
passed to migrate_pages(). This function should figure out
how to allocate the correct new folio given the old folio.”…””}”(hj½  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h KLhj¹  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j‘  hjŽ  hžhhŸh¶h Nubj’  )”}”(hŒ­The migrate_pages() function is called which attempts
to do the migration. It will call the function to allocate
the new folio for each folio that is considered for moving.
”h]”h¸)”}”(hŒ¬The migrate_pages() function is called which attempts
to do the migration. It will call the function to allocate
the new folio for each folio that is considered for moving.”h]”hŒ¬The migrate_pages() function is called which attempts
to do the migration. It will call the function to allocate
the new folio for each folio that is considered for moving.”…””}”(hjÕ  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h KPhjÑ  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j‘  hjŽ  hžhhŸh¶h Nubeh}”(h]”h ]”h"]”h$]”h&]”Œenumtype”Œarabic”Œprefix”hŒsuffix”Œ.”uh1jŒ  hj{  hžhhŸh¶h KBubeh}”(h]”Œin-kernel-use-of-migrate-pages”ah ]”h"]”Œ in kernel use of migrate_pages()”ah$]”h&]”uh1h¡hh£hžhhŸh¶h K@ubh¢)”}”(hhh]”(h§)”}”(hŒHow migrate_pages() works”h]”hŒHow migrate_pages() works”…””}”(hjÿ  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h¦hjü  hžhhŸh¶h KUubh¸)”}”(hX+  migrate_pages() does several passes over its list of folios. A folio is moved
if all references to a folio are removable at the time. The folio has
already been removed from the LRU via folio_isolate_lru() and the refcount
is increased so that the folio cannot be freed while folio migration occurs.”h]”hX+  migrate_pages() does several passes over its list of folios. A folio is moved
if all references to a folio are removable at the time. The folio has
already been removed from the LRU via folio_isolate_lru() and the refcount
is increased so that the folio cannot be freed while folio migration occurs.”…””}”(hj  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h KWhjü  hžhubh¸)”}”(hŒSteps:”h]”hŒSteps:”…””}”(hj  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h K\hjü  hžhubj  )”}”(hhh]”(j’  )”}”(hŒLock the page to be migrated.
”h]”h¸)”}”(hŒLock the page to be migrated.”h]”hŒLock the page to be migrated.”…””}”(hj0  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h K^hj,  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j‘  hj)  hžhhŸh¶h Nubj’  )”}”(hŒ#Ensure that writeback is complete.
”h]”h¸)”}”(hŒ"Ensure that writeback is complete.”h]”hŒ"Ensure that writeback is complete.”…””}”(hjH  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h K`hjD  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j‘  hj)  hžhhŸh¶h Nubj’  )”}”(hŒœLock the new page that we want to move to. It is locked so that accesses to
this (not yet up-to-date) page immediately block while the move is in progress.
”h]”h¸)”}”(hŒ›Lock the new page that we want to move to. It is locked so that accesses to
this (not yet up-to-date) page immediately block while the move is in progress.”h]”hŒ›Lock the new page that we want to move to. It is locked so that accesses to
this (not yet up-to-date) page immediately block while the move is in progress.”…””}”(hj`  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h Kbhj\  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j‘  hj)  hžhhŸh¶h Nubj’  )”}”(hXN  All the page table references to the page are converted to migration
entries. This decreases the mapcount of a page. If the resulting
mapcount is not zero then we do not migrate the page. All user space
processes that attempt to access the page will now wait on the page lock
or wait for the migration page table entry to be removed.
”h]”h¸)”}”(hXM  All the page table references to the page are converted to migration
entries. This decreases the mapcount of a page. If the resulting
mapcount is not zero then we do not migrate the page. All user space
processes that attempt to access the page will now wait on the page lock
or wait for the migration page table entry to be removed.”h]”hXM  All the page table references to the page are converted to migration
entries. This decreases the mapcount of a page. If the resulting
mapcount is not zero then we do not migrate the page. All user space
processes that attempt to access the page will now wait on the page lock
or wait for the migration page table entry to be removed.”…””}”(hjx  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h Kehjt  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j‘  hj)  hžhhŸh¶h Nubj’  )”}”(hŒ}The i_pages lock is taken. This will cause all processes trying
to access the page via the mapping to block on the spinlock.
