sphinx.addnodesdocument)}( rawsource children]( translations
LanguagesNode)}(hhh](h pending_xref)}(hhh]docutils.nodesTextChinese (Simplified)}parenthsba
attributes}(ids]classes]names]dupnames]backrefs] refdomainstdreftypedoc reftarget//translations/zh_CN/admin-guide/pm/sleep-statesmodnameN classnameN refexplicitutagnamehhh ubh)}(hhh]hChinese (Traditional)}hh2sbah }(h ]h ]h"]h$]h&] refdomainh)reftypeh+ reftarget//translations/zh_TW/admin-guide/pm/sleep-statesmodnameN classnameN refexplicituh1hhh ubh)}(hhh]hItalian}hhFsbah }(h ]h ]h"]h$]h&] refdomainh)reftypeh+ reftarget//translations/it_IT/admin-guide/pm/sleep-statesmodnameN classnameN refexplicituh1hhh ubh)}(hhh]hJapanese}hhZsbah }(h ]h ]h"]h$]h&] refdomainh)reftypeh+ reftarget//translations/ja_JP/admin-guide/pm/sleep-statesmodnameN classnameN refexplicituh1hhh ubh)}(hhh]hKorean}hhnsbah }(h ]h ]h"]h$]h&] refdomainh)reftypeh+ reftarget//translations/ko_KR/admin-guide/pm/sleep-statesmodnameN classnameN refexplicituh1hhh ubh)}(hhh]hPortuguese (Brazilian)}hhsbah }(h ]h ]h"]h$]h&] refdomainh)reftypeh+ reftarget//translations/pt_BR/admin-guide/pm/sleep-statesmodnameN classnameN refexplicituh1hhh ubh)}(hhh]hSpanish}hhsbah }(h ]h ]h"]h$]h&] refdomainh)reftypeh+ reftarget//translations/sp_SP/admin-guide/pm/sleep-statesmodnameN classnameN refexplicituh1hhh ubeh }(h ]h ]h"]h$]h&]current_languageEnglishuh1h
hh _documenthsourceNlineNubhcomment)}(h SPDX-License-Identifier: GPL-2.0h]h SPDX-License-Identifier: GPL-2.0}hhsbah }(h ]h ]h"]h$]h&] xml:spacepreserveuh1hhhhhhI/var/lib/git/docbuild/linux/Documentation/admin-guide/pm/sleep-states.rsthKubh)}(h4This data file has been placed in the public domain.h]h4This data file has been placed in the public domain.}hhsbah }(h ]h ]h"]h$]h&]hhuh1hhhhhho/srv/docbuild/lib/venvs/build-kernel-docs/lib64/python3.9/site-packages/docutils/parsers/rst/include/isonum.txthKubh)}(hDerived from the Unicode character mappings available from
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Processed by unicode2rstsubs.py, part of Docutils:
.h]hDerived from the Unicode character mappings available from
.
Processed by unicode2rstsubs.py, part of Docutils:
.}hhsbah }(h ]h ]h"]h$]h&]hhuh1hhhhhhhhKubhsubstitution_definition)}(h*.. |amp| unicode:: U+00026 .. AMPERSANDh]h&}hhsbah }(h ]h ]h"]ampah$]h&]uh1hhhhKhhhhubh)}(h+.. |apos| unicode:: U+00027 .. APOSTROPHEh]h'}hhsbah }(h ]h ]h"]aposah$]h&]uh1hhhhKhhhhubh)}(h).. |ast| unicode:: U+0002A .. ASTERISKh]h*}hj sbah }(h ]h ]h"]astah$]h&]uh1hhhhK hhhhubh)}(h+.. |brvbar| unicode:: U+000A6 .. BROKEN BARh]h¦}hj sbah }(h ]h ]h"]brvbarah$]h&]uh1hhhhK
hhhhubh)}(h0.. |bsol| unicode:: U+0005C .. REVERSE SOLIDUSh]h\}hj# sbah }(h ]h ]h"]bsolah$]h&]uh1hhhhK hhhhubh)}(h*.. |cent| unicode:: U+000A2 .. CENT SIGNh]h¢}hj2 sbah }(h ]h ]h"]centah$]h&]uh1hhhhK hhhhubh)}(h&.. |colon| unicode:: U+0003A .. COLONh]h:}hjA sbah }(h ]h ]h"]colonah$]h&]uh1hhhhK
hhhhubh)}(h&.. |comma| unicode:: U+0002C .. COMMAh]h,}hjP sbah }(h ]h ]h"]commaah$]h&]uh1hhhhKhhhhubh)}(h... |commat| unicode:: U+00040 .. COMMERCIAL ATh]h@}hj_ sbah }(h ]h ]h"]commatah$]h&]uh1hhhhKhhhhubh)}(h/.. |copy| unicode:: U+000A9 .. COPYRIGHT SIGNh]h©}hjn sbah }(h ]h ]h"]copyah$]h&]uh1hhhhKhhhhubh)}(h... |curren| unicode:: U+000A4 .. CURRENCY SIGNh]h¤}hj} sbah }(h ]h ]h"]currenah$]h&]uh1hhhhKhhhhubh)}(h0.. |darr| unicode:: U+02193 .. DOWNWARDS ARROWh]h↓}hj sbah }(h ]h ]h"]darrah$]h&]uh1hhhhKhhhhubh)}(h,.. |deg| unicode:: U+000B0 .. DEGREE SIGNh]h°}hj sbah }(h ]h ]h"]degah$]h&]uh1hhhhKhhhhubh)}(h... |divide| unicode:: U+000F7 .. DIVISION SIGNh]h÷}hj sbah }(h ]h ]h"]divideah$]h&]uh1hhhhKhhhhubh)}(h,.. |dollar| unicode:: U+00024 .. DOLLAR SIGNh]h$}hj sbah }(h ]h ]h"]dollarah$]h&]uh1hhhhKhhhhubh)}(h,.. |equals| unicode:: U+0003D .. EQUALS SIGNh]h=}hj sbah }(h ]h ]h"]equalsah$]h&]uh1hhhhKhhhhubh)}(h1.. |excl| unicode:: U+00021 .. EXCLAMATION MARKh]h!}hj sbah }(h ]h ]h"]exclah$]h&]uh1hhhhKhhhhubh)}(h9.. |frac12| unicode:: U+000BD .. VULGAR FRACTION ONE HALFh]h½}hj sbah }(h ]h ]h"]frac12ah$]h&]uh1hhhhKhhhhubh)}(h<.. |frac14| unicode:: U+000BC .. VULGAR FRACTION ONE QUARTERh]h¼}hj sbah }(h ]h ]h"]frac14ah$]h&]uh1hhhhKhhhhubh)}(h;.. |frac18| unicode:: U+0215B .. VULGAR FRACTION ONE EIGHTHh]h⅛}hj sbah }(h ]h ]h"]frac18ah$]h&]uh1hhhhKhhhhubh)}(h?.. |frac34| unicode:: U+000BE .. VULGAR FRACTION THREE QUARTERSh]h¾}hj sbah }(h ]h ]h"]frac34ah$]h&]uh1hhhhKhhhhubh)}(h>.. |frac38| unicode:: U+0215C .. VULGAR FRACTION THREE EIGHTHSh]h⅜}hj" sbah }(h ]h ]h"]frac38ah$]h&]uh1hhhhK hhhhubh)}(h=.. |frac58| unicode:: U+0215D .. VULGAR FRACTION FIVE EIGHTHSh]h⅝}hj1 sbah }(h ]h ]h"]frac58ah$]h&]uh1hhhhK hhhhubh)}(h>.. |frac78| unicode:: U+0215E .. VULGAR FRACTION SEVEN EIGHTHSh]h⅞}hj@ sbah }(h ]h ]h"]frac78ah$]h&]uh1hhhhK hhhhubh)}(h2.. |gt| unicode:: U+0003E .. GREATER-THAN SIGNh]h>}hjO sbah }(h ]h ]h"]gtah$]h&]uh1hhhhK hhhhubh)}(h9.. |half| unicode:: U+000BD .. VULGAR FRACTION ONE HALFh]h½}hj^ sbah }(h ]h ]h"]halfah$]h&]uh1hhhhK hhhhubh)}(h/.. |horbar| unicode:: U+02015 .. HORIZONTAL BARh]h―}hjm sbah }(h ]h ]h"]horbarah$]h&]uh1hhhhK!hhhhubh)}(h'.. |hyphen| unicode:: U+02010 .. HYPHENh]h‐}hj| sbah }(h ]h ]h"]hyphenah$]h&]uh1hhhhK"hhhhubh)}(h:.. |iexcl| unicode:: U+000A1 .. INVERTED EXCLAMATION MARKh]h¡}hj sbah }(h ]h ]h"]iexclah$]h&]uh1hhhhK#hhhhubh)}(h7.. |iquest| unicode:: U+000BF .. INVERTED QUESTION MARKh]h¿}hj sbah }(h ]h ]h"]iquestah$]h&]uh1hhhhK$hhhhubh)}(hJ.. |laquo| unicode:: U+000AB .. LEFT-POINTING DOUBLE ANGLE QUOTATION MARKh]h«}hj sbah }(h ]h ]h"]laquoah$]h&]uh1hhhhK%hhhhubh)}(h0.. |larr| unicode:: U+02190 .. LEFTWARDS ARROWh]h←}hj sbah }(h ]h ]h"]larrah$]h&]uh1hhhhK&hhhhubh)}(h3.. |lcub| unicode:: U+0007B .. LEFT CURLY BRACKETh]h{}hj sbah }(h ]h ]h"]lcubah$]h&]uh1hhhhK'hhhhubh)}(h;.. |ldquo| unicode:: U+0201C .. LEFT DOUBLE QUOTATION MARKh]h“}hj sbah }(h ]h ]h"]ldquoah$]h&]uh1hhhhK(hhhhubh)}(h).. |lowbar| unicode:: U+0005F .. LOW LINEh]h_}hj sbah }(h ]h ]h"]lowbarah$]h&]uh1hhhhK)hhhhubh)}(h1.. |lpar| unicode:: U+00028 .. LEFT PARENTHESISh]h(}hj sbah }(h ]h ]h"]lparah$]h&]uh1hhhhK*hhhhubh)}(h4.. |lsqb| unicode:: U+0005B .. LEFT SQUARE BRACKETh]h[}hj sbah }(h ]h ]h"]lsqbah$]h&]uh1hhhhK+hhhhubh)}(h;.. |lsquo| unicode:: U+02018 .. LEFT SINGLE QUOTATION MARKh]h‘}hj sbah }(h ]h ]h"]lsquoah$]h&]uh1hhhhK,hhhhubh)}(h/.. |lt| unicode:: U+0003C .. LESS-THAN SIGNh]h<}hj! sbah }(h ]h ]h"]ltah$]h&]uh1hhhhK-hhhhubh)}(h+.. |micro| unicode:: U+000B5 .. MICRO SIGNh]hµ}hj0 sbah }(h ]h ]h"]microah$]h&]uh1hhhhK.hhhhubh)}(h+.. |middot| unicode:: U+000B7 .. MIDDLE DOTh]h·}hj? sbah }(h ]h ]h"]middotah$]h&]uh1hhhhK/hhhhubh)}(h/.. |nbsp| unicode:: U+000A0 .. NO-BREAK SPACEh]h }hjN sbah }(h ]h ]h"]nbspah$]h&]uh1hhhhK0hhhhubh)}(h).. |not| unicode:: U+000AC .. NOT SIGNh]h¬}hj] sbah }(h ]h ]h"]notah$]h&]uh1hhhhK1hhhhubh)}(h,.. |num| unicode:: U+00023 .. NUMBER SIGNh]h#}hjl sbah }(h ]h ]h"]numah$]h&]uh1hhhhK2hhhhubh)}(h).. |ohm| unicode:: U+02126 .. OHM SIGNh]hΩ}hj{ sbah }(h ]h ]h"]ohmah$]h&]uh1hhhhK3hhhhubh)}(h;.. |ordf| unicode:: U+000AA .. FEMININE ORDINAL INDICATORh]hª}hj sbah }(h ]h ]h"]ordfah$]h&]uh1hhhhK4hhhhubh)}(h<.. |ordm| unicode:: U+000BA .. MASCULINE ORDINAL INDICATORh]hº}hj sbah }(h ]h ]h"]ordmah$]h&]uh1hhhhK5hhhhubh)}(h-.. |para| unicode:: U+000B6 .. PILCROW SIGNh]h¶}hj sbah }(h ]h ]h"]paraah$]h&]uh1hhhhK6hhhhubh)}(h-.. |percnt| unicode:: U+00025 .. PERCENT SIGNh]h%}hj sbah }(h ]h ]h"]percntah$]h&]uh1hhhhK7hhhhubh)}(h*.. |period| unicode:: U+0002E .. FULL STOPh]h.}hj sbah }(h ]h ]h"]periodah$]h&]uh1hhhhK8hhhhubh)}(h*.. |plus| unicode:: U+0002B .. PLUS SIGNh]h+}hj sbah }(h ]h ]h"]plusah$]h&]uh1hhhhK9hhhhubh)}(h0.. |plusmn| unicode:: U+000B1 .. PLUS-MINUS SIGNh]h±}hj sbah }(h ]h ]h"]plusmnah$]h&]uh1hhhhK:hhhhubh)}(h+.. |pound| unicode:: U+000A3 .. POUND SIGNh]h£}hj sbah }(h ]h ]h"]poundah$]h&]uh1hhhhK;hhhhubh)}(h... |quest| unicode:: U+0003F .. QUESTION MARKh]h?}hj sbah }(h ]h ]h"]questah$]h&]uh1hhhhKhhhhubh)}(h1.. |rarr| unicode:: U+02192 .. RIGHTWARDS ARROWh]h→}hj/ sbah }(h ]h ]h"]rarrah$]h&]uh1hhhhK?hhhhubh)}(h4.. |rcub| unicode:: U+0007D .. RIGHT CURLY BRACKETh]h}}hj> sbah }(h ]h ]h"]rcubah$]h&]uh1hhhhK@hhhhubh)}(h<.. |rdquo| unicode:: U+0201D .. RIGHT DOUBLE QUOTATION MARKh]h”}hjM sbah }(h ]h ]h"]rdquoah$]h&]uh1hhhhKAhhhhubh)}(h0.. |reg| unicode:: U+000AE .. REGISTERED SIGNh]h®}hj\ sbah }(h ]h ]h"]regah$]h&]uh1hhhhKBhhhhubh)}(h2.. |rpar| unicode:: U+00029 .. RIGHT PARENTHESISh]h)}hjk sbah }(h ]h ]h"]rparah$]h&]uh1hhhhKChhhhubh)}(h5.. |rsqb| unicode:: U+0005D .. RIGHT SQUARE BRACKETh]h]}hjz sbah }(h ]h ]h"]rsqbah$]h&]uh1hhhhKDhhhhubh)}(h<.. |rsquo| unicode:: U+02019 .. RIGHT SINGLE QUOTATION MARKh]h’}hj sbah }(h ]h ]h"]rsquoah$]h&]uh1hhhhKEhhhhubh)}(h-.. |sect| unicode:: U+000A7 .. SECTION SIGNh]h§}hj sbah }(h ]h ]h"]sectah$]h&]uh1hhhhKFhhhhubh)}(h*.. |semi| unicode:: U+0003B .. SEMICOLONh]h;}hj sbah }(h ]h ]h"]semiah$]h&]uh1hhhhKGhhhhubh)}(h,.. |shy| unicode:: U+000AD .. SOFT HYPHENh]h}hj sbah }(h ]h ]h"]shyah$]h&]uh1hhhhKHhhhhubh)}(h(.. |sol| unicode:: U+0002F .. SOLIDUSh]h/}hj sbah }(h ]h ]h"]solah$]h&]uh1hhhhKIhhhhubh)}(h,.. |sung| unicode:: U+0266A .. EIGHTH NOTEh]h♪}hj sbah }(h ]h ]h"]sungah$]h&]uh1hhhhKJhhhhubh)}(h0.. |sup1| unicode:: U+000B9 .. SUPERSCRIPT ONEh]h¹}hj sbah }(h ]h ]h"]sup1ah$]h&]uh1hhhhKKhhhhubh)}(h0.. |sup2| unicode:: U+000B2 .. SUPERSCRIPT TWOh]h²}hj sbah }(h ]h ]h"]sup2ah$]h&]uh1hhhhKLhhhhubh)}(h2.. |sup3| unicode:: U+000B3 .. SUPERSCRIPT THREEh]h³}hj sbah }(h ]h ]h"]sup3ah$]h&]uh1hhhhKMhhhhubh)}(h4.. |times| unicode:: U+000D7 .. MULTIPLICATION SIGNh]h×}hj sbah }(h ]h ]h"]timesah$]h&]uh1hhhhKNhhhhubh)}(h0.. |trade| unicode:: U+02122 .. TRADE MARK SIGNh]h™}hj sbah }(h ]h ]h"]tradeah$]h&]uh1hhhhKOhhhhubh)}(h... |uarr| unicode:: U+02191 .. UPWARDS ARROWh]h↑}hj. sbah }(h ]h ]h"]uarrah$]h&]uh1hhhhKPhhhhubh)}(h... |verbar| unicode:: U+0007C .. VERTICAL LINEh]h|}hj= sbah }(h ]h ]h"]verbarah$]h&]uh1hhhhKQhhhhubh)}(h*.. |yen| unicode:: U+000A5 .. YEN SIGN
h]h¥}hjL sbah }(h ]h ]h"]yenah$]h&]uh1hhhhKRhhhhubhsection)}(hhh](htitle)}(hSystem Sleep Statesh]hSystem Sleep States}(hjb hhhNhNubah }(h ]h ]h"]h$]h&]uh1j` hj] hhhhhKubh
field_list)}(hhh](hfield)}(hhh](h
field_name)}(h Copyrighth]h Copyright}(hj| hhhNhNubah }(h ]h ]h"]h$]h&]uh1jz hjw hhhK ubh
field_body)}(h |copy| 2017 Intel Corporation
h]h paragraph)}(h |copy| 2017 Intel Corporationh](h©}(hj hhhNhNubh 2017 Intel Corporation}(hj hhhNhNubeh }(h ]h ]h"]h$]h&]uh1j hhhKhj ubah }(h ]h ]h"]h$]h&]uh1j hjw ubeh }(h ]h ]h"]h$]h&]uh1ju hhhKhjr hhubjv )}(hhh](j{ )}(hAuthorh]hAuthor}(hj hhhNhNubah }(h ]h ]h"]h$]h&]uh1jz hj hhhK ubj )}(h0Rafael J. Wysocki
h]j )}(h.Rafael J. Wysocki h](hRafael J. Wysocki <}(hj hhhNhNubh reference)}(hrafael.j.wysocki@intel.comh]hrafael.j.wysocki@intel.com}(hj hhhNhNubah }(h ]h ]h"]h$]h&]refuri!mailto:rafael.j.wysocki@intel.comuh1j hj ubh>}(hj hhhNhNubeh }(h ]h ]h"]h$]h&]uh1j hhhK
hj ubah }(h ]h ]h"]h$]h&]uh1j hj ubeh }(h ]h ]h"]h$]h&]uh1ju hhhK
hjr hhubeh }(h ]h ]h"]h$]h&]uh1jp hj] hhhhhKubj )}(hSleep states are global low-power states of the entire system in which user
space code cannot be executed and the overall system activity is significantly
reduced.h]hSleep states are global low-power states of the entire system in which user
space code cannot be executed and the overall system activity is significantly
reduced.}(hj hhhNhNubah }(h ]h ]h"]h$]h&]uh1j hhhK
hj] hhubj\ )}(hhh](ja )}(h"Sleep States That Can Be Supportedh]h"Sleep States That Can Be Supported}(hj hhhNhNubah }(h ]h ]h"]h$]h&]uh1j` hj hhhhhKubj )}(hX Depending on its configuration and the capabilities of the platform it runs on,
the Linux kernel can support up to four system sleep states, including
hibernation and up to three variants of system suspend. The sleep states that
can be supported by the kernel are listed below.h]hX Depending on its configuration and the capabilities of the platform it runs on,
the Linux kernel can support up to four system sleep states, including
hibernation and up to three variants of system suspend. The sleep states that
can be supported by the kernel are listed below.}(hj hhhNhNubah }(h ]h ]h"]h$]h&]uh1j hhhKhj hhubhtarget)}(h .. _s2idle:h]h }(h ]h ]h"]h$]h&]refids2idleuh1j( hKphj hhhhubj\ )}(hhh](ja )}(hSuspend-to-Idleh]hSuspend-to-Idle}(hj9 hhhNhNubah }(h ]h ]h"]h$]h&]uh1j` hj6 hhhhhK ubj )}(hX This is a generic, pure software, light-weight variant of system suspend (also
referred to as S2I or S2Idle). It allows more energy to be saved relative to
runtime idle by freezing user space, suspending the timekeeping and putting all
I/O devices into low-power states (possibly lower-power than available in the
working state), such that the processors can spend time in their deepest idle
states while the system is suspended.h]hX This is a generic, pure software, light-weight variant of system suspend (also
referred to as S2I or S2Idle). It allows more energy to be saved relative to
