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Rename two local variables in teo_select() so that their names better
reflect their purpose.
No functional impact.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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There are three mistakes in the loop in teo_select() that is looking
for an alternative candidate idle state. First, it should walk all
of the idle states shallower than the current candidate one,
including all of the disabled ones, but it terminates after the first
enabled idle state. Second, it should not terminate its last step
if idle state 0 is disabled (which is related to the first issue).
Finally, it may return the current alternative candidate idle state
prematurely if the time span criterion is not met by the idle state
under consideration at the moment.
To address the issues mentioned above, make the loop in question walk
all of the idle states shallower than the current candidate idle state
all the way down to idle state 0 and rearrange the checks in it.
Fixes: 77577558f25d ("cpuidle: teo: Rework most recent idle duration values treatment")
Reported-by: Doug Smythies <dsmythies@telus.net>
Tested-by: Doug Smythies <dsmythies@telus.net>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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https://git.linaro.org/people/daniel.lezcano/linux
Pull ARM cpuidle updates for v5.14 from Daniel Lezcano:
"- Add support for Qcom MSM8226 (Bartosz Dudziak)"
* tag 'cpuidle-v5.14-rc1' of https://git.linaro.org/people/daniel.lezcano/linux:
cpuidle: qcom: Add SPM register data for MSM8226
dt-bindings: arm: msm: Add SAW2 for MSM8226
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git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management updates from Rafael Wysocki:
"These add hybrid processors support to the intel_pstate driver and
make it work with more processor models when HWP is disabled, make the
intel_idle driver use special C6 idle state paremeters when package
C-states are disabled, add cooling support to the tegra30 devfreq
driver, rework the TEO (timer events oriented) cpuidle governor,
extend the OPP (operating performance points) framework to use the
required-opps DT property in more cases, fix some issues and clean up
a number of assorted pieces of code.
Specifics:
- Make intel_pstate support hybrid processors using abstract
performance units in the HWP interface (Rafael Wysocki).
- Add Icelake servers and Cometlake support in no-HWP mode to
intel_pstate (Giovanni Gherdovich).
- Make cpufreq_online() error path be consistent with the CPU device
removal path in cpufreq (Rafael Wysocki).
- Clean up 3 cpufreq drivers and the statistics code (Hailong Liu,
Randy Dunlap, Shaokun Zhang).
- Make intel_idle use special idle state parameters for C6 when
package C-states are disabled (Chen Yu).
- Rework the TEO (timer events oriented) cpuidle governor to address
some theoretical shortcomings in it (Rafael Wysocki).
- Drop unneeded semicolon from the TEO governor (Wan Jiabing).
- Modify the runtime PM framework to accept unassigned suspend and
resume callback pointers (Ulf Hansson).
- Improve pm_runtime_get_sync() documentation (Krzysztof Kozlowski).
- Improve device performance states support in the generic power
domains (genpd) framework (Ulf Hansson).
- Fix some documentation issues in genpd (Yang Yingliang).
- Make the operating performance points (OPP) framework use the
required-opps DT property in use cases that are not related to
genpd (Hsin-Yi Wang).
- Make lazy_link_required_opp_table() use list_del_init instead of
list_del/INIT_LIST_HEAD (Yang Yingliang).
- Simplify wake IRQs handling in the core system-wide sleep support
code and clean up some coding style inconsistencies in it (Tian
Tao, Zhen Lei).
- Add cooling support to the tegra30 devfreq driver and improve its
DT bindings (Dmitry Osipenko).