”h]”h¸)”}”(hŒ|The i_pages lock is taken. This will cause all processes trying
to access the page via the mapping to block on the spinlock.”h]”hŒ|The i_pages lock is taken. This will cause all processes trying
to access the page via the mapping to block on the spinlock.”…””}”(hj  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h KkhjŒ  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j‘  hj)  hžhhŸh¶h Nubj’  )”}”(hŒŽThe refcount of the page is examined and we back out if references remain.
Otherwise, we know that we are the only one referencing this page.
”h]”h¸)”}”(hŒThe refcount of the page is examined and we back out if references remain.
Otherwise, we know that we are the only one referencing this page.”h]”hŒThe refcount of the page is examined and we back out if references remain.
Otherwise, we know that we are the only one referencing this page.”…””}”(hj¨  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h Knhj¤  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j‘  hj)  hžhhŸh¶h Nubj’  )”}”(hŒThe radix tree is checked and if it does not contain the pointer to this
page then we back out because someone else modified the radix tree.
”h]”h¸)”}”(hŒŒThe radix tree is checked and if it does not contain the pointer to this
page then we back out because someone else modified the radix tree.”h]”hŒŒThe radix tree is checked and if it does not contain the pointer to this
page then we back out because someone else modified the radix tree.”…””}”(hjÀ  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h Kqhj¼  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j‘  hj)  hžhhŸh¶h Nubj’  )”}”(hŒŽThe new page is prepped with some settings from the old page so that
accesses to the new page will discover a page with the correct settings.
”h]”h¸)”}”(hŒThe new page is prepped with some settings from the old page so that
accesses to the new page will discover a page with the correct settings.”h]”hŒThe new page is prepped with some settings from the old page so that
accesses to the new page will discover a page with the correct settings.”…””}”(hjØ  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h KthjÔ  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j‘  hj)  hžhhŸh¶h Nubj’  )”}”(hŒ4The radix tree is changed to point to the new page.
”h]”h¸)”}”(hŒ3The radix tree is changed to point to the new page.”h]”hŒ3The radix tree is changed to point to the new page.”…””}”(hjð  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h Kwhjì  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j‘  hj)  hžhhŸh¶h Nubj’  )”}”(hŒÀThe reference count of the old page is dropped because the address space
reference is gone. A reference to the new page is established because
the new page is referenced by the address space.
”h]”h¸)”}”(hŒ¿The reference count of the old page is dropped because the address space
reference is gone. A reference to the new page is established because
the new page is referenced by the address space.”h]”hŒ¿The reference count of the old page is dropped because the address space
reference is gone. A reference to the new page is established because
the new page is referenced by the address space.”…””}”(hj  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h Kyhj  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j‘  hj)  hžhhŸh¶h Nubj’  )”}”(hŒ§The i_pages lock is dropped. With that lookups in the mapping
become possible again. Processes will move from spinning on the lock
to sleeping on the locked new page.
”h]”h¸)”}”(hŒ¦The i_pages lock is dropped. With that lookups in the mapping
become possible again. Processes will move from spinning on the lock
to sleeping on the locked new page.”h]”hŒ¦The i_pages lock is dropped. With that lookups in the mapping
become possible again. Processes will move from spinning on the lock
to sleeping on the locked new page.”…””}”(hj   hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h K}hj  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j‘  hj)  hžhhŸh¶h Nubj’  )”}”(hŒ.The page contents are copied to the new page.
”h]”h¸)”}”(hŒ-The page contents are copied to the new page.”h]”hŒ-The page contents are copied to the new page.”…””}”(hj8  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h Khj4  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j‘  hj)  hžhhŸh¶h Nubj’  )”}”(hŒ5The remaining page flags are copied to the new page.
”h]”h¸)”}”(hŒ4The remaining page flags are copied to the new page.”h]”hŒ4The remaining page flags are copied to the new page.”…””}”(hjP  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h KƒhjL  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j‘  hj)  hžhhŸh¶h Nubj’  )”}”(hŒcThe old page flags are cleared to indicate that the page does
not provide any information anymore.
”h]”h¸)”}”(hŒbThe old page flags are cleared to indicate that the page does
not provide any information anymore.”h]”hŒbThe old page flags are cleared to indicate that the page does
not provide any information anymore.”…””}”(hjh  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h K…hjd  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j‘  hj)  hžhhŸh¶h Nubj’  )”}”(hŒ2Queued up writeback on the new page is triggered.
