2cffe9f6 - cpuidle: add haltpoll governor

Wed, 03 Jul 2019 23:51:28 +0000

cpuidle: add haltpoll governorThe cpuidle_haltpoll governor, in conjunction with the haltpoll cpuidledriver, allows guest vcpus to poll for a specified amount of time beforehalting.This provides the following benefits to host side polling: 1) The POLL flag is set while polling is performed, which allows a remote vCPU to avoid sending an IPI (and the associated cost of handling the IPI) when performing a wakeup. 2) The VM-exit cost can be avoided.The downside of guest side polling is that polling is performedeven with other runnable tasks in the host.Results comparing halt_poll_ns and server/client applicationwhere a small packet is ping-ponged:host --> 31.33halt_poll_ns=300000 / no guest busy spin --> 33.40 (93.8%)halt_poll_ns=0 / guest_halt_poll_ns=300000 --> 32.73 (95.7%)For the SAP HANA benchmarks (where idle_spin is a parameterof the previous version of the patch, results should be thesame):hpns == halt_poll_ns idle_spin=0/ idle_spin=800/ idle_spin=0/ hpns=200000 hpns=0 hpns=800000DeleteC06T03 (100 thread) 1.76 1.71 (-3%) 1.78 (+1%)InsertC16T02 (100 thread) 2.14 2.07 (-3%) 2.18 (+1.8%)DeleteC00T01 (1 thread) 1.34 1.28 (-4.5%) 1.29 (-3.7%)UpdateC00T03 (1 thread) 4.72 4.18 (-12%) 4.53 (-5%)Signed-off-by: Marcelo Tosatti Signed-off-by: Rafael J. Wysocki List of files: /linux-6.15/drivers/cpuidle/governors/Makefile

ec8f24b7 - treewide: Add SPDX license identifier - Makefile/Kconfig

Sun, 19 May 2019 12:07:45 +0000

treewide: Add SPDX license identifier - Makefile/KconfigAdd SPDX license identifiers to all Make/Kconfig files which: - Have no license information of any formThese files fall under the project license, GPL v2 only. The resulting SPDXlicense identifier is: GPL-2.0-onlySigned-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman List of files: /linux-6.15/drivers/cpuidle/governors/Makefile

b26bf6ab - cpuidle: New timer events oriented governor for tickless systems

Fri, 04 Jan 2019 11:30:47 +0000

cpuidle: New timer events oriented governor for tickless systemsThe venerable menu governor does some things that are quitequestionable in my view.First, it includes timer wakeups in the pattern detection data andmixes them up with wakeups from other sources which in some casescauses it to expect what essentially would be a timer wakeup in atime frame in which no timer wakeups are possible (because it knowsthe time until the next timer event and that is later than theexpected wakeup time).Second, it uses the extra exit latency limit based on the predictedidle duration and depending on the number of tasks waiting on I/O,even though those tasks may run on a different CPU when they arewoken up. Moreover, the time ranges used by it for the sleep lengthcorrection factors depend on whether or not there are tasks waitingon I/O, which again doesn't imply anything in particular, and theyare not correlated to the list of available idle states in any waywhatever.Also, the pattern detection code in menu may end up consideringvalues that are too large to matter at all, in which cases runningit is a waste of time.A major rework of the menu governor would be required to addressthese issues and the performance of at least some workloads (tunedspecifically to the current behavior of the menu governor) is likelyto suffer from that. It is thus better to introduce an entirely newgovernor without them and let everybody use the governor that worksbetter with their actual workloads.The new governor introduced here, the timer events oriented (TEO)governor, uses the same basic strategy as menu: it always tries tofind the deepest idle state that can be used in the given conditions.However, it applies a different approach to that problem.First, it doesn't use "correction factors" for the time till theclosest timer, but instead it tries to correlate the measured idleduration values with the available idle states and use thatinformation to pick up the idle state that is most likely to "match"the upcoming CPU idle interval.Second, it doesn't take the number of "I/O waiters" into account atall and the pattern detection code in it avoids taking timer wakeupsinto account. It also only uses idle duration values less than thecurrent time till the closest timer (with the tick excluded) for thatpurpose.Signed-off-by: Rafael J. Wysocki Acked-by: Daniel Lezcano List of files: /linux-6.15/drivers/cpuidle/governors/Makefile

