kernel/linux.git/drivers/cpuidle/sysfs.c, branch v4.17.1

PM: cpuidle/suspend: Add s2idle usage and time state attributes

2018-03-29T11:06:08+00:00

Add a new attribute group called "s2idle" under the sysfs directory of each cpuidle state that supports the ->enter_s2idle callback and put two new attributes, "usage" and "time", into that group to represent the number of times the given state was requested for suspend-to-idle and the total time spent in suspend-to-idle after requesting that state, respectively. That will allow diagnostic information related to suspend-to-idle to be collected without enabling advanced debug features and analyzing dmesg output. Signed-off-by: Rafael J. Wysocki

cpuidle: Validate cpu_dev in cpuidle_add_sysfs()

2017-03-21T21:26:37+00:00

If a given cpu is not in cpu_present and cpu hotplug is disabled, arch can skip setting up the cpu_dev. Arch cpuidle driver should pass correct cpu mask for registration, but failing to do so by the driver causes error to propagate and crash like this: [ 30.076045] Unable to handle kernel paging request for data at address 0x00000048 [ 30.076100] Faulting instruction address: 0xc0000000007b2f30 cpu 0x4d: Vector: 300 (Data Access) at [c000003feb18b670] pc: c0000000007b2f30: kobject_get+0x20/0x70 lr: c0000000007b3c94: kobject_add_internal+0x54/0x3f0 sp: c000003feb18b8f0 msr: 9000000000009033 dar: 48 dsisr: 40000000 current = 0xc000003fd2ed8300 paca = 0xc00000000fbab500 softe: 0 irq_happened: 0x01 pid = 1, comm = swapper/0 Linux version 4.11.0-rc2-svaidy+ (sv@sagarika) (gcc version 6.2.0 20161005 (Ubuntu 6.2.0-5ubuntu12) ) #10 SMP Sun Mar 19 00:08:09 IST 2017 enter ? for help [c000003feb18b960] c0000000007b3c94 kobject_add_internal+0x54/0x3f0 [c000003feb18b9f0] c0000000007b43a4 kobject_init_and_add+0x64/0xa0 [c000003feb18ba70] c000000000e284f4 cpuidle_add_sysfs+0xb4/0x130 [c000003feb18baf0] c000000000e26038 cpuidle_register_device+0x118/0x1c0 [c000003feb18bb30] c000000000e26c48 cpuidle_register+0x78/0x120 [c000003feb18bbc0] c00000000168fd9c powernv_processor_idle_init+0x110/0x1c4 [c000003feb18bc40] c00000000000cff8 do_one_initcall+0x68/0x1d0 [c000003feb18bd00] c0000000016242f4 kernel_init_freeable+0x280/0x360 [c000003feb18bdc0] c00000000000d864 kernel_init+0x24/0x160 [c000003feb18be30] c00000000000b4e8 ret_from_kernel_thread+0x5c/0x74 Validating cpu_dev fixes the crash and reports correct error message like: [ 30.163506] Failed to register cpuidle device for cpu136 [ 30.173329] Registration of powernv driver failed. Signed-off-by: Vaidyanathan Srinivasan [ rjw: Comment massage ] Signed-off-by: Rafael J. Wysocki

cpuidle: fix improper return value on error

2016-12-06T01:24:14+00:00

In function cpuidle_add_state_sysfs(), variable ret takes the return value. Its value should be negative on errors. Because ret is reset in the loop, its value will be 0 during the second and after repeat of the loop. If kzalloc() returns a NULL pointer then, it will return 0. It may be better to explicitly assign "-ENOMEM" when the call to kzalloc() fails. Link: https://bugzilla.kernel.org/show_bug.cgi?id=188901 Signed-off-by: Pan Bian Signed-off-by: Rafael J. Wysocki

cpuidle: remove state_count field from struct cpuidle_device

2015-04-03T11:15:50+00:00

Thomas Schlichter reports the following issue on his Samsung NC20: "The C-states C1 and C2 to the OS when connected to AC, and additionally provides the C3 C-state when disconnected from AC. However, the number of C-states shown in sysfs is fixed to the number of C-states present at boot. If I boot with AC connected, I always only see the C-states up to C2 even if I disconnect AC. The reason is commit 130a5f692425 (ACPI / cpuidle: remove dev->state_count setting). It removes the update of dev->state_count, but sysfs uses exactly this variable to show the C-states. The fix is to use drv->state_count in sysfs. As this is currently the last user of dev->state_count, this variable can be completely removed." Remove dev->state_count as per the above. Reported-by: Thomas Schlichter Signed-off-by: Bartlomiej Zolnierkiewicz Signed-off-by: Kyungmin Park Acked-by: Daniel Lezcano Cc: 3.14+ # 3.14+ [ rjw: Changelog ] Signed-off-by: Rafael J. Wysocki

cpuidle: fix permission for driver name sysfs node

2014-07-19T19:43:28+00:00

cpuidle driver name sysfs node is read-only, so permissions should be 0444. Signed-off-by: Mohammad Merajul Islam Molla Signed-off-by: Rafael J. Wysocki

cpuidle: sysfs: Export target residency information

2014-04-08T10:37:05+00:00

From user space, there is no way to know the target residency for each idle state. If we want to write tools to measure the accuracy of the idle state selection from the governor, we need this info. As the exit latency is exported through sysfs, exporting the target residency in the same place makes sense. Signed-off-by: Daniel Lezcano Signed-off-by: Rafael J. Wysocki

cpuidle: use drv instead of cpuidle_driver in show_current_driver()

2013-10-30T00:21:23+00:00

Instances of "struct cpuidle_driver *" are consistently named as "drv" in the cpuidle core except in show_current_driver(). Make that function use variable naming consistent with the rest of the code. [rjw: Changelog] Acked-by: Daniel Lezcano Signed-off-by: Viresh Kumar Signed-off-by: Rafael J. Wysocki

cpuidle: call cpuidle_get_driver() from after taking cpuidle_driver_lock

2013-10-30T00:21:23+00:00

There are a few cpuidle_get_driver() calls that aren't made under cpuidle_driver_lock which is incorrect. Fix them by calling cpuidle_get_driver() after taking cpuidle_driver_lock. Acked-by: Daniel Lezcano Signed-off-by: Viresh Kumar Signed-off-by: Rafael J. Wysocki

cpuidle: Make cpuidle's sysfs directory dynamically allocated

2013-07-15T00:09:47+00:00

The cpuidle sysfs code is designed to have a single instance of per CPU cpuidle directory. It is not possible to remove the sysfs entry and create it again. This is not a problem with the current code but future changes will add CPU hotplug support to enable/disable the device, so it will need to remove the sysfs entry like other subsystems do. That won't be possible without this change, because the kobj is a static object which can't be reused for kobj_init_and_add(). Add cpuidle_device_kobj to be allocated dynamically when adding/removing a sysfs entry which is consistent with the other cpuidle's sysfs entries. An added benefit is that the sysfs code is now more self-contained and the includes needed for sysfs can be moved from cpuidle.h directly into sysfs.c so as to reduce the total number of headers dragged along with cpuidle.h. [rjw: Changelog] Signed-off-by: Daniel Lezcano Signed-off-by: Rafael J. Wysocki

cpuidle: Fix white space to follow CodingStyle

2013-07-15T00:09:47+00:00

Fix white space in the cpuidle code to follow the rules described in CodingStyle. No changes in behavior should result from this. [rjw: Changelog] Signed-off-by: Daniel Lezcano Signed-off-by: Rafael J. Wysocki