”h]”h¸)”}”(hŒ1Queued up writeback on the new page is triggered.”h]”hŒ1Queued up writeback on the new page is triggered.”…””}”(hj€  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h Kˆhj|  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j‘  hj)  hžhhŸh¶h Nubj’  )”}”(hŒ¶If migration entries were inserted into the page table, then replace them
with real ptes. Doing so will enable access for user space processes not
already waiting for the page lock.
”h]”h¸)”}”(hŒµIf migration entries were inserted into the page table, then replace them
with real ptes. Doing so will enable access for user space processes not
already waiting for the page lock.”h]”hŒµIf migration entries were inserted into the page table, then replace them
with real ptes. Doing so will enable access for user space processes not
already waiting for the page lock.”…””}”(hj˜  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h KŠhj”  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j‘  hj)  hžhhŸh¶h Nubj’  )”}”(hŒ’The page locks are dropped from the old and new page.
Processes waiting on the page lock will redo their page faults
and will reach the new page.
”h]”h¸)”}”(hŒ‘The page locks are dropped from the old and new page.
Processes waiting on the page lock will redo their page faults
and will reach the new page.”h]”hŒ‘The page locks are dropped from the old and new page.
Processes waiting on the page lock will redo their page faults
and will reach the new page.”…””}”(hj°  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h KŽhj¬  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j‘  hj)  hžhhŸh¶h Nubj’  )”}”(hŒPThe new page is moved to the LRU and can be scanned by the swapper,
etc. again.
”h]”h¸)”}”(hŒOThe new page is moved to the LRU and can be scanned by the swapper,
etc. again.”h]”hŒOThe new page is moved to the LRU and can be scanned by the swapper,
etc. again.”…””}”(hjÈ  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h K’hjÄ  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j‘  hj)  hžhhŸh¶h Nubeh}”(h]”h ]”h"]”h$]”h&]”jï  jð  jñ  hjò  jó  uh1jŒ  hjü  hžhhŸh¶h K^ubeh}”(h]”Œhow-migrate-pages-works”ah ]”h"]”Œhow migrate_pages() works”ah$]”h&]”uh1h¡hh£hžhhŸh¶h KUubh¢)”}”(hhh]”(h§)”}”(hŒNon-LRU page migration”h]”hŒNon-LRU page migration”…””}”(hjí  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h¦hjê  hžhhŸh¶h K–ubh¸)”}”(hX  Although migration originally aimed for reducing the latency of memory
accesses for NUMA, compaction also uses migration to create high-order
pages.  For compaction purposes, it is also useful to be able to move
non-LRU pages, such as zsmalloc and virtio-balloon pages.”h]”hX  Although migration originally aimed for reducing the latency of memory
accesses for NUMA, compaction also uses migration to create high-order
pages.  For compaction purposes, it is also useful to be able to move
non-LRU pages, such as zsmalloc and virtio-balloon pages.”…””}”(hjû  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h K˜hjê  hžhubh¸)”}”(hX  If a driver wants to make its pages movable, it should define a struct
movable_operations.  It then needs to call __SetPageMovable() on each
page that it may be able to move.  This uses the ``page->mapping`` field,
so this field is not available for the driver to use for other purposes.”h]”(hŒ¾If a driver wants to make its pages movable, it should define a struct
movable_operations.  It then needs to call __SetPageMovable() on each
page that it may be able to move.  This uses the ”…””}”(hj	  hžhhŸNh Nubj  )”}”(hŒ``page->mapping``”h]”hŒpage->mapping”…””}”(hj  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j   hj	  ubhŒP field,
so this field is not available for the driver to use for other purposes.”…””}”(hj	  hžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h Khjê  hžhubeh}”(h]”Œnon-lru-page-migration”ah ]”h"]”Œnon-lru page migration”ah$]”h&]”uh1h¡hh£hžhhŸh¶h K–ubh¢)”}”(hhh]”(h§)”}”(hŒMonitoring Migration”h]”hŒMonitoring Migration”…””}”(hj4  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h¦hj1  hžhhŸh¶h K£ubh¸)”}”(hŒFThe following events (counters) can be used to monitor page migration.”h]”hŒFThe following events (counters) can be used to monitor page migration.”…””}”(hjB  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h K¥hj1  hžhubj  )”}”(hhh]”(j’  )”}”(hXž  PGMIGRATE_SUCCESS: Normal page migration success. Each count means that a
page was migrated. If the page was a non-THP and non-hugetlb page, then
this counter is increased by one. If the page was a THP or hugetlb, then
this counter is increased by the number of THP or hugetlb subpages.
