Lines Matching full:states

28 processor's functional blocks into low-power states.  That instruction takes two
42 .. _intel-idle-enumeration-of-states:
44 Enumeration of Idle States
50 as C-states (in the ACPI terminology) or idle states.  The list of meaningful
51 ``MWAIT`` hint values and idle states (i.e. low-power configurations of the
55 In order to create a list of available idle states required by the ``CPUIdle``
56 subsystem (see :ref:`idle-states-representation` in
58 ``intel_idle`` can use two sources of information: static tables of idle states
69 states, ``intel_idle`` first looks for a ``_CST`` object under one of the ACPI
72 ``CPUIdle`` subsystem expects that the list of idle states supplied by the
76 state description and such that all of the idle states included in its return
81 descriptions extracted from it are stored in a preliminary list of idle states
85 Next, the first (index 0) entry in the list of available idle states is
92 the "internal" table is the primary source of information on idle states and the
93 information from it is copied to the final list of available idle states.  If
94 using the ACPI tables for the enumeration of idle states is not required
98 states may not be enabled by default if there are no matching entries in the
99 preliminary list of idle states coming from the ACPI tables.  In that case user
102 :ref:`idle-states-representation` in
104 the idle states "known" to the driver may not be enabled by default if they have
108 supports ``MWAIT``, the preliminary list of idle states coming from the ACPI
112 entry in the final list of idle states.  The name of the idle state represented
117 C1-type idle states the exit latency value is also used as the target residency
118 (for compatibility with the majority of the "internal" tables of idle states for
123 All of the idle states in the final list are enabled by default in this case.
136 driver, which determines the idle states enumeration method (see
144 `below <intel-idle-parameters_>`_), the idle states information provided by the
148 available idle states is created as explained
178 of idle states supplied to the ``CPUIdle`` core during the registration of the
179 driver.  It is also the maximum number of regular (non-polling) idle states that
180 can be used by ``intel_idle``, so the enumeration of idle states is terminated
181 after finding that number of usable idle states (the other idle states that
184 ``intel_idle`` from exposing idle states that are regarded as "too deep" for
188 states in question cannot be enabled during system startup, because in the
190 QoS) feature can be used to prevent ``CPUIdle`` from touching those idle states
202 list of idle states to be disabled by default in the form of a bitmask.
205 the indices of idle states to be disabled by default (as reflected by the names
208 idle state; see :ref:`idle-states-representation` in
212 states 0 and 1 by default, and if it is equal to 8, idle state 3 will be
216 The idle states disabled this way can be enabled (on a per-CPU basis) from user
230 mode to off when the CPU is in any one of the available idle states.  This may
235 .. _intel-idle-core-and-package-idle-states:
237 Core and Package Levels of Idle States
241 least) two levels of idle states (or C-states).  One level, referred to as
242 "core C-states", covers individual cores in the processor, whereas the other
243 level, referred to as "package C-states", covers the entire processor package
247 Some of the ``MWAIT`` hint values allow the processor to use core C-states only
266 As a rule, there is no simple way to make the processor use core C-states only
267 if the conditions for entering the corresponding package C-states are met, so
272 tables of idle states in ``intel_idle`` reflect the properties of package
273 C-states.]  If using package C-states is not desirable at all, either
276 restrict the range of permissible idle states to the ones with core-level only