4f86d3a8 - cpuidle: consolidate 2.6.22 cpuidle branch into one patch

Wed, 03 Oct 2007 22:58:00 +0000

cpuidle: consolidate 2.6.22 cpuidle branch into one patchcommit e5a16b1f9eec0af7cfa0830304b41c1c0833cf9fAuthor: Len Brown Date: Tue Oct 2 23:44:44 2007 -0400 cpuidle: shrink diff processor_idle.c | 440 +++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 429 insertions(+), 11 deletions(-) Signed-off-by: Len Brown commit dfbb9d5aedfb18848a3e0d6f6e3e4969febb209cAuthor: Len Brown Date: Wed Sep 26 02:17:55 2007 -0400 cpuidle: reduce diff size Reduces the cpuidle processor_idle.c diff vs 2.6.22 from this processor_idle.c | 2006 ++++++++++++++++++++++++++----------------- 1 file changed, 1219 insertions(+), 787 deletions(-) to this: processor_idle.c | 502 +++++++++++++++++++++++++++++++++++++++---- 1 file changed, 458 insertions(+), 44 deletions(-) ...for the purpose of making the cpuilde patch less invasive and easier to review. no functional changes. build tested only. Signed-off-by: Len Brown commit 889172fc915f5a7fe20f35b133cbd205ce69bf6cAuthor: Venki Pallipadi Date: Thu Sep 13 13:40:05 2007 -0700 cpuidle: Retain old ACPI policy for !CONFIG_CPU_IDLE Retain the old policy in processor_idle, so that when CPU_IDLE is not configured, old C-state policy will still be used. This provides a clean gradual migration path from old ACPI policy to new cpuidle based policy. Signed-off-by: Venkatesh Pallipadi Signed-off-by: Len Brown commit 9544a8181edc7ecc33b3bfd69271571f98ed08bcAuthor: Venki Pallipadi Date: Thu Sep 13 13:39:17 2007 -0700 cpuidle: Configure governors by default Quoting Len "Do not give an option to users to shoot themselves in the foot". Remove the configurability of ladder and menu governors as they are needed for default policy of cpuidle. That way users will not be able to have cpuidle without any policy loosing all C-state power savings. Signed-off-by: Venkatesh Pallipadi Signed-off-by: Len Brown commit 8975059a2c1e56cfe83d1bcf031bcf4cb39be743Author: Adam Belay Date: Tue Aug 21 18:27:07 2007 -0400 CPUIDLE: load ACPI properly when CPUIDLE is disabled Change the registration return codes for when CPUIDLE support is not compiled into the kernel. As a result, the ACPI processor driver will load properly even if CPUIDLE is unavailable. However, it may be possible to cleanup the ACPI processor driver further and eliminate some dead code paths. Signed-off-by: Adam Belay Acked-by: Venkatesh Pallipadi Signed-off-by: Len Brown commit e0322e2b58dd1b12ec669bf84693efe0dc2414a8Author: Adam Belay Date: Tue Aug 21 18:26:06 2007 -0400 CPUIDLE: remove cpuidle_get_bm_activity() Remove cpuidle_get_bm_activity() and updates governors accordingly. Signed-off-by: Adam Belay Acked-by: Venkatesh Pallipadi Signed-off-by: Len Brown commit 18a6e770d5c82ba26653e53d240caa617e09e9abAuthor: Adam Belay Date: Tue Aug 21 18:25:58 2007 -0400 CPUIDLE: max_cstate fix Currently max_cstate is limited to 0, resulting in no idle processor power management on ACPI platforms. This patch restores the value to the array size. Signed-off-by: Adam Belay Acked-by: Venkatesh Pallipadi Signed-off-by: Len Brown commit 1fdc0887286179b40ce24bcdbde663172e205ef0Author: Adam Belay Date: Tue Aug 21 18:25:40 2007 -0400 CPUIDLE: handle BM detection inside the ACPI Processor driver Update the ACPI processor driver to detect BM activity and limit state entry depth internally, rather than exposing such requirements to CPUIDLE. As a result, CPUIDLE can drop this ACPI-specific interface