For example, migration of a single 2MB THP that has 4KB-size base pages
(subpages) will cause this counter to increase by 512.
”h]”h¸)”}”(hX  PGMIGRATE_SUCCESS: Normal page migration success. Each count means that a
page was migrated. If the page was a non-THP and non-hugetlb page, then
this counter is increased by one. If the page was a THP or hugetlb, then
this counter is increased by the number of THP or hugetlb subpages.
For example, migration of a single 2MB THP that has 4KB-size base pages
(subpages) will cause this counter to increase by 512.”h]”hX  PGMIGRATE_SUCCESS: Normal page migration success. Each count means that a
page was migrated. If the page was a non-THP and non-hugetlb page, then
this counter is increased by one. If the page was a THP or hugetlb, then
this counter is increased by the number of THP or hugetlb subpages.
For example, migration of a single 2MB THP that has 4KB-size base pages
(subpages) will cause this counter to increase by 512.”…””}”(hjW  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h K§hjS  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j‘  hjP  hžhhŸh¶h Nubj’  )”}”(hŒ²PGMIGRATE_FAIL: Normal page migration failure. Same counting rules as for
PGMIGRATE_SUCCESS, above: this will be increased by the number of subpages,
if it was a THP or hugetlb.
”h]”h¸)”}”(hŒ±PGMIGRATE_FAIL: Normal page migration failure. Same counting rules as for
PGMIGRATE_SUCCESS, above: this will be increased by the number of subpages,
if it was a THP or hugetlb.”h]”hŒ±PGMIGRATE_FAIL: Normal page migration failure. Same counting rules as for
PGMIGRATE_SUCCESS, above: this will be increased by the number of subpages,
if it was a THP or hugetlb.”…””}”(hjo  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h K®hjk  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j‘  hjP  hžhhŸh¶h Nubj’  )”}”(hŒ?THP_MIGRATION_SUCCESS: A THP was migrated without being split.
”h]”h¸)”}”(hŒ>THP_MIGRATION_SUCCESS: A THP was migrated without being split.”h]”hŒ>THP_MIGRATION_SUCCESS: A THP was migrated without being split.”…””}”(hj‡  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h K²hjƒ  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j‘  hjP  hžhhŸh¶h Nubj’  )”}”(hŒGTHP_MIGRATION_FAIL: A THP could not be migrated nor it could be split.
”h]”h¸)”}”(hŒFTHP_MIGRATION_FAIL: A THP could not be migrated nor it could be split.”h]”hŒFTHP_MIGRATION_FAIL: A THP could not be migrated nor it could be split.”…””}”(hjŸ  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h K´hj›  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j‘  hjP  hžhhŸh¶h Nubj’  )”}”(hŒ™THP_MIGRATION_SPLIT: A THP was migrated, but not as such: first, the THP had
to be split. After splitting, a migration retry was used for its sub-pages.
”h]”h¸)”}”(hŒ˜THP_MIGRATION_SPLIT: A THP was migrated, but not as such: first, the THP had
to be split. After splitting, a migration retry was used for its sub-pages.”h]”hŒ˜THP_MIGRATION_SPLIT: A THP was migrated, but not as such: first, the THP had
to be split. After splitting, a migration retry was used for its sub-pages.”…””}”(hj·  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h K¶hj³  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j‘  hjP  hžhhŸh¶h Nubeh}”(h]”h ]”h"]”h$]”h&]”jï  jð  jñ  hjò  jó  uh1jŒ  hj1  hžhhŸh¶h K§ubh¸)”}”(hŒÆTHP_MIGRATION_* events also update the appropriate PGMIGRATE_SUCCESS or
PGMIGRATE_FAIL events. For example, a THP migration failure will cause both
THP_MIGRATION_FAIL and PGMIGRATE_FAIL to increase.”h]”hŒÆTHP_MIGRATION_* events also update the appropriate PGMIGRATE_SUCCESS or
PGMIGRATE_FAIL events. For example, a THP migration failure will cause both
THP_MIGRATION_FAIL and PGMIGRATE_FAIL to increase.”…””}”(hjÑ  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h K¹hj1  hžhubh¸)”}”(hŒ:Christoph Lameter, May 8, 2006.