runtime idle by freezing user space, suspending the timekeeping and putting all
I/O devices into low-power states (possibly lower-power than available in the
working state), such that the processors can spend time in their deepest idle
states while the system is suspended.}(hjG hhhNhNubah }(h ]h ]h"]h$]h&]uh1j hhhK hj6 hhubj )}(hThe system is woken up from this state by in-band interrupts, so theoretically
any devices that can cause interrupts to be generated in the working state can
also be set up as wakeup devices for S2Idle.h]hThe system is woken up from this state by in-band interrupts, so theoretically
any devices that can cause interrupts to be generated in the working state can
also be set up as wakeup devices for S2Idle.}(hjU hhhNhNubah }(h ]h ]h"]h$]h&]uh1j hhhK&hj6 hhubj )}(hX= This state can be used on platforms without support for :ref:`standby `
or :ref:`suspend-to-RAM `, or it can be used in addition to any of the
deeper system suspend variants to provide reduced resume latency. It is always
supported if the :c:macro:`CONFIG_SUSPEND` kernel configuration option is set.h](h8This state can be used on platforms without support for }(hjc hhhNhNubh)}(h:ref:`standby `h]hinline)}(hjm h]hstandby}(hjq hhhNhNubah }(h ]h ](xrefstdstd-refeh"]h$]h&]uh1jo hjk ubah }(h ]h ]h"]h$]h&]refdocadmin-guide/pm/sleep-states refdomainj| reftyperef refexplicitrefwarn reftargetstandbyuh1hhhhK*hjc ubh
or }(hjc hhhNhNubh)}(h :ref:`suspend-to-RAM `h]jp )}(hj h]hsuspend-to-RAM}(hj hhhNhNubah }(h ]h ](j{ stdstd-refeh"]h$]h&]uh1jo hj ubah }(h ]h ]h"]h$]h&]refdocj refdomainj reftyperef refexplicitrefwarnj s2ramuh1hhhhK*hjc ubh, or it can be used in addition to any of the
deeper system suspend variants to provide reduced resume latency. It is always
supported if the }(hjc hhhNhNubh)}(h:c:macro:`CONFIG_SUSPEND`h]hliteral)}(hj h]hCONFIG_SUSPEND}(hj hhhNhNubah }(h ]h ](j{ cc-macroeh"]h$]h&]uh1j hj ubah }(h ]h ]h"]h$]h&]refdocj refdomainj reftypemacro refexplicitrefwarnj CONFIG_SUSPENDuh1hhhhK*hjc ubh$ kernel configuration option is set.}(hjc hhhNhNubeh }(h ]h ]h"]h$]h&]uh1j hhhK*hj6 hhubj) )}(h .. _standby:h]h }(h ]h ]h"]h$]h&]j4 standbyuh1j( hKhj6 hhhhubeh }(h ](suspend-to-idlej5 eh ]h"](suspend-to-idles2idleeh$]h&]uh1j[ hj hhhhhK expect_referenced_by_name}j j* sexpect_referenced_by_id}j5 j* subj\ )}(hhh](ja )}(hStandbyh]hStandby}(hj hhhNhNubah }(h ]h ]h"]h$]h&]uh1j` hj hhhhhK2ubj )}(hX This state, if supported, offers moderate, but real, energy savings, while
providing a relatively straightforward transition back to the working state. No
operating state is lost (the system core logic retains power), so the system can
go back to where it left off easily enough.h]hX This state, if supported, offers moderate, but real, energy savings, while
providing a relatively straightforward transition back to the working state. No
operating state is lost (the system core logic retains power), so the system can
go back to where it left off easily enough.}(hj
hhhNhNubah }(h ]h ]h"]h$]h&]uh1j hhhK4hj hhubj )}(hX In addition to freezing user space, suspending the timekeeping and putting all
I/O devices into low-power states, which is done for :ref:`suspend-to-idle
` too, nonboot CPUs are taken offline and all low-level system functions
are suspended during transitions into this state. For this reason, it should
allow more energy to be saved relative to :ref:`suspend-to-idle `, but
the resume latency will generally be greater than for that state.h](hIn addition to freezing user space, suspending the timekeeping and putting all
I/O devices into low-power states, which is done for }(hj hhhNhNubh)}(h :ref:`suspend-to-idle
`h]jp )}(hj% h]hsuspend-to-idle}(hj' hhhNhNubah }(h ]h ](j{ stdstd-refeh"]h$]h&]uh1jo hj# ubah }(h ]h ]h"]h$]h&]refdocj refdomainj1 reftyperef refexplicitrefwarnj s2idleuh1hhhhK9hj ubh too, nonboot CPUs are taken offline and all low-level system functions
are suspended during transitions into this state. For this reason, it should
allow more energy to be saved relative to }(hj hhhNhNubh)}(h :ref:`suspend-to-idle `h]jp )}(hjI h]hsuspend-to-idle}(hjK hhhNhNubah }(h ]h ](j{ stdstd-refeh"]h$]h&]uh1jo hjG ubah }(h ]h ]h"]h$]h&]refdocj refdomainjU reftyperef refexplicitrefwarnj s2idleuh1hhhhK9hj ubhG, but
the resume latency will generally be greater than for that state.}(hj hhhNhNubeh }(h ]h ]h"]h$]h&]uh1j hhhK9hj hhubj )}(hThe set of devices that can wake up the system from this state usually is
reduced relative to :ref:`suspend-to-idle ` and it may be necessary to
rely on the platform for setting up the wakeup functionality as appropriate.h](h^The set of devices that can wake up the system from this state usually is
reduced relative to }(hjq hhhNhNubh)}(h :ref:`suspend-to-idle `h]jp )}(hj{ h]hsuspend-to-idle}(hj} hhhNhNubah }(h ]h ](j{ stdstd-refeh"]h$]h&]uh1jo hjy ubah }(h ]h ]h"]h$]h&]refdocj refdomainj reftyperef refexplicitrefwarnj s2idleuh1hhhhK@hjq ubhh and it may be necessary to
rely on the platform for setting up the wakeup functionality as appropriate.}(hjq hhhNhNubeh }(h ]h ]h"]h$]h&]uh1j hhhK@hj hhubj )}(hX This state is supported if the :c:macro:`CONFIG_SUSPEND` kernel configuration
option is set and the support for it is registered by the platform with the
core system suspend subsystem. On ACPI-based systems this state is mapped to
the S1 system state defined by ACPI.h](h This state is supported if the }(hj hhhNhNubh)}(h:c:macro:`CONFIG_SUSPEND`h]j )}(hj h]hCONFIG_SUSPEND}(hj hhhNhNubah }(h ]h ](j{ j c-macroeh"]h$]h&]uh1j hj ubah }(h ]h ]h"]h$]h&]refdocj refdomainj reftypemacro refexplicitrefwarnj CONFIG_SUSPENDuh1hhhhKDhj ubh kernel configuration
option is set and the support for it is registered by the platform with the
core system suspend subsystem. On ACPI-based systems this state is mapped to
the S1 system state defined by ACPI.}(hj hhhNhNubeh }(h ]h ]h"]h$]h&]uh1j hhhKDhj hhubj) )}(h
.. _s2ram:h]h }(h ]h ]h"]h$]h&]j4 s2ramuh1j( hKhj hhhhubeh }(h ](j id1eh ]h"]standbyah$]standbyah&]uh1j[ hj hhhhhK2
referencedKj }j j sj }j j subj\ )}(hhh](ja )}(hSuspend-to-RAMh]hSuspend-to-RAM}(hj hhhNhNubah }(h ]h ]h"]h$]h&]uh1j` hj hhhhhKLubj )}(hX This state (also referred to as STR or S2RAM), if supported, offers significant
energy savings as everything in the system is put into a low-power state, except
for memory, which should be placed into the self-refresh mode to retain its
contents. All of the steps carried out when entering :ref:`standby `