- Fix some assorted issues in the devfreq core and drivers (Chanwoo
Choi, Dong Aisheng, YueHaibing)"
* tag 'pm-5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (39 commits)
PM / devfreq: passive: Fix get_target_freq when not using required-opp
cpufreq: Make cpufreq_online() call driver->offline() on errors
opp: Allow required-opps to be used for non genpd use cases
cpuidle: teo: remove unneeded semicolon in teo_select()
dt-bindings: devfreq: tegra30-actmon: Add cooling-cells
dt-bindings: devfreq: tegra30-actmon: Convert to schema
PM / devfreq: userspace: Use DEVICE_ATTR_RW macro
PM: runtime: Clarify documentation when callbacks are unassigned
PM: runtime: Allow unassigned ->runtime_suspend|resume callbacks
PM: runtime: Improve path in rpm_idle() when no callback
PM: hibernate: remove leading spaces before tabs
PM: sleep: remove trailing spaces and tabs
PM: domains: Drop/restore performance state votes for devices at runtime PM
PM: domains: Return early if perf state is already set for the device
PM: domains: Split code in dev_pm_genpd_set_performance_state()
cpuidle: teo: Use kerneldoc documentation in admin-guide
cpuidle: teo: Rework most recent idle duration values treatment
cpuidle: teo: Change the main idle state selection logic
cpuidle: teo: Cosmetic modification of teo_select()
cpuidle: teo: Cosmetic modifications of teo_update()
...
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Fix following coccicheck warning:
drivers/cpuidle/governors/teo.c:315:10-11: Unneeded semicolon
Signed-off-by: Wan Jiabing <wanjiabing@vivo.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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Add MSM8226 register data to SPM AVS Wrapper 2 (SAW2) power controller
driver.
Reviewed-by: Stephan Gerhold <stephan@gerhold.net>
Signed-off-by: Bartosz Dudziak <bartosz.dudziak@snejp.pl>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20210612205335.9730-3-bartosz.dudziak@snejp.pl
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There are two descriptions of the TEO (Timer Events Oriented) cpuidle
governor in the kernel source tree, one in the C file containing its
code and one in cpuidle.rst which is part of admin-guide.
Instead of trying to keep them both in sync and in order to reduce
text duplication, include the governor description from the C file
directly into cpuidle.rst.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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The TEO (Timer Events Oriented) cpuidle governor uses several most
recent idle duration values for a given CPU to refine the idle state
selection in case the previous long-term trends have not been
followed recently and a new trend appears to be forming. That is
done by computing the average of the most recent idle duration
values falling below the time till the next timer event ("sleep
length"), provided that they are the majority of the most recent
idle duration values taken into account, and using it as the new
expected idle duration value.
However, idle state selection based on that value may not be optimal,
because the average does not really indicate which of the idle states
with target residencies less than or equal to it is likely to be the
best fit.
Thus, instead of computing the average, make the governor carry out
computations based on the distribution of the most recent idle
duration values among the bins corresponding to different idle
states. Namely, if the majority of the most recent idle duration
values taken into consideration are less than the current sleep
length (which means that the CPU is likely to wake up early), find
the idle state closest to the "candidate" one "matching" the sleep
length whose target residency is less than or equal to the majority
of the most recent idle duration values that have fallen below the
current sleep length (which means that it is likely to be "shallow
enough" this time).
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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Two aspects of the current main idle state selection logic in the
TEO (Timer Events Oriented) cpuidle governor are quite questionable.
First of all, the "hits" and "misses" metrics used by it are only
updated for a given idle state if the time till the next timer event
("sleep length") is between the target residency of that state and
the target residency of the next one. Consequently, they are likely
to become stale if the sleep length tends to fall outside that
interval which increases the likelihood of subomtimal idle state
selection.
Second, the decision on whether or not to select the idle state
"matching" the sleep length is based on the metrics collected for
that state alone, whereas in principle the metrics collected for
the other idle states should be taken into consideration when that
decision is made. For example, if the measured idle duration is less
than the target residency of the idle state "matching" the sleep
length, then it is also less than the target residency of any deeper
idle state and that should be taken into account when considering
whether or not to select any of those states, but currently it is
not.
In order to address the above shortcomings, modify the main idle
state selection logic in the TEO governor to take the metrics
collected for all of the idle states into account when deciding
whether or not to select the one "matching" the sleep length.
Moreover, drop the "misses" metric that becomes redundant after the
above change and rename the "early_hits" metric to "intercepts" so
that its role is better reflected by its name (the idea being that
if a CPU wakes up earlier than indicated by the sleep length, then
it must be a result of a non-timer interrupt that "intercepts" the
CPU).
Also rename the states[] array in struct struct teo_cpu to
state_bins[] to avoid confusing it with the states[] array in
struct cpuidle_driver and update the documentation to match the
new code (and make it more comprehensive while at it).