Minchan Kim, Mar 28, 2016.”h]”hŒ:Christoph Lameter, May 8, 2006.
Minchan Kim, Mar 28, 2016.”…””}”(hjß  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h K½hj1  hžhubh Œindex”“”)”}”(hhh]”h}”(h]”h ]”h"]”h$]”h&]”Œentries”]”(Œsingle”Œmovable_operations (C struct)”Œc.movable_operations”hNt”auh1jí  hj1  hžhhŸNh Nubh Œdesc”“”)”}”(hhh]”(h Œdesc_signature”“”)”}”(hŒmovable_operations”h]”h Œdesc_signature_line”“”)”}”(hŒstruct movable_operations”h]”(h Œdesc_sig_keyword”“”)”}”(hŒstruct”h]”hŒstruct”…””}”(hj  hžhhŸNh Nubah}”(h]”h ]”Œk”ah"]”h$]”h&]”uh1j  hj  hžhhŸŒZ/var/lib/git/docbuild/linux/Documentation/mm/page_migration:192: ./include/linux/migrate.h”h Kubh Œdesc_sig_space”“”)”}”(hŒ ”h]”hŒ ”…””}”(hj#  hžhhŸNh Nubah}”(h]”h ]”Œw”ah"]”h$]”h&]”uh1j!  hj  hžhhŸj   h Kubh Œ	desc_name”“”)”}”(hŒmovable_operations”h]”h Œdesc_sig_name”“”)”}”(hj  h]”hŒmovable_operations”…””}”(hj:  hžhhŸNh Nubah}”(h]”h ]”Œn”ah"]”h$]”h&]”uh1j8  hj4  ubah}”(h]”h ]”(Œsig-name”Œdescname”eh"]”h$]”h&]”Œ	xml:space”Œpreserve”uh1j2  hj  hžhhŸj   h Kubeh}”(h]”h ]”h"]”h$]”h&]”jP  jQ  Œadd_permalink”ˆuh1j	  Œsphinx_line_type”Œ
declarator”hj  hžhhŸj   h Kubah}”(h]”jü  ah ]”(Œsig”Œ
sig-object”eh"]”h$]”h&]”Œis_multiline”ˆŒ
_toc_parts”)Œ	_toc_name”huh1j  hŸj   h Khj   hžhubh Œdesc_content”“”)”}”(hhh]”h¸)”}”(hŒDriver page migration”h]”hŒDriver page migration”…””}”(hjk  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸŒZ/var/lib/git/docbuild/linux/Documentation/mm/page_migration:192: ./include/linux/migrate.h”h Khjh  hžhubah}”(h]”h ]”h"]”h$]”h&]”uh1jf  hj   hžhhŸj   h Kubeh}”(h]”h ]”(Œc”Œstruct”eh"]”h$]”h&]”Œdomain”jƒ  Œobjtype”j„  Œdesctype”j„  Œnoindex”‰Œnoindexentry”‰Œnocontentsentry”‰uh1jþ  hžhhj1  hŸNh NubhŒ	container”“”)”}”(hXY  **Definition**::

  struct movable_operations {
      bool (*isolate_page)(struct page *, isolate_mode_t);
      int (*migrate_page)(struct page *dst, struct page *src, enum migrate_mode);
      void (*putback_page)(struct page *);
  };

**Members**

``isolate_page``
  The VM calls this function to prepare the page to be moved.  The page
  is locked and the driver should not unlock it.  The driver should
  return ``true`` if the page is movable and ``false`` if it is not
  currently movable.  After this function returns, the VM uses the
  page->lru field, so the driver must preserve any information which
  is usually stored here.

``migrate_page``
  After isolation, the VM calls this function with the isolated
  **src** page.  The driver should copy the contents of the
  **src** page to the **dst** page and set up the fields of **dst** page.
  Both pages are locked.