and become more platform independent. BM activity is now handled much more aggressively than it was in the original implementation, so some testing coverage may be needed to verify that this doesn't introduce any DMA buffer under-run issues. Signed-off-by: Adam Belay Acked-by: Venkatesh Pallipadi Signed-off-by: Len Brown commit 0ef38840db666f48e3cdd2b769da676c57228dd9Author: Adam Belay Date: Tue Aug 21 18:25:14 2007 -0400 CPUIDLE: menu governor updates Tweak the menu governor to more effectively handle non-timer break events. Non-timer break events are detected by comparing the actual sleep time to the expected sleep time. In future revisions, it may be more reliable to use the timer data structures directly. Signed-off-by: Adam Belay Acked-by: Venkatesh Pallipadi Signed-off-by: Len Brown commit bb4d74fca63fa96cf3ace644b15ae0f12b7df5a1Author: Adam Belay Date: Tue Aug 21 18:24:40 2007 -0400 CPUIDLE: fix 'current_governor' sysfs entry Allow the "current_governor" sysfs entry to properly handle input terminated with '\n'. Signed-off-by: Adam Belay Acked-by: Venkatesh Pallipadi Signed-off-by: Len Brown commit df3c71559bb69b125f1a48971bf0d17f78bbdf47Author: Len Brown Date: Sun Aug 12 02:00:45 2007 -0400 cpuidle: fix IA64 build (again) Signed-off-by: Len Brown commit a02064579e3f9530fd31baae16b1fc46b5a7bca8Author: Venkatesh Pallipadi Date: Sun Aug 12 01:39:27 2007 -0400 cpuidle: Remove support for runtime changing of max_cstate Remove support for runtime changeability of max_cstate. Drivers can use use latency APIs. max_cstate can still be used as a boot time option and dmi override. Signed-off-by: Venkatesh Pallipadi Signed-off-by: Len Brown commit 0912a44b13adf22f5e3f607d263aed23b4910d7eAuthor: Venkatesh Pallipadi Date: Sun Aug 12 01:39:16 2007 -0400 cpuidle: Remove ACPI cstate_limit calls from ipw2100 ipw2100 already has code to use accetable_latency interfaces to limit the C-state. Remove the calls to acpi_set_cstate_limit and acpi_get_cstate_limit as they are redundant. Signed-off-by: Venkatesh Pallipadi Signed-off-by: Len Brown commit c649a76e76be6bff1fd770d0a775798813a3f6e0Author: Venkatesh Pallipadi Date: Sun Aug 12 01:35:39 2007 -0400 cpuidle: compile fix for pause and resume functions Fix the compilation failure when cpuidle is not compiled in. Signed-off-by: Venkatesh Pallipadi Acked-by: Adam Belay Signed-off-by: Len Brown commit 2305a5920fb8ee6ccec1c62ade05aa8351091d71Author: Adam Belay Date: Thu Jul 19 00:49:00 2007 -0400 cpuidle: re-write Some portions have been rewritten to make the code cleaner and lighter weight. The following is a list of changes: 1.) the state name is now included in the sysfs interface 2.) detection, hotplug, and available state modifications are handled by CPUIDLE drivers directly 3.) the CPUIDLE idle handler is only ever installed when at least one cpuidle_device is enabled and ready 4.) the menu governor BM code no longer overflows 5.) the sysfs attributes are now printed as unsigned integers, avoiding negative values 6.) a variety of other small cleanups Also, Idle drivers are no longer swappable during runtime through the CPUIDLE sysfs inteface. On i386 and x86_64 most idle handlers (e.g. poll, mwait, halt, etc.) don't benefit from an infrastructure that supports multiple states, so I think using a more general case idle handler selection mechanism would be cleaner. Signed-off-by: Adam Belay Acked-by: Venkatesh Pallipadi Acked-by: Shaohua Li Signed-off-by: Len Brown commit df25b6b56955714e6e24b574d88d1fd11f0c3ee5Author: Len Brown Date: Tue Jul 24 17:08:21 2007 -0400 cpuidle: fix IA64 buid Signed-off-by: Len Brown commit fd6ada4c14488755ff7068860078c437431fbccdAuthor: Adrian Bunk Date: Mon Jul 9 11:33:13 2007 -0700 cpuidle: static make cpuidle_replace_governor() static Signed-off-by: Adrian Bunk Cc: Venkatesh Pallipadi Signed-off-by: Andrew Morton Signed-off-by: Len Brown commit c1d4a2cebcadf2429c0c72e1d29aa2a9684c32e0Author: Adrian Bunk Date: Tue Jul 3 00:54:40 2007 -0400 cpuidle: static This patch makes the needlessly global struct menu_governor static. Signed-off-by: Adrian Bunk Signed-off-by: Andrew Morton Signed-off-by: Len Brown commit dbf8780c6e8d572c2c273da97ed1cca7608fd999Author: Andrew Morton Date: Tue Jul 3 00:49:14 2007 -0400 export symbol tick_nohz_get_sleep_length ERROR: "tick_nohz_get_sleep_length" [drivers/cpuidle/governors/menu.ko] undefined! ERROR: "tick_nohz_get_idle_jiffies" [drivers/cpuidle/governors/menu.ko] undefined! And please be sure to get your changes to core kernel suitably reviewed. Cc: Adam Belay Cc: Venki Pallipadi Cc: Ingo Molnar Cc: Thomas Gleixner Cc: john stultz Signed-off-by: Andrew Morton Signed-off-by: Len Brown commit 29f0e248e7017be15f99febf9143a2cef00b2961Author: Andrew Morton Date: Tue Jul 3 00:43:04 2007 -0400 tick.h needs hrtimer.h It uses hrtimers. Signed-off-by: Andrew Morton Signed-off-by: Len Brown commit e40cede7d63a029e92712a3fe02faee60cc38fb4Author: Venki Pallipadi Date: Tue Jul 3 00:40:34 2007 -0400 cpuidle: first round of documentation updates Documentation changes based on Pavel's feedback. Signed-off-by: Venkatesh Pallipadi Signed-off-by: Andrew Morton Signed-off-by: Len Brown commit 83b42be2efece386976507555c29e7773a0dfcd1Author: Venki Pallipadi Date: Tue Jul 3 00:39:25 2007 -0400 cpuidle: add rating to the governors and pick the one with highest rating by default Introduce a governor rating scheme to pick the right governor by default. Signed-off-by: Venkatesh Pallipadi Signed-off-by: Andrew Morton Signed-off-by: Len Brown commit d2a74b8c5e8f22def4709330d4bfc4a29209b71cAuthor: Venki Pallipadi Date: Tue Jul 3 00:38:08 2007 -0400 cpuidle: make cpuidle sysfs driver governor switch off by default Make default cpuidle sysfs to show current_governor and current_driver in read-only mode. More elaborate available_governors and available_drivers with writeable current_governor and current_driver interface only appear with "cpuidle_sysfs_switch" boot parameter. Signed-off-by: Venkatesh Pallipadi Signed-off-by: Andrew Morton Signed-off-by: Len Brown commit 1f60a0e80bf83cf6b55c8845bbe5596ed8f6307bAuthor: Venki Pallipadi Date: Tue Jul 3 00:37:00 2007 -0400 cpuidle: menu governor: change the early break condition Change the C-state early break out algorithm in menu governor. We only look at early breakouts that result in wakeups shorter than idle state's target_residency. If such a breakout is frequent enough, eliminate the particular idle state upto a timeout period. Signed-off-by: Venkatesh Pallipadi Signed-off-by: Andrew Morton Signed-off-by: Len Brown commit 45a42095cf64b003b4a69be3ce7f434f97d7af51Author: Venki Pallipadi Date: Tue Jul 3 00:35:38 2007 -0400 cpuidle: fix uninitialized variable in sysfs routine Fix the uninitialized usage of ret. Signed-off-by: Venkatesh Pallipadi Signed-off-by: Andrew Morton Signed-off-by: Len Brown commit 80dca7cdba3e6ee13eae277660873ab9584eb3beAuthor: Venki Pallipadi Date: Tue Jul 3 00:34:16 2007 -0400 cpuidle: reenable /proc/acpi//power interface for the