are also carried out during transitions to S2RAM. Additional operations may
take place depending on the platform capabilities. In particular, on ACPI-based
systems the kernel passes control to the platform firmware (BIOS) as the last
step during S2RAM transitions and that usually results in powering down some
more low-level components that are not directly controlled by the kernel.h](hX# This state (also referred to as STR or S2RAM), if supported, offers significant
energy savings as everything in the system is put into a low-power state, except
for memory, which should be placed into the self-refresh mode to retain its
contents. All of the steps carried out when entering }(hj hhhNhNubh)}(h:ref:`standby `h]jp )}(hj h]hstandby}(hj hhhNhNubah }(h ]h ](j{ stdstd-refeh"]h$]h&]uh1jo hj ubah }(h ]h ]h"]h$]h&]refdocj refdomainj reftyperef refexplicitrefwarnj standbyuh1hhhhKNhj ubhX
are also carried out during transitions to S2RAM. Additional operations may
take place depending on the platform capabilities. In particular, on ACPI-based
systems the kernel passes control to the platform firmware (BIOS) as the last
step during S2RAM transitions and that usually results in powering down some
more low-level components that are not directly controlled by the kernel.}(hj hhhNhNubeh }(h ]h ]h"]h$]h&]uh1j hhhKNhj hhubj )}(hX The state of devices and CPUs is saved and held in memory. All devices are
suspended and put into low-power states. In many cases, all peripheral buses
lose power when entering S2RAM, so devices must be able to handle the transition
back to the "on" state.h]hX The state of devices and CPUs is saved and held in memory. All devices are
suspended and put into low-power states. In many cases, all peripheral buses
lose power when entering S2RAM, so devices must be able to handle the transition
back to the “on” state.}(hj. hhhNhNubah }(h ]h ]h"]h$]h&]uh1j hhhKXhj hhubj )}(hOn ACPI-based systems S2RAM requires some minimal boot-strapping code in the
platform firmware to resume the system from it. This may be the case on other
platforms too.h]hOn ACPI-based systems S2RAM requires some minimal boot-strapping code in the
platform firmware to resume the system from it. This may be the case on other
platforms too.}(hj< hhhNhNubah }(h ]h ]h"]h$]h&]uh1j hhhK]hj hhubj )}(hThe set of devices that can wake up the system from S2RAM usually is reduced
relative to :ref:`suspend-to-idle ` and :ref:`standby ` and it
may be necessary to rely on the platform for setting up the wakeup functionality
as appropriate.h](hYThe set of devices that can wake up the system from S2RAM usually is reduced
relative to }(hjJ hhhNhNubh)}(h :ref:`suspend-to-idle `h]jp )}(hjT h]hsuspend-to-idle}(hjV hhhNhNubah }(h ]h ](j{ stdstd-refeh"]h$]h&]uh1jo hjR ubah }(h ]h ]h"]h$]h&]refdocj refdomainj` reftyperef refexplicitrefwarnj s2idleuh1hhhhKahjJ ubh and }(hjJ hhhNhNubh)}(h:ref:`standby `h]jp )}(hjx h]hstandby}(hjz hhhNhNubah }(h ]h ](j{ stdstd-refeh"]h$]h&]uh1jo hjv ubah }(h ]h ]h"]h$]h&]refdocj refdomainj reftyperef refexplicitrefwarnj standbyuh1hhhhKahjJ ubhh and it
may be necessary to rely on the platform for setting up the wakeup functionality
as appropriate.}(hjJ hhhNhNubeh }(h ]h ]h"]h$]h&]uh1j hhhKahj hhubj )}(hS2RAM is supported if the :c:macro:`CONFIG_SUSPEND` kernel configuration option
is set and the support for it is registered by the platform with the core system
suspend subsystem. On ACPI-based systems it is mapped to the S3 system state
defined by ACPI.h](hS2RAM is supported if the }(hj hhhNhNubh)}(h:c:macro:`CONFIG_SUSPEND`h]j )}(hj h]hCONFIG_SUSPEND}(hj hhhNhNubah }(h ]h ](j{ j c-macroeh"]h$]h&]uh1j hj ubah }(h ]h ]h"]h$]h&]refdocj refdomainj reftypemacro refexplicitrefwarnj CONFIG_SUSPENDuh1hhhhKfhj ubh kernel configuration option
is set and the support for it is registered by the platform with the core system
suspend subsystem. On ACPI-based systems it is mapped to the S3 system state
defined by ACPI.}(hj hhhNhNubeh }(h ]h ]h"]h$]h&]uh1j hhhKfhj hhubj) )}(h.. _hibernation:h]h }(h ]h ]h"]h$]h&]j4 hibernationuh1j( hKhj hhhhubeh }(h ](suspend-to-ramj eh ]h"](suspend-to-rams2rameh$]h&]uh1j[ hj hhhhhKLj }j j sj }j j subj\ )}(hhh](ja )}(h Hibernationh]h Hibernation}(hj hhhNhNubah }(h ]h ]h"]h$]h&]uh1j` hj hhhhhKnubj )}(hX% This state (also referred to as Suspend-to-Disk or STD) offers the greatest
energy savings and can be used even in the absence of low-level platform support
for system suspend. However, it requires some low-level code for resuming the
system to be present for the underlying CPU architecture.h]hX% This state (also referred to as Suspend-to-Disk or STD) offers the greatest
energy savings and can be used even in the absence of low-level platform support
for system suspend. However, it requires some low-level code for resuming the
system to be present for the underlying CPU architecture.}(hj hhhNhNubah }(h ]h ]h"]h$]h&]uh1j hhhKphj hhubj )}(hHibernation is significantly different from any of the system suspend variants.
It takes three system state changes to put it into hibernation and two system
state changes to resume it.h]hHibernation is significantly different from any of the system suspend variants.
It takes three system state changes to put it into hibernation and two system
state changes to resume it.}(hj hhhNhNubah }(h ]h ]h"]h$]h&]uh1j hhhKuhj hhubj )}(hX First, when hibernation is triggered, the kernel stops all system activity and
creates a snapshot image of memory to be written into persistent storage. Next,
the system goes into a state in which the snapshot image can be saved, the image
is written out and finally the system goes into the target low-power state in
which power is cut from almost all of its hardware components, including memory,
except for a limited set of wakeup devices.h]hX First, when hibernation is triggered, the kernel stops all system activity and
creates a snapshot image of memory to be written into persistent storage. Next,
the system goes into a state in which the snapshot image can be saved, the image
is written out and finally the system goes into the target low-power state in
which power is cut from almost all of its hardware components, including memory,
except for a limited set of wakeup devices.}(hj hhhNhNubah }(h ]h ]h"]h$]h&]uh1j hhhKyhj hhubj )}(hX Once the snapshot image has been written out, the system may either enter a
special low-power state (like ACPI S4), or it may simply power down itself.