  If page migration is successful, the driver should call
  __ClearPageMovable(**src**) and return MIGRATEPAGE_SUCCESS.
  If the driver cannot migrate the page at the moment, it can return
  -EAGAIN.  The VM interprets this as a temporary migration failure and
  will retry it later.  Any other error value is a permanent migration
  failure and migration will not be retried.
  The driver shouldn't touch the **src->lru** field while in the
  migrate_page() function.  It may write to **dst->lru**.

``putback_page``
  If migration fails on the isolated page, the VM informs the driver
  that the page is no longer a candidate for migration by calling
  this function.  The driver should put the isolated page back into
  its own data structure.”h]”(h¸)”}”(hŒ**Definition**::”h]”(hŒstrong”“”)”}”(hŒ**Definition**”h]”hŒ
Definition”…””}”(hjš  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j˜  hj”  ubhŒ:”…””}”(hj”  hžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸŒZ/var/lib/git/docbuild/linux/Documentation/mm/page_migration:192: ./include/linux/migrate.h”h Khj  ubhŒliteral_block”“”)”}”(hŒÐstruct movable_operations {
    bool (*isolate_page)(struct page *, isolate_mode_t);
    int (*migrate_page)(struct page *dst, struct page *src, enum migrate_mode);
    void (*putback_page)(struct page *);
};”h]”hŒÐstruct movable_operations {
    bool (*isolate_page)(struct page *, isolate_mode_t);
    int (*migrate_page)(struct page *dst, struct page *src, enum migrate_mode);
    void (*putback_page)(struct page *);
};”…””}”hjµ  sbah}”(h]”h ]”h"]”h$]”h&]”jP  jQ  uh1j³  hŸŒZ/var/lib/git/docbuild/linux/Documentation/mm/page_migration:192: ./include/linux/migrate.h”h Khj  ubh¸)”}”(hŒ**Members**”h]”j™  )”}”(hjÆ  h]”hŒMembers”…””}”(hjÈ  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j˜  hjÄ  ubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸŒZ/var/lib/git/docbuild/linux/Documentation/mm/page_migration:192: ./include/linux/migrate.h”h K$hj  ubhŒdefinition_list”“”)”}”(hhh]”(hŒdefinition_list_item”“”)”}”(hXw  ``isolate_page``
The VM calls this function to prepare the page to be moved.  The page
is locked and the driver should not unlock it.  The driver should
return ``true`` if the page is movable and ``false`` if it is not
currently movable.  After this function returns, the VM uses the
page->lru field, so the driver must preserve any information which
is usually stored here.
”h]”(hŒterm”“”)”}”(hŒ``isolate_page``”h]”j  )”}”(hjë  h]”hŒisolate_page”…””}”(hjí  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j   hjé  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jç  hŸŒZ/var/lib/git/docbuild/linux/Documentation/mm/page_migration:192: ./include/linux/migrate.h”h Khjã  ubhŒ
definition”“”)”}”(hhh]”h¸)”}”(hXe  The VM calls this function to prepare the page to be moved.  The page
is locked and the driver should not unlock it.  The driver should
return ``true`` if the page is movable and ``false`` if it is not
currently movable.  After this function returns, the VM uses the
page->lru field, so the driver must preserve any information which
is usually stored here.”h]”(hŒThe VM calls this function to prepare the page to be moved.  The page
is locked and the driver should not unlock it.  The driver should
return ”…””}”(hj  hžhhŸNh Nubj  )”}”(hŒ``true``”h]”hŒtrue”…””}”(hj  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j   hj  ubhŒ if the page is movable and ”…””}”(hj  hžhhŸNh Nubj  )”}”(hŒ	``false``”h]”hŒfalse”…””}”(hj   hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j   hj  ubhŒ© if it is not
currently movable.  After this function returns, the VM uses the
page->lru field, so the driver must preserve any information which
is usually stored here.”…””}”(hj  hžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸŒZ/var/lib/git/docbuild/linux/Documentation/mm/page_migration:192: ./include/linux/migrate.h”h Khj  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j  hjã  ubeh}”(h]”h ]”h"]”h$]”h&]”uh1já  hŸj   h KhjÞ  ubjâ  )”}”(hXÌ  ``migrate_page``
After isolation, the VM calls this function with the isolated
**src** page.  The driver should copy the contents of the
**src** page to the **dst** page and set up the fields of **dst** page.
Both pages are locked.