time being Keep /proc/acpi/processor/CPU*/power around for a while as powertop depends on it. It will be marked deprecated and removed in future. powertop can use cpuidle interfaces instead. Signed-off-by: Venkatesh Pallipadi Signed-off-by: Andrew Morton Signed-off-by: Len Brown commit 589c37c2646c5e3813a51255a5ee1159cb4c33fcAuthor: Venki Pallipadi Date: Tue Jul 3 00:32:37 2007 -0400 cpuidle: menu governor and hrtimer compile fix Compile fix for menu governor. Signed-off-by: Venkatesh Pallipadi Signed-off-by: Andrew Morton Signed-off-by: Len Brown commit 0ba80bd9ab3ed304cb4f19b722e4cc6740588b5eAuthor: Len Brown Date: Thu May 31 22:51:43 2007 -0400 cpuidle: build fix - cpuidle vs ipw2100 module ERROR: "acpi_set_cstate_limit" [drivers/net/wireless/ipw2100.ko] undefined! Signed-off-by: Len Brown commit d7d8fa7f96a7f7682be7c6cc0cc53fa7a18c3b58Author: Adam Belay Date: Sat Mar 24 03:47:07 2007 -0400 cpuidle: add the 'menu' governor Here is my first take at implementing an idle PM governor that takes full advantage of NO_HZ. I call it the 'menu' governor because it considers the full list of idle states before each entry. I've kept the implementation fairly simple. It attempts to guess the next residency time and then chooses a state that would meet at least the break-even point between power savings and entry cost. To this end, it selects the deepest idle state that satisfies the following constraints: 1. If the idle time elapsed since bus master activity was detected is below a threshold (currently 20 ms), then limit the selection to C2-type or above. 2. Do not choose a state with a break-even residency that exceeds the expected time remaining until the next timer interrupt. 3. Do not choose a state with a break-even residency that exceeds the elapsed time between the last pair of break events, excluding timer interrupts. This governor has an advantage over "ladder" governor because it proactively checks how much time remains until the next timer interrupt using the tick infrastructure. Also, it handles device interrupt activity more intelligently by not including timer interrupts in break event calculations. Finally, it doesn't make policy decisions using the number of state entries, which can have variable residency times (NO_HZ makes these potentially very large), and instead only considers sleep time deltas. The menu governor can be selected during runtime using the cpuidle sysfs interface like so: "echo "menu" > /sys/devices/system/cpu/cpuidle/current_governor" Signed-off-by: Adam Belay Signed-off-by: Len Brown commit a4bec7e65aa3b7488b879d971651cc99a6c410feAuthor: Adam Belay Date: Sat Mar 24 03:47:03 2007 -0400 cpuidle: export time until next timer interrupt using NO_HZ Expose information about the time remaining until the next timer interrupt expires by utilizing the dynticks infrastructure. Also modify the main idle loop to allow dynticks to handle non-interrupt break events (e.g. DMA). Finally, expose sleep ticks information to external code. Thomas Gleixner is responsible for much of the code in this patch. However, I've made some additional changes, so I'm probably responsible if there are any bugs or oversights :) Signed-off-by: Adam Belay Signed-off-by: Len Brown commit 2929d8996fbc77f41a5ff86bb67cdde3ca7d2d72Author: Adam Belay Date: Sat Mar 24 03:46:58 2007 -0400 cpuidle: governor API changes This patch prepares cpuidle for the menu governor. It adds an optional stage after idle state entry to give the governor an opportunity