kernel.git/drivers/cpuidle/poll_state.c, branch linux-6.4.y

cpuidle: Fix poll_idle() noinstr annotation

2023-01-31T14:01:47Z

The instrumentation_begin()/end() annotations in poll_idle() were complete nonsense. Specifically they caused tracing to happen in the middle of noinstr code, resulting in RCU splats. Now that local_clock() is noinstr, mark up the rest and let it rip. Fixes: 00717eb8c955 ("cpuidle: Annotate poll_idle()") Reported-by: kernel test robot Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Acked-by: Rafael J. Wysocki Link: https://lore.kernel.org/oe-lkp/202301192148.58ece903-oliver.sang@intel.com Link: https://lore.kernel.org/r/20230126151323.819534689@infradead.org

cpuidle: Annotate poll_idle()

2023-01-13T10:48:15Z

The __cpuidle functions will become a noinstr class, as such they need explicit annotations. Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Tested-by: Tony Lindgren Tested-by: Ulf Hansson Reviewed-by: Rafael J. Wysocki Acked-by: Frederic Weisbecker Link: https://lore.kernel.org/r/20230112195540.312601331@infradead.org

cpuidle/poll: Ensure IRQs stay disabled after cpuidle_state::enter() calls

2023-01-13T10:03:21Z

Make cpuidle_state::enter() methods IRQ state invariant on exit. Additionally make sure to use raw_local_irq_*() methods since this cpuidle callback will be called with RCU already disabled. Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Tested-by: Tony Lindgren Tested-by: Ulf Hansson Reviewed-by: Rafael J. Wysocki Reviewed-by: Frederic Weisbecker Link: https://lore.kernel.org/r/20230112195539.515253662@infradead.org

cpuidle: Drop disabled field from struct cpuidle_state

2019-11-29T10:48:39Z

After recent cpuidle updates the "disabled" field in struct cpuidle_state is only used by two drivers (intel_idle and shmobile cpuidle) for marking unusable idle states, but that may as well be achieved with the help of a state flag, so define an "unusable" idle state flag, CPUIDLE_FLAG_UNUSABLE, make the drivers in question use it instead of the "disabled" field and make the core set CPUIDLE_STATE_DISABLED_BY_DRIVER for the idle states with that flag set. After the above changes, the "disabled" field in struct cpuidle_state is not used any more, so drop it. No intentional functional impact. Signed-off-by: Rafael J. Wysocki

cpuidle: Use nanoseconds as the unit of time

2019-11-11T20:56:07Z

Currently, the cpuidle subsystem uses microseconds as the unit of time which (among other things) causes the idle loop to incur some integer division overhead for no clear benefit. In order to allow cpuidle to measure time in nanoseconds, add two new fields, exit_latency_ns and target_residency_ns, to represent the exit latency and target residency of an idle state in nanoseconds, respectively, to struct cpuidle_state and initialize them with the help of the corresponding values in microseconds provided by drivers. Additionally, change cpuidle_governor_latency_req() to return the idle state exit latency constraint in nanoseconds. Also meeasure idle state residency (last_residency_ns in struct cpuidle_device and time_ns in struct cpuidle_driver) in nanoseconds and update the cpuidle core and governors accordingly. However, the menu governor still computes typical intervals in microseconds to avoid integer overflows. Signed-off-by: Rafael J. Wysocki Acked-by: Peter Zijlstra (Intel) Acked-by: Doug Smythies Tested-by: Doug Smythies

cpuidle: add poll_limit_ns to cpuidle_device structure

2019-07-30T15:27:37Z

Add a poll_limit_ns variable to cpuidle_device structure. Calculate and configure it in the new cpuidle_poll_time function, in case its zero. Individual governors are allowed to override this value. Signed-off-by: Marcelo Tosatti Signed-off-by: Rafael J. Wysocki

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 428

2019-06-05T15:37:16Z

Based on 1 normalized pattern(s): this file is released under the gplv2 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 68 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Armijn Hemel Reviewed-by: Allison Randal Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190531190114.292346262@linutronix.de Signed-off-by: Greg Kroah-Hartman

cpuidle: poll_state: Fix default time limit

2019-01-30T21:57:42Z

The default time is declared in units of microsecnds, but is used as nanoseconds, resulting in significant accounting errors for idle state 0 time when all idle states deeper than 0 are disabled. Under these unusual conditions, we don't really care about the poll time limit anyhow. Fixes: 800fb34a99ce ("cpuidle: poll_state: Disregard disable idle states") Signed-off-by: Doug Smythies Signed-off-by: Rafael J. Wysocki

cpuidle: poll_state: Disregard disable idle states

2018-12-11T11:07:07Z

When computing the limit of time to spend in the loop in poll_idle(), use the target residency of the first enabled idle state deeper than state 0 instead of always using the target residency of state 1. This helps when state 1 is disabled for diagnostics, for instance. Signed-off-by: Rafael J. Wysocki

cpuidle: poll_state: Revise loop termination condition

2018-10-04T17:27:27Z

If need_resched() returns "false", breaking out of the loop in poll_idle() will cause a new idle state to be selected, so in fact it usually doesn't make sense to spin in it longer than the target residency of the second state. [Note that the "polling" state is used only if there is at least one "real" state defined in addition to it, so the second state is always there.] On the other hand, breaking out of it early (say in case the next state is disabled) shouldn't hurt as it is polling anyway. For this reason, make the loop in poll_idle() break if the CPU has been spinning longer than the target residency of the second state (the "polling" state can only be state[0]). Signed-off-by: Rafael J. Wysocki