If page migration is successful, the driver should call
__ClearPageMovable(**src**) and return MIGRATEPAGE_SUCCESS.
If the driver cannot migrate the page at the moment, it can return
-EAGAIN.  The VM interprets this as a temporary migration failure and
will retry it later.  Any other error value is a permanent migration
failure and migration will not be retried.
The driver shouldn't touch the **src->lru** field while in the
migrate_page() function.  It may write to **dst->lru**.
”h]”(jè  )”}”(hŒ``migrate_page``”h]”j  )”}”(hjK  h]”hŒmigrate_page”…””}”(hjM  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j   hjI  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jç  hŸŒZ/var/lib/git/docbuild/linux/Documentation/mm/page_migration:192: ./include/linux/migrate.h”h K-hjE  ubj  )”}”(hhh]”h¸)”}”(hXº  After isolation, the VM calls this function with the isolated
**src** page.  The driver should copy the contents of the
**src** page to the **dst** page and set up the fields of **dst** page.
Both pages are locked.
If page migration is successful, the driver should call
__ClearPageMovable(**src**) and return MIGRATEPAGE_SUCCESS.
If the driver cannot migrate the page at the moment, it can return
-EAGAIN.  The VM interprets this as a temporary migration failure and
will retry it later.  Any other error value is a permanent migration
failure and migration will not be retried.
The driver shouldn't touch the **src->lru** field while in the
migrate_page() function.  It may write to **dst->lru**.”h]”(hŒ>After isolation, the VM calls this function with the isolated
”…””}”(hjd  hžhhŸNh Nubj™  )”}”(hŒ**src**”h]”hŒsrc”…””}”(hjl  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j˜  hjd  ubhŒ3 page.  The driver should copy the contents of the
”…””}”(hjd  hžhhŸNh Nubj™  )”}”(hŒ**src**”h]”hŒsrc”…””}”(hj~  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j˜  hjd  ubhŒ page to the ”…””}”(hjd  hžhhŸNh Nubj™  )”}”(hŒ**dst**”h]”hŒdst”…””}”(hj  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j˜  hjd  ubhŒ page and set up the fields of ”…””}”(hjd  hžhhŸNh Nubj™  )”}”(hŒ**dst**”h]”hŒdst”…””}”(hj¢  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j˜  hjd  ubhŒi page.
Both pages are locked.
If page migration is successful, the driver should call
__ClearPageMovable(”…””}”(hjd  hžhhŸNh Nubj™  )”}”(hŒ**src**”h]”hŒsrc”…””}”(hj´  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j˜  hjd  ubhX<  ) and return MIGRATEPAGE_SUCCESS.
If the driver cannot migrate the page at the moment, it can return
-EAGAIN.  The VM interprets this as a temporary migration failure and
will retry it later.  Any other error value is a permanent migration
failure and migration will not be retried.
The driver shouldnâ€™t touch the ”…””}”(hjd  hžhhŸNh Nubj™  )”}”(hŒ**src->lru**”h]”hŒsrc->lru”…””}”(hjÆ  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j˜  hjd  ubhŒ> field while in the
migrate_page() function.  It may write to ”…””}”(hjd  hžhhŸNh Nubj™  )”}”(hŒ**dst->lru**”h]”hŒdst->lru”…””}”(hjØ  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j˜  hjd  ubhŒ.”…””}”(hjd  hžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸŒZ/var/lib/git/docbuild/linux/Documentation/mm/page_migration:192: ./include/linux/migrate.h”h K"hja  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j  hjE  ubeh}”(h]”h ]”h"]”h$]”h&]”uh1já  hŸj`  h K-hjÞ  ubjâ  )”}”(hŒí``putback_page``
If migration fails on the isolated page, the VM informs the driver