to check why the state was exited. Also it makes sure the idle loop returns after each state entry, allowing the appropriate dynticks code to run. Signed-off-by: Adam Belay Signed-off-by: Len Brown commit 3a7fd42f9825c3b03e364ca59baa751bb350775fAuthor: Venki Pallipadi Date: Thu Apr 26 00:03:59 2007 -0700 cpuidle: hang fix Prevent hang on x86-64, when ACPI processor driver is added as a module on a system that does not support C-states. x86-64 expects all idle handlers to enable interrupts before returning from idle handler. This is due to enter_idle(), exit_idle() races. Make cpuidle_idle_call() confirm to this when there is no pm_idle_old. Also, cpuidle look at the return values of attch_driver() and set current_driver to NULL if attach fails on all CPUs. Signed-off-by: Venkatesh Pallipadi Signed-off-by: Andrew Morton Signed-off-by: Len Brown commit 4893339a142afbd5b7c01ffadfd53d14746e858eAuthor: Shaohua Li Date: Thu Apr 26 10:40:09 2007 +0800 cpuidle: add support for max_cstate limit With CPUIDLE framework, the max_cstate (to limit max cpu c-state) parameter is ingored. Some systems require it to ignore C2/C3 and some drivers like ipw require it too. Signed-off-by: Shaohua Li Signed-off-by: Len Brown commit 43bbbbe1cb998cbd2df656f55bb3bfe30f30e7d1Author: Shaohua Li Date: Thu Apr 26 10:40:13 2007 +0800 cpuidle: add cpuidle_fore_redetect_devices API add cpuidle_force_redetect_devices API, which forces all CPU redetect idle states. Next patch will use it. Signed-off-by: Shaohua Li Signed-off-by: Len Brown commit d1edadd608f24836def5ec483d2edccfb37b1d19Author: Shaohua Li Date: Thu Apr 26 10:40:01 2007 +0800 cpuidle: fix sysfs related issue Fix the cpuidle sysfs issue. a. make kobject dynamicaly allocated b. fixed sysfs init issue to avoid suspend/resume issue Signed-off-by: Shaohua Li Signed-off-by: Len Brown commit 7169a5cc0d67b263978859672e86c13c23a5570dAuthor: Randy Dunlap Date: Wed Mar 28 22:52:53 2007 -0400 cpuidle: 1-bit field must be unsigned A 1-bit bitfield has no room for a sign bit. drivers/cpuidle/governors/ladder.c:54:16: error: dubious bitfield without explicit `signed' or `unsigned' Signed-off-by: Randy Dunlap Cc: Venkatesh Pallipadi Signed-off-by: Andrew Morton Signed-off-by: Len Brown commit 4658620158dc2fbd9e4bcb213c5b6fb5d05ba7d4Author: Venkatesh Pallipadi Date: Wed Mar 28 22:52:41 2007 -0400 cpuidle: fix boot hang Patch for cpuidle boot hang reported by Larry Finger here. http://www.ussg.iu.edu/hypermail/linux/kernel/0703.2/2025.html Signed-off-by: Venkatesh Pallipadi Cc: Larry Finger Signed-off-by: Andrew Morton Signed-off-by: Len Brown commit c17e168aa6e5fe3851baaae8df2fbc1cf11443a9Author: Len Brown Date: Wed Mar 7 04:37:53 2007 -0500 cpuidle: ladder does not depend on ACPI build fix for CONFIG_ACPI=n In file included from drivers/cpuidle/governors/ladder.c:21: include/acpi/processor.h:88: error: expected specifier-qualifier-list before â€˜acpi_integerâ€™ include/acpi/processor.h:106: error: expected specifier-qualifier-list before â€˜acpi_integerâ€™ include/acpi/processor.h:168: error: expected specifier-qualifier-list before â€˜acpi_handleâ€™ Signed-off-by: Len Brown commit 8c91d958246bde68db0c3f0c57b535962ce861cbAuthor: Adrian Bunk Date: Tue Mar 6 02:29:40 2007 -0800 cpuidle: make code static This patch makes the following needlessly global code static: - driver.c: __cpuidle_find_driver() - governor.c: __cpuidle_find_governor() - ladder.c: struct ladder_governor Signed-off-by: Adrian Bunk Cc: Venkatesh Pallipadi