Powering down means minimum power draw and it allows this mechanism to work on
any system. However, entering a special low-power state may allow additional
means of system wakeup to be used (e.g. pressing a key on the keyboard or
opening a laptop lid).h]hX Once the snapshot image has been written out, the system may either enter a
special low-power state (like ACPI S4), or it may simply power down itself.
Powering down means minimum power draw and it allows this mechanism to work on
any system. However, entering a special low-power state may allow additional
means of system wakeup to be used (e.g. pressing a key on the keyboard or
opening a laptop lid).}(hj" hhhNhNubah }(h ]h ]h"]h$]h&]uh1j hhhKhj hhubj )}(hXb After wakeup, control goes to the platform firmware that runs a boot loader
which boots a fresh instance of the kernel (control may also go directly to
the boot loader, depending on the system configuration, but anyway it causes
a fresh instance of the kernel to be booted). That new instance of the kernel
(referred to as the ``restore kernel``) looks for a hibernation image in
persistent storage and if one is found, it is loaded into memory. Next, all
activity in the system is stopped and the restore kernel overwrites itself with
the image contents and jumps into a special trampoline area in the original
kernel stored in the image (referred to as the ``image kernel``), which is where
the special architecture-specific low-level code is needed. Finally, the
image kernel restores the system to the pre-hibernation state and allows user
space to run again.h](hXH After wakeup, control goes to the platform firmware that runs a boot loader
which boots a fresh instance of the kernel (control may also go directly to
the boot loader, depending on the system configuration, but anyway it causes
a fresh instance of the kernel to be booted). That new instance of the kernel
(referred to as the }(hj0 hhhNhNubj )}(h``restore kernel``h]hrestore kernel}(hj8 hhhNhNubah }(h ]h ]h"]h$]h&]uh1j hj0 ubhX; ) looks for a hibernation image in
persistent storage and if one is found, it is loaded into memory. Next, all
activity in the system is stopped and the restore kernel overwrites itself with
the image contents and jumps into a special trampoline area in the original
kernel stored in the image (referred to as the }(hj0 hhhNhNubj )}(h``image kernel``h]h image kernel}(hjJ hhhNhNubah }(h ]h ]h"]h$]h&]uh1j hj0 ubh), which is where
the special architecture-specific low-level code is needed. Finally, the
image kernel restores the system to the pre-hibernation state and allows user
space to run again.}(hj0 hhhNhNubeh }(h ]h ]h"]h$]h&]uh1j hhhKhj hhubj )}(hHibernation is supported if the :c:macro:`CONFIG_HIBERNATION` kernel
configuration option is set. However, this option can only be set if support
for the given CPU architecture includes the low-level code for system resume.h](h Hibernation is supported if the }(hjb hhhNhNubh)}(h :c:macro:`CONFIG_HIBERNATION`h]j )}(hjl h]hCONFIG_HIBERNATION}(hjn hhhNhNubah }(h ]h ](j{ j c-macroeh"]h$]h&]uh1j hjj ubah }(h ]h ]h"]h$]h&]refdocj refdomainj reftypemacro refexplicitrefwarnj CONFIG_HIBERNATIONuh1hhhhKhjb ubh kernel
configuration option is set. However, this option can only be set if support
for the given CPU architecture includes the low-level code for system resume.}(hjb hhhNhNubeh }(h ]h ]h"]h$]h&]uh1j hhhKhj hhubeh }(h ](j id2eh ]h"] hibernationah$] hibernationah&]uh1j[ hj hhhhhKnj Kj }j j sj }j j subeh }(h ]"sleep-states-that-can-be-supportedah ]h"]"sleep states that can be supportedah$]h&]uh1j[ hj] hhhhhKubj\ )}(hhh](ja )}(h=Basic ``sysfs`` Interfaces for System Suspend and Hibernationh](hBasic }(hj hhhNhNubj )}(h ``sysfs``h]hsysfs}(hj hhhNhNubah }(h ]h ]h"]h$]h&]uh1j hj ubh. Interfaces for System Suspend and Hibernation}(hj hhhNhNubeh }(h ]h ]h"]h$]h&]uh1j` hj hhhhhKubj )}(hXM The power management subsystem provides userspace with a unified ``sysfs``
interface for system sleep regardless of the underlying system architecture or
platform. That interface is located in the :file:`/sys/power/` directory
(assuming that ``sysfs`` is mounted at :file:`/sys`) and it consists of the
following attributes (files):h](hAThe power management subsystem provides userspace with a unified }(hj hhhNhNubj )}(h ``sysfs``h]hsysfs}(hj hhhNhNubah }(h ]h ]h"]h$]h&]uh1j hj ubh|
interface for system sleep regardless of the underlying system architecture or
platform. That interface is located in the }(hj hhhNhNubj )}(h:file:`/sys/power/`h]h /sys/power/}(hj hhhNhNubah }(h ]h ]fileah"]h$]h&]rolefileuh1j hj ubh directory
(assuming that }(hj hhhNhNubj )}(h ``sysfs``h]hsysfs}(hj hhhNhNubah }(h ]h ]h"]h$]h&]uh1j hj ubh is mounted at }(hj hhhNhNubj )}(h :file:`/sys`h]h/sys}(hj
hhhNhNubah }(h ]h ]fileah"]h$]h&]rolefileuh1j hj ubh6) and it consists of the
following attributes (files):}(hj hhhNhNubeh }(h ]h ]h"]h$]h&]uh1j hhhKhj hhubhdefinition_list)}(hhh](hdefinition_list_item)}(hXr ``state``
This file contains a list of strings representing sleep states supported
by the kernel. Writing one of these strings into it causes the kernel
to start a transition of the system into the sleep state represented by
that string.
In particular, the "disk", "freeze" and "standby" strings represent the
:ref:`hibernation `, :ref:`suspend-to-idle ` and
:ref:`standby ` sleep states, respectively. The "mem" string
is interpreted in accordance with the contents of the ``mem_sleep`` file
described below.
If the kernel does not support any system sleep states, this file is
not present.
h](hterm)}(h ``state``h]j )}(hj4
h]hstate}(hj6
hhhNhNubah }(h ]h ]h"]h$]h&]uh1j hj2
ubah }(h ]h ]h"]h$]h&]uh1j0
hhhKhj,
ubh
definition)}(hhh](j )}(hThis file contains a list of strings representing sleep states supported
by the kernel. Writing one of these strings into it causes the kernel
to start a transition of the system into the sleep state represented by
that string.h]hThis file contains a list of strings representing sleep states supported
by the kernel. Writing one of these strings into it causes the kernel
to start a transition of the system into the sleep state represented by
that string.}(hjN
hhhNhNubah }(h ]h ]h"]h$]h&]uh1j hhhKhjK
ubj )}(hX. In particular, the "disk", "freeze" and "standby" strings represent the
:ref:`hibernation `, :ref:`suspend-to-idle ` and
:ref:`standby ` sleep states, respectively. The "mem" string
is interpreted in accordance with the contents of the ``mem_sleep`` file
described below.h](hTIn particular, the “disk”, “freeze” and “standby” strings represent the
}(hj\
hhhNhNubh)}(h :ref:`hibernation `h]jp )}(hjf
h]h hibernation}(hjh
hhhNhNubah }(h ]h ](j{ stdstd-refeh"]h$]h&]uh1jo hjd
ubah }(h ]h ]h"]h$]h&]refdocj refdomainjr
reftyperef refexplicitrefwarnj hibernationuh1hhhhKhj\
ubh, }(hj\
hhhNhNubh)}(h :ref:`suspend-to-idle `h]jp )}(hj
h]hsuspend-to-idle}(hj
hhhNhNubah }(h ]h ](j{ stdstd-refeh"]h$]h&]uh1jo hj
ubah }(h ]h ]h"]h$]h&]refdocj refdomainj
reftyperef refexplicitrefwarnj s2idleuh1hhhhKhj\
ubh and
}(hj\
hhhNhNubh)}(h:ref:`standby `h]jp )}(hj
h]hstandby}(hj
hhhNhNubah }(h ]h ](j{ stdstd-refeh"]h$]h&]uh1jo hj
ubah }(h ]h ]h"]h$]h&]refdocj refdomainj
reftyperef refexplicitrefwarnj standbyuh1hhhhKhj\
ubhi sleep states, respectively. The “mem” string
is interpreted in accordance with the contents of the }(hj\
hhhNhNubj )}(h
``mem_sleep``h]h mem_sleep}(hj
hhhNhNubah }(h ]h ]h"]h$]h&]uh1j hj\
ubh file
described below.}(hj\
hhhNhNubeh }(h ]h ]h"]h$]h&]uh1j hhhKhjK
ubj )}(hQIf the kernel does not support any system sleep states, this file is
not present.h]hQIf the kernel does not support any system sleep states, this file is
not present.}(hj
hhhNhNubah }(h ]h ]h"]h$]h&]uh1j hhhKhjK
ubeh }(h ]h ]h"]h$]h&]uh1jI
hj,
ubeh }(h ]h ]h"]h$]h&]uh1j*
hhhKhj'
ubj+
)}(hXk ``mem_sleep``
This file contains a list of strings representing supported system
suspend variants and allows user space to select the variant to be
associated with the "mem" string in the ``state`` file described above.