that the page is no longer a candidate for migration by calling
this function.  The driver should put the isolated page back into
its own data structure.”h]”(jè  )”}”(hŒ``putback_page``”h]”j  )”}”(hj  h]”hŒputback_page”…””}”(hj  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j   hj  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jç  hŸŒZ/var/lib/git/docbuild/linux/Documentation/mm/page_migration:192: ./include/linux/migrate.h”h K2hjý  ubj  )”}”(hhh]”h¸)”}”(hŒÜIf migration fails on the isolated page, the VM informs the driver
that the page is no longer a candidate for migration by calling
this function.  The driver should put the isolated page back into
its own data structure.”h]”hŒÜIf migration fails on the isolated page, the VM informs the driver
that the page is no longer a candidate for migration by calling
this function.  The driver should put the isolated page back into
its own data structure.”…””}”(hj  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸŒZ/var/lib/git/docbuild/linux/Documentation/mm/page_migration:192: ./include/linux/migrate.h”h K0hj  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j  hjý  ubeh}”(h]”h ]”h"]”h$]”h&]”uh1já  hŸj  h K2hjÞ  ubeh}”(h]”h ]”h"]”h$]”h&]”uh1jÜ  hj  ubeh}”(h]”h ]”Œkernelindent”ah"]”h$]”h&]”uh1jŽ  hj1  hžhhŸNh Nubeh}”(h]”Œmonitoring-migration”ah ]”h"]”Œmonitoring migration”ah$]”h&]”uh1h¡hh£hžhhŸh¶h K£ubeh}”(h]”Œpage-migration”ah ]”h"]”Œpage migration”ah$]”h&]”uh1h¡hhhžhhŸh¶h Kubeh}”(h]”h ]”h"]”h$]”h&]”Œsource”h¶uh1hŒcurrent_source”NŒcurrent_line”NŒsettings”Œdocutils.frontend”ŒValues”“”)”}”(h¦NŒ	generator”NŒ	datestamp”NŒsource_link”NŒ
source_url”NŒtoc_backlinks”Œentry”Œfootnote_backlinks”KŒsectnum_xform”KŒstrip_comments”NŒstrip_elements_with_classes”NŒstrip_classes”NŒreport_level”KŒ
halt_level”KŒexit_status_level”KŒdebug”NŒwarning_stream”NŒ	traceback”ˆŒinput_encoding”Œ	utf-8-sig”Œinput_encoding_error_handler”Œstrict”Œoutput_encoding”Œutf-8”Œoutput_encoding_error_handler”jw  Œerror_encoding”Œutf-8”Œerror_encoding_error_handler”Œbackslashreplace”Œlanguage_code”Œen”Œrecord_dependencies”NŒconfig”NŒ	id_prefix”hŒauto_id_prefix”Œid”Œdump_settings”NŒdump_internals”NŒdump_transforms”NŒdump_pseudo_xml”NŒexpose_internals”NŒstrict_visitor”NŒ_disable_config”NŒ_source”h¶Œ_destination”NŒ_config_files”]”Œ7/var/lib/git/docbuild/linux/Documentation/docutils.conf”aŒfile_insertion_enabled”ˆŒraw_enabled”KŒline_length_limit”M'Œpep_references”NŒpep_base_url”Œhttps://peps.python.org/”Œpep_file_url_template”Œpep-%04d”Œrfc_references”NŒrfc_base_url”Œ&https://datatracker.ietf.org/doc/html/”Œ	tab_width”KŒtrim_footnote_reference_space”‰Œsyntax_highlight”Œlong”Œsmart_quotes”ˆŒsmartquotes_locales”]”Œcharacter_level_inline_markup”‰Œdoctitle_xform”‰Œdocinfo_xform”KŒsectsubtitle_xform”‰Œimage_loading”Œlink”Œembed_stylesheet”‰Œcloak_email_addresses”ˆŒsection_self_link”‰Œenv”NubŒreporter”NŒindirect_targets”]”Œsubstitution_defs”}”Œsubstitution_names”}”Œrefnames”}”Œrefids”}”Œnameids”}”(jQ  jN  jù  jö  jç  jä  j.  j+  jI  jF  uŒ	nametypes”}”(jQ  ‰jù  ‰jç  ‰j.  ‰jI  ‰uh}”(jN  h£jö  j{  jä  jü  j+  jê  jF  j1  jü  j  uŒfootnote_refs”}”Œcitation_refs”}”Œautofootnotes”]”Œautofootnote_refs”]”Œsymbol_footnotes”]”Œsymbol_footnote_refs”]”Œ	footnotes”]”Œ	citations”]”Œautofootnote_start”KŒsymbol_footnote_start”K Œ
id_counter”Œcollections”ŒCounter”“”}”…”R”Œparse_messages”]”Œtransform_messages”]”Œtransformer”NŒinclude_log”]”Œ
decoration”Nhžhub.