Cc: Adam Belay Cc: Shaohua Li Signed-off-by: Andrew Morton Signed-off-by: Len Brown commit 0c39dc3187094c72c33ab65a64d2017b21f372d2Author: Venkatesh Pallipadi Date: Wed Mar 7 02:38:22 2007 -0500 cpu_idle: fix build break This patch fixes a build breakage with !CONFIG_HOTPLUG_CPU and CONFIG_CPU_IDLE. Signed-off-by: Venkatesh Pallipadi Signed-off-by: Adrian Bunk Signed-off-by: Andrew Morton Signed-off-by: Len Brown commit 8112e3b115659b07df340ef170515799c0105f82Author: Venkatesh Pallipadi Date: Tue Mar 6 02:29:39 2007 -0800 cpuidle: build fix for !CPU_IDLE Fix the compile issues when CPU_IDLE is not configured. Signed-off-by: Venkatesh Pallipadi Cc: Adam Belay Cc: Shaohua Li Signed-off-by: Andrew Morton Signed-off-by: Len Brown commit 1eb4431e9599cd25e0d9872f3c2c8986821839ddAuthor: Venkatesh Pallipadi Date: Thu Feb 22 13:54:57 2007 -0800 cpuidle take2: Basic documentation for cpuidle Documentation for cpuidle infrastructure Signed-off-by: Venkatesh Pallipadi Signed-off-by: Adam Belay Signed-off-by: Shaohua Li Signed-off-by: Len Brown commit ef5f15a8b79123a047285ec2e3899108661df779Author: Venkatesh Pallipadi Date: Thu Feb 22 13:54:03 2007 -0800 cpuidle take2: Hookup ACPI C-states driver with cpuidle Hookup ACPI C-states onto generic cpuidle infrastructure. drivers/acpi/procesor_idle.c is now a ACPI C-states driver that registers as a driver in cpuidle infrastructure and the policy part is removed from drivers/acpi/processor_idle.c. We use governor in cpuidle instead. Signed-off-by: Shaohua Li Signed-off-by: Venkatesh Pallipadi Signed-off-by: Adam Belay Signed-off-by: Len Brown commit 987196fa82d4db52c407e8c9d5dec884ba602183Author: Venkatesh Pallipadi Date: Thu Feb 22 13:52:57 2007 -0800 cpuidle take2: Core cpuidle infrastructure Announcing 'cpuidle', a new CPU power management infrastructure to manage idle CPUs in a clean and efficient manner. cpuidle separates out the drivers that can provide support for multiple types of idle states and policy governors that decide on what idle state to use at run time. A cpuidle driver can support multiple idle states based on parameters like varying power consumption, wakeup latency, etc (ACPI C-states for example). A cpuidle governor can be usage model specific (laptop, server, laptop on battery etc). Main advantage of the infrastructure being, it allows independent development of drivers and governors and allows for better CPU power management. A huge thanks to Adam Belay and Shaohua Li who were part of this mini-project since its beginning and are greatly responsible for this patchset. This patch: Core cpuidle infrastructure. Introduces a new abstraction layer for cpuidle: * which manages drivers that can support multiple idles states. Drivers can be generic or particular to specific hardware/platform * allows pluging in multiple policy governors that can take idle state policy decision * The core also has a set of sysfs interfaces with which administrato can know about supported drivers and governors and switch them at run time. Signed-off-by: Adam Belay Signed-off-by: Shaohua Li Signed-off-by: Venkatesh Pallipadi Signed-off-by: Len Brown Signed-off-by: Len Brown List of files: /linux-6.15/drivers/cpuidle/governors/Makefile

Changes in Makefile

2cffe9f6 - cpuidle: add haltpoll governor

ec8f24b7 - treewide: Add SPDX license identifier - Makefile/Kconfig

b26bf6ab - cpuidle: New timer events oriented governor for tickless systems

4f86d3a8 - cpuidle: consolidate 2.6.22 cpuidle branch into one patch