The strings that may be present in this file are "s2idle", "shallow"
and "deep". The "s2idle" string always represents :ref:`suspend-to-idle
` and, by convention, "shallow" and "deep" represent
:ref:`standby ` and :ref:`suspend-to-RAM `,
respectively.
Writing one of the listed strings into this file causes the system
suspend variant represented by it to be associated with the "mem" string
in the ``state`` file. The string representing the suspend variant
currently associated with the "mem" string in the ``state`` file is
shown in square brackets.
If the kernel does not support system suspend, this file is not present.
h](j1
)}(h
``mem_sleep``h]j )}(hj h]h mem_sleep}(hj
hhhNhNubah }(h ]h ]h"]h$]h&]uh1j hj ubah }(h ]h ]h"]h$]h&]uh1j0
hhhKhj ubjJ
)}(hhh](j )}(hThis file contains a list of strings representing supported system
suspend variants and allows user space to select the variant to be
associated with the "mem" string in the ``state`` file described above.h](hThis file contains a list of strings representing supported system
suspend variants and allows user space to select the variant to be
associated with the “mem” string in the }(hj hhhNhNubj )}(h ``state``h]hstate}(hj( hhhNhNubah }(h ]h ]h"]h$]h&]uh1j hj ubh file described above.}(hj hhhNhNubeh }(h ]h ]h"]h$]h&]uh1j hhhKhj ubj )}(hX The strings that may be present in this file are "s2idle", "shallow"
and "deep". The "s2idle" string always represents :ref:`suspend-to-idle
` and, by convention, "shallow" and "deep" represent
:ref:`standby ` and :ref:`suspend-to-RAM `,
respectively.h](hThe strings that may be present in this file are “s2idle”, “shallow”
and “deep”. The “s2idle” string always represents }(hj@ hhhNhNubh)}(h :ref:`suspend-to-idle
`h]jp )}(hjJ h]hsuspend-to-idle}(hjL hhhNhNubah }(h ]h ](j{ stdstd-refeh"]h$]h&]uh1jo hjH ubah }(h ]h ]h"]h$]h&]refdocj refdomainjV reftyperef refexplicitrefwarnj s2idleuh1hhhhKhj@ ubh< and, by convention, “shallow” and “deep” represent
}(hj@ hhhNhNubh)}(h:ref:`standby `h]jp )}(hjn h]hstandby}(hjp hhhNhNubah }(h ]h ](j{ stdstd-refeh"]h$]h&]uh1jo hjl ubah }(h ]h ]h"]h$]h&]refdocj refdomainjz reftyperef refexplicitrefwarnj standbyuh1hhhhKhj@ ubh and }(hj@ hhhNhNubh)}(h :ref:`suspend-to-RAM `h]jp )}(hj h]hsuspend-to-RAM}(hj hhhNhNubah }(h ]h ](j{ stdstd-refeh"]h$]h&]uh1jo hj ubah }(h ]h ]h"]h$]h&]refdocj refdomainj reftyperef refexplicitrefwarnj s2ramuh1hhhhKhj@ ubh,
respectively.}(hj@ hhhNhNubeh }(h ]h ]h"]h$]h&]uh1j hhhKhj ubj )}(hX- Writing one of the listed strings into this file causes the system
suspend variant represented by it to be associated with the "mem" string
in the ``state`` file. The string representing the suspend variant
currently associated with the "mem" string in the ``state`` file is
shown in square brackets.h](hWriting one of the listed strings into this file causes the system
suspend variant represented by it to be associated with the “mem” string
in the }(hj hhhNhNubj )}(h ``state``h]hstate}(hj hhhNhNubah }(h ]h ]h"]h$]h&]uh1j hj ubhj file. The string representing the suspend variant
currently associated with the “mem” string in the }(hj hhhNhNubj )}(h ``state``h]hstate}(hj hhhNhNubah }(h ]h ]h"]h$]h&]uh1j hj ubh" file is
shown in square brackets.}(hj hhhNhNubeh }(h ]h ]h"]h$]h&]uh1j hhhKhj ubj )}(hHIf the kernel does not support system suspend, this file is not present.h]hHIf the kernel does not support system suspend, this file is not present.}(hj hhhNhNubah }(h ]h ]h"]h$]h&]uh1j hhhKhj ubeh }(h ]h ]h"]h$]h&]uh1jI
hj ubeh }(h ]h ]h"]h$]h&]uh1j*
hhhKhj'
hhubj+
)}(hXV ``disk``
This file controls the operating mode of hibernation (Suspend-to-Disk).
Specifically, it tells the kernel what to do after creating a
hibernation image.
Reading from it returns a list of supported options encoded as:
``platform``
Put the system into a special low-power state (e.g. ACPI S4) to
make additional wakeup options available and possibly allow the
platform firmware to take a simplified initialization path after
wakeup.
It is only available if the platform provides a special
mechanism to put the system to sleep after creating a
hibernation image (platforms with ACPI do that as a rule, for
example).
``shutdown``
Power off the system.
``reboot``
Reboot the system (useful for diagnostics mostly).
``suspend``
Hybrid system suspend. Put the system into the suspend sleep
state selected through the ``mem_sleep`` file described above.
If the system is successfully woken up from that state, discard
the hibernation image and continue. Otherwise, use the image
to restore the previous state of the system.
It is available if system suspend is supported.
``test_resume``
Diagnostic operation. Load the image as though the system had
just woken up from hibernation and the currently running kernel
instance was a restore kernel and follow up with full system
resume.
Writing one of the strings listed above into this file causes the option
represented by it to be selected.
The currently selected option is shown in square brackets, which means
that the operation represented by it will be carried out after creating
and saving the image when hibernation is triggered by writing ``disk``
to :file:`/sys/power/state`.
If the kernel does not support hibernation, this file is not present.
h](j1
)}(h``disk``h]j )}(hj h]hdisk}(hj hhhNhNubah }(h ]h ]h"]h$]h&]uh1j hj
ubah }(h ]h ]h"]h$]h&]uh1j0
hhhKhj ubjJ
)}(hhh](j )}(hThis file controls the operating mode of hibernation (Suspend-to-Disk).
Specifically, it tells the kernel what to do after creating a
hibernation image.h]hThis file controls the operating mode of hibernation (Suspend-to-Disk).
Specifically, it tells the kernel what to do after creating a
hibernation image.}(hj$ hhhNhNubah }(h ]h ]h"]h$]h&]uh1j hhhKhj! ubj )}(h?Reading from it returns a list of supported options encoded as:h]h?Reading from it returns a list of supported options encoded as:}(hj2 hhhNhNubah }(h ]h ]h"]h$]h&]uh1j hhhKhj! ubj&
)}(hhh](j+
)}(hX ``platform``
Put the system into a special low-power state (e.g. ACPI S4) to
make additional wakeup options available and possibly allow the
platform firmware to take a simplified initialization path after
wakeup.
It is only available if the platform provides a special
mechanism to put the system to sleep after creating a
hibernation image (platforms with ACPI do that as a rule, for
example).
h](j1
)}(h ``platform``h]j )}(hjI h]hplatform}(hjK hhhNhNubah }(h ]h ]h"]h$]h&]uh1j hjG ubah }(h ]h ]h"]h$]h&]uh1j0
hhhKhjC ubjJ
)}(hhh](j )}(hPut the system into a special low-power state (e.g. ACPI S4) to
make additional wakeup options available and possibly allow the
platform firmware to take a simplified initialization path after
wakeup.h]hPut the system into a special low-power state (e.g. ACPI S4) to
make additional wakeup options available and possibly allow the
platform firmware to take a simplified initialization path after
wakeup.}(hja hhhNhNubah }(h ]h ]h"]h$]h&]uh1j hhhKhj^ ubj )}(hIt is only available if the platform provides a special
mechanism to put the system to sleep after creating a
hibernation image (platforms with ACPI do that as a rule, for
example).h]hIt is only available if the platform provides a special
mechanism to put the system to sleep after creating a
hibernation image (platforms with ACPI do that as a rule, for
example).}(hjo hhhNhNubah }(h ]h ]h"]h$]h&]uh1j hhhKhj^ ubeh }(h ]h ]h"]h$]h&]uh1jI
hjC ubeh }(h ]h ]h"]h$]h&]uh1j*
hhhKhj@ ubj+
)}(h#``shutdown``
Power off the system.
h](j1
)}(h ``shutdown``h]j )}(hj h]hshutdown}(hj hhhNhNubah }(h ]h ]h"]h$]h&]uh1j hj ubah }(h ]h ]h"]h$]h&]uh1j0
hhhKhj ubjJ
)}(hhh]j )}(hPower off the system.h]hPower off the system.}(hj hhhNhNubah }(h ]h ]h"]h$]h&]uh1j hhhKhj ubah }(h ]h ]h"]h$]h&]uh1jI
hj ubeh }(h ]h ]h"]h$]h&]uh1j*
hhhKhj@ ubj+
)}(h>``reboot``
Reboot the system (useful for diagnostics mostly).
h](j1
)}(h
``reboot``h]j )}(hj h]hreboot}(hj hhhNhNubah }(h ]h ]h"]h$]h&]uh1j hj ubah }(h ]h ]h"]h$]h&]uh1j0
hhhKhj ubjJ
)}(hhh]j )}(h2Reboot the system (useful for diagnostics mostly).h]h2Reboot the system (useful for diagnostics mostly).}(hj hhhNhNubah }(h ]h ]h"]h$]h&]uh1j hhhKhj ubah }(h ]h ]h"]h$]h&]uh1jI
hj ubeh }(h ]h ]h"]h$]h&]uh1j*
hhhKhj@ ubj+
)}(hXe ``suspend``
Hybrid system suspend. Put the system into the suspend sleep
state selected through the ``mem_sleep`` file described above.
If the system is successfully woken up from that state, discard
the hibernation image and continue. Otherwise, use the image
to restore the previous state of the system.
It is available if system suspend is supported.
h](j1
)}(h ``suspend``h]j )}(hj h]hsuspend}(hj
hhhNhNubah }(h ]h ]h"]h$]h&]uh1j hj ubah }(h ]h ]h"]h$]h&]uh1j0
hhhKhj ubjJ
)}(hhh](j )}(hX' Hybrid system suspend. Put the system into the suspend sleep
state selected through the ``mem_sleep`` file described above.
If the system is successfully woken up from that state, discard
the hibernation image and continue. Otherwise, use the image
to restore the previous state of the system.h](hYHybrid system suspend. Put the system into the suspend sleep
state selected through the }(hj
hhhNhNubj )}(h
``mem_sleep``h]h mem_sleep}(hj
hhhNhNubah }(h ]h ]h"]h$]h&]uh1j hj
ubh file described above.
If the system is successfully woken up from that state, discard
the hibernation image and continue. Otherwise, use the image
to restore the previous state of the system.}(hj
hhhNhNubeh }(h ]h ]h"]h$]h&]uh1j hhhKhj
ubj )}(h/It is available if system suspend is supported.h]h/It is available if system suspend is supported.}(hj7
hhhNhNubah }(h ]h ]h"]h$]h&]uh1j hhhKhj
ubeh }(h ]h ]h"]h$]h&]uh1jI
hj ubeh }(h ]h ]h"]h$]h&]uh1j*
hhhKhj@ ubj+
)}(h``test_resume``
Diagnostic operation. Load the image as though the system had
just woken up from hibernation and the currently running kernel
instance was a restore kernel and follow up with full system
resume.
h](j1
)}(h``test_resume``h]j )}(hjW
h]h test_resume}(hjY
hhhNhNubah }(h ]h ]h"]h$]h&]uh1j hjU
ubah }(h ]h ]h"]h$]h&]uh1j0
hhhKhjQ
ubjJ
)}(hhh]j )}(hDiagnostic operation. Load the image as though the system had
just woken up from hibernation and the currently running kernel
instance was a restore kernel and follow up with full system
resume.h]hDiagnostic operation. Load the image as though the system had
just woken up from hibernation and the currently running kernel
instance was a restore kernel and follow up with full system
resume.}(hjo
hhhNhNubah }(h ]h ]h"]h$]h&]uh1j hhhKhjl
ubah }(h ]h ]h"]h$]h&]uh1jI
hjQ
ubeh }(h ]h ]h"]h$]h&]uh1j*
hhhKhj@ ubeh }(h ]h ]h"]h$]h&]uh1j%
hj! ubj )}(hjWriting one of the strings listed above into this file causes the option
represented by it to be selected.h]hjWriting one of the strings listed above into this file causes the option
represented by it to be selected.}(hj
hhhNhNubah }(h ]h ]h"]h$]h&]uh1j hhhKhj! ubj )}(hThe currently selected option is shown in square brackets, which means
that the operation represented by it will be carried out after creating
and saving the image when hibernation is triggered by writing ``disk``
to :file:`/sys/power/state`.h](hThe currently selected option is shown in square brackets, which means
that the operation represented by it will be carried out after creating
and saving the image when hibernation is triggered by writing }(hj
hhhNhNubj )}(h``disk``h]hdisk}(hj
hhhNhNubah }(h ]h ]h"]h$]h&]uh1j hj
ubh
to }(hj
hhhNhNubj )}(h:file:`/sys/power/state`h]h/sys/power/state}(hj
hhhNhNubah }(h ]h ]fileah"]h$]h&]rolefileuh1j hj
ubh.}(hj
hhhNhNubeh }(h ]h ]h"]h$]h&]uh1j hhhKhj! ubj )}(hEIf the kernel does not support hibernation, this file is not present.h]hEIf the kernel does not support hibernation, this file is not present.}(hj
hhhNhNubah }(h ]h ]h"]h$]h&]uh1j hhhKhj! ubeh }(h ]h ]h"]h$]h&]uh1jI
hj ubeh }(h ]h ]h"]h$]h&]uh1j*
hhhKhj'
hhubj+
)}(hX ``image_size``
This file controls the size of hibernation images.
It can be written a string representing a non-negative integer that will
be used as a best-effort upper limit of the image size, in bytes. The
hibernation core will do its best to ensure that the image size will not
exceed that number, but if that turns out to be impossible to achieve, a
hibernation image will still be created and its size will be as small as
possible. In particular, writing '0' to this file causes the size of
hibernation images to be minimum.
Reading from it returns the current image size limit, which is set to
around 2/5 of the available RAM size by default.
h](j1
)}(h``image_size``h]j )}(hj
h]h
image_size}(hj
hhhNhNubah }(h ]h ]h"]h$]h&]uh1j hj
ubah }(h ]h ]h"]h$]h&]uh1j0
hhhMhj
ubjJ
)}(hhh](j )}(h2This file controls the size of hibernation images.h]h2This file controls the size of hibernation images.}(hj
hhhNhNubah }(h ]h ]h"]h$]h&]uh1j hhhKhj ubj )}(hX It can be written a string representing a non-negative integer that will
be used as a best-effort upper limit of the image size, in bytes. The
hibernation core will do its best to ensure that the image size will not
exceed that number, but if that turns out to be impossible to achieve, a
hibernation image will still be created and its size will be as small as
possible. In particular, writing '0' to this file causes the size of
hibernation images to be minimum.h]hX It can be written a string representing a non-negative integer that will
be used as a best-effort upper limit of the image size, in bytes. The
hibernation core will do its best to ensure that the image size will not
exceed that number, but if that turns out to be impossible to achieve, a
hibernation image will still be created and its size will be as small as
possible. In particular, writing ‘0’ to this file causes the size of
hibernation images to be minimum.}(hj hhhNhNubah }(h ]h ]h"]h$]h&]uh1j hhhKhj ubj )}(hvReading from it returns the current image size limit, which is set to
around 2/5 of the available RAM size by default.h]hvReading from it returns the current image size limit, which is set to
around 2/5 of the available RAM size by default.}(hj& hhhNhNubah }(h ]h ]h"]h$]h&]uh1j hhhM hj ubeh }(h ]h ]h"]h$]h&]uh1jI
hj
ubeh }(h ]h ]h"]h$]h&]uh1j*
hhhMhj'
hhubj+
)}(hX ``pm_trace``
This file controls the "PM trace" mechanism saving the last suspend
or resume event point in the RTC memory across reboots. It helps to
debug hard lockups or reboots due to device driver failures that occur
during system suspend or resume (which is more common) more effectively.
If it contains "1", the fingerprint of each suspend/resume event point
in turn will be stored in the RTC memory (overwriting the actual RTC
information), so it will survive a system crash if one occurs right
after storing it and it can be used later to identify the driver that
caused the crash to happen.
It contains "0" by default, which may be changed to "1" by writing a
string representing a nonzero integer into it.
h](j1
)}(h ``pm_trace``h]j )}(hjF h]hpm_trace}(hjH hhhNhNubah }(h ]h ]h"]h$]h&]uh1j hjD ubah }(h ]h ]h"]h$]h&]uh1j0
hhhMhj@ ubjJ
)}(hhh](j )}(hX This file controls the "PM trace" mechanism saving the last suspend
or resume event point in the RTC memory across reboots. It helps to
debug hard lockups or reboots due to device driver failures that occur
during system suspend or resume (which is more common) more effectively.h]hX This file controls the “PM trace” mechanism saving the last suspend
or resume event point in the RTC memory across reboots. It helps to
debug hard lockups or reboots due to device driver failures that occur
during system suspend or resume (which is more common) more effectively.}(hj^ hhhNhNubah }(h ]h ]h"]h$]h&]uh1j hhhMhj[ ubj )}(hX1 If it contains "1", the fingerprint of each suspend/resume event point
in turn will be stored in the RTC memory (overwriting the actual RTC
information), so it will survive a system crash if one occurs right
after storing it and it can be used later to identify the driver that
caused the crash to happen.h]hX5 If it contains “1”, the fingerprint of each suspend/resume event point
in turn will be stored in the RTC memory (overwriting the actual RTC
information), so it will survive a system crash if one occurs right
after storing it and it can be used later to identify the driver that
caused the crash to happen.}(hjl hhhNhNubah }(h ]h ]h"]h$]h&]uh1j hhhM hj[ ubj )}(hsIt contains "0" by default, which may be changed to "1" by writing a
string representing a nonzero integer into it.h]h{It contains “0” by default, which may be changed to “1” by writing a
string representing a nonzero integer into it.}(hjz hhhNhNubah }(h ]h ]h"]h$]h&]uh1j hhhMhj[ ubeh }(h ]h ]h"]h$]h&]uh1jI
hj@ ubeh }(h ]h ]h"]h$]h&]uh1j*
hhhMhj'
hhubeh }(h ]h ]h"]h$]h&]uh1j%
hj hhhhhNubj )}(hX According to the above, there are two ways to make the system go into the
:ref:`suspend-to-idle ` state. The first one is to write "freeze"
directly to :file:`/sys/power/state`. The second one is to write "s2idle" to
:file:`/sys/power/mem_sleep` and then to write "mem" to
:file:`/sys/power/state`. Likewise, there are two ways to make the system go
into the :ref:`standby ` state (the strings to write to the control
files in that case are "standby" or "shallow" and "mem", respectively) if that
state is supported by the platform. However, there is only one way to make the
system go into the :ref:`suspend-to-RAM ` state (write "deep" into
:file:`/sys/power/mem_sleep` and "mem" into :file:`/sys/power/state`).h](hJAccording to the above, there are two ways to make the system go into the
}(hj hhhNhNubh)}(h :ref:`suspend-to-idle `h]jp )}(hj h]hsuspend-to-idle}(hj hhhNhNubah }(h ]h ](j{ stdstd-refeh"]h$]h&]uh1jo hj ubah }(h ]h ]h"]h$]h&]refdocj refdomainj reftyperef refexplicitrefwarnj s2idleuh1hhhhMhj ubh< state. The first one is to write “freeze”
directly to }(hj hhhNhNubj )}(h:file:`/sys/power/state`h]h/sys/power/state}(hj hhhNhNubah }(h ]h ]fileah"]h$]h&]rolefileuh1j hj ubh.. The second one is to write “s2idle” to
}(hj hhhNhNubj )}(h :file:`/sys/power/mem_sleep`h]h/sys/power/mem_sleep}(hj hhhNhNubah }(h ]h ]fileah"]h$]h&]rolefileuh1j hj ubh and then to write “mem” to
}(hj hhhNhNubj )}(h:file:`/sys/power/state`h]h/sys/power/state}(hj hhhNhNubah }(h ]h ]fileah"]h$]h&]rolefileuh1j hj ubh?. Likewise, there are two ways to make the system go
into the }(hj hhhNhNubh)}(h:ref:`standby `h]jp )}(hj h]hstandby}(hj hhhNhNubah }(h ]h ](j{ stdstd-refeh"]h$]h&]uh1jo hj ubah }(h ]h ]h"]h$]h&]refdocj refdomainj reftyperef refexplicitrefwarnj standbyuh1hhhhMhj ubh state (the strings to write to the control
files in that case are “standby” or “shallow” and “mem”, respectively) if that
state is supported by the platform. However, there is only one way to make the
system go into the }(hj hhhNhNubh)}(h :ref:`suspend-to-RAM `h]jp )}(hj+ h]hsuspend-to-RAM}(hj- hhhNhNubah }(h ]h ](j{ stdstd-refeh"]h$]h&]uh1jo hj) ubah }(h ]h ]h"]h$]h&]refdocj refdomainj7 reftyperef refexplicitrefwarnj s2ramuh1hhhhMhj ubh state (write “deep” into
}(hj hhhNhNubj )}(h :file:`/sys/power/mem_sleep`h]h/sys/power/mem_sleep}(hjM hhhNhNubah }(h ]h ]fileah"]h$]h&]rolefileuh1j hj ubh and “mem” into }(hj hhhNhNubj )}(h:file:`/sys/power/state` h]h/sys/power/state}(hjb hhhNhNubah }(h ]h ]fileah"]h$]h&]rolefileuh1j hj ubh).}(hj hhhNhNubeh }(h ]h ]h"]h$]h&]uh1j hhhMhj hhubj )}(hX The default suspend variant (ie. the one to be used without writing anything
into :file:`/sys/power/mem_sleep`) is either "deep" (on the majority of systems
supporting :ref:`suspend-to-RAM `) or "s2idle", but it can be overridden
by the value of the ``mem_sleep_default`` parameter in the kernel command line.
On some systems with ACPI, depending on the information in the ACPI tables, the
default may be "s2idle" even if :ref:`suspend-to-RAM ` is supported in
principle.h](hRThe default suspend variant (ie. the one to be used without writing anything
into }(hj} hhhNhNubj )}(h :file:`/sys/power/mem_sleep`h]h/sys/power/mem_sleep}(hj hhhNhNubah }(h ]h ]fileah"]h$]h&]rolefileuh1j hj} ubh>) is either “deep” (on the majority of systems
supporting }(hj} hhhNhNubh)}(h :ref:`suspend-to-RAM `h]jp )}(hj h]hsuspend-to-RAM}(hj hhhNhNubah }(h ]h ](j{ stdstd-refeh"]h$]h&]uh1jo hj ubah }(h ]h ]h"]h$]h&]refdocj refdomainj reftyperef refexplicitrefwarnj s2ramuh1hhhhM hj} ubh@) or “s2idle”, but it can be overridden
by the value of the }(hj} hhhNhNubj )}(h``mem_sleep_default``h]hmem_sleep_default}(hj hhhNhNubah }(h ]h ]h"]h$]h&]uh1j hj} ubh parameter in the kernel command line.
On some systems with ACPI, depending on the information in the ACPI tables, the
default may be “s2idle” even if }(hj} hhhNhNubh)}(h :ref:`suspend-to-RAM `h]jp )}(hj h]hsuspend-to-RAM}(hj hhhNhNubah }(h ]h ](j{ stdstd-refeh"]h$]h&]uh1jo hj ubah }(h ]h ]h"]h$]h&]refdocj refdomainj reftyperef refexplicitrefwarnj s2ramuh1hhhhM hj} ubh is supported in
principle.}(hj} hhhNhNubeh }(h ]h ]h"]h$]h&]uh1j hhhM hj hhubeh }(h ]9basic-sysfs-interfaces-for-system-suspend-and-hibernationah ]h"]9basic sysfs interfaces for system suspend and hibernationah$]h&]uh1j[ hj] hhhhhKubeh }(h ]system-sleep-statesah ]h"]system sleep statesah$]h&]uh1j[ hhhhhhhKubeh }(h ]h ]h"]h$]h&]sourcehuh1hcurrent_sourceN current_lineNsettingsdocutils.frontendValues)}(j` N generatorN datestampN source_linkN
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id_counter collectionsCounter}j; KsRparse_messages](hsystem_message)}(hhh]j )}(h*Duplicate implicit target name: "standby".h]h.Duplicate implicit target name: “standby”.}(hj hhhNhNubah }(h ]h ]h"]h$]h&]uh1j hj ubah }(h ]h ]h"]h$]h&]j alevelKtypeINFOsourcehnjlineK2uh1j hj hhhhhK2ubj )}(hhh]j )}(h.Duplicate implicit target name: "hibernation".h]h2Duplicate implicit target name: “hibernation”.}(hj hhhNhNubah }(h ]h ]h"]h$]h&]uh1j hj ubah }(h ]h ]h"]h$]h&]j alevelKtypej sourcehnjlineKnuh1j hj hhhhhKnubetransform_messages](j )}(hhh]j )}(hhh]h,Hyperlink target "s2idle" is not referenced.}hj sbah }(h ]h ]h"]h$]h&]uh1j hj ubah }(h ]h ]h"]h$]h&]levelKtypej sourcehnjlineKpuh1j ubj )}(hhh]j )}(hhh]h-Hyperlink target "standby" is not referenced.}hj7 sbah }(h ]h ]h"]h$]h&]uh1j hj4 ubah }(h ]h ]h"]h$]h&]levelKtypej sourcehnjlineKuh1j ubj )}(hhh]j )}(hhh]h+Hyperlink target "s2ram" is not referenced.}hjQ sbah }(h ]h ]h"]h$]h&]uh1j hjN ubah }(h ]h ]h"]h$]h&]levelKtypej sourcehnjlineKuh1j ubj )}(hhh]j )}(hhh]h1Hyperlink target "hibernation" is not referenced.}hjk sbah }(h ]h ]h"]h$]h&]uh1j hjh ubah }(h ]h ]h"]h$]h&]levelKtypej sourcehnjlineKuh1j ube transformerN include_log]-Documentation/admin-guide/pm/sleep-states.rst(NNNNta
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