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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Initialize local variables in teo_select() where they are declared.
No functional impact.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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Rename a local variable in teo_update() so that its purpose is better
reflected by its name and use one more local variable in the loop
over the CPU idle states in that function to make the code somewhat
easier to read.
No functional impact.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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Runqueue ->nr_iowait counters are 32-bit anyway.
Propagate 32-bitness into other code, but don't try too hard.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210422200228.1423391-3-adobriyan@gmail.com
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When CONFIG_ARM_QCOM_SPM_CPUIDLE is y and CONFIG_MMU is not set,
compiling errors are encountered as follows:
drivers/cpuidle/cpuidle-qcom-spm.o: In function `spm_dev_probe':
cpuidle-qcom-spm.c:(.text+0x140): undefined reference to `cpu_resume_arm'
cpuidle-qcom-spm.c:(.text+0x148): undefined reference to `cpu_resume_arm'
Note that cpu_resume_arm is defined when MMU is set. So, add dependency
on MMU in ARM_QCOM_SPM_CPUIDLE configuration.
Fixes: a871be6b8eee ("cpuidle: Convert Qualcomm SPM driver to a generic CPUidle driver")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: He Ying <heying24@huawei.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20210406123328.92904-1-heying24@huawei.com
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The do_idle firmware call is unused by all Tegra SoCs, hence remove it in
order to keep driver's code clean.
Tested-by: Anton Bambura <jenneron@protonmail.com> # TF701 T114
Tested-by: Matt Merhar <mattmerhar@protonmail.com> # Ouya T30
Tested-by: Peter Geis <pgwipeout@gmail.com> # Ouya T30
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Reviewed-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20210302095405.28453-2-digetx@gmail.com
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Trusted Foundation firmware doesn't implement the do_idle call and in
this case suspending should fall back to the common suspend path. In order
to fix this issue we will unconditionally set the NOFLUSH_L2 mode via
firmware call, which is a NO-OP on Tegra30/124, and then proceed to the
C7 idling, like it was done by the older Tegra114 cpuidle driver.
Fixes: 14e086baca50 ("cpuidle: tegra: Squash Tegra114 driver into the common driver")
Cc: stable@vger.kernel.org # 5.7+
Reported-by: Anton Bambura <jenneron@protonmail.com> # TF701 T114
Tested-by: Anton Bambura <jenneron@protonmail.com> # TF701 T114
Tested-by: Matt Merhar <mattmerhar@protonmail.com> # Ouya T30
Tested-by: Peter Geis <pgwipeout@gmail.com> # Ouya T30
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Reviewed-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20210302095405.28453-1-digetx@gmail.com
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Make the menu governor check the tick_nohz_get_next_hrtimer()
return value so as to avoid dealing with negative "sleep length"
values and make it use that value directly when the tick is stopped.
While at it, rename local variable delta_next in menu_select() to
delta_tick which better reflects its purpose.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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Modify the TEO governor to take possible negative return values of
tick_nohz_get_next_hrtimer() into account by changing the data type
of some variables used by it to s64 which allows it to carry out
computations without potentially problematic data type conversions
into u64.
Also change the computations in teo_select() so that the negative
values themselves are handled in a natural way to avoid adding extra
negative value checks to that function.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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If the time till the next timer event is shorter than the target
residency of the first idle state (state 0), the TEO governor does
not update its metrics for any idle states, but arguably it should
record a "hit" for idle state 0 in that case, so modify it to do
that.
Accordingly, also make it record an "early hit" for idle state 0 if
the measured idle duration is less than its target residency, which
allows one branch more to be dropped from teo_update().
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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Subsequent changes will cause the exit_latency_ns and target_residency_ns
fields in struct cpuidle_state to be used in computations in which data
type conversions to u64 may turn a negative number close to zero into
a verly large positive number leading to incorrect results.
In preparation for that, change the data type of the fields mentioned
above to s64, but ensure that they will not be negative themselves.
No intentional functional impact.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc
Pull ARM SoC driver updates from Arnd Bergmann:
"There are a couple of subsystems maintained by other people that merge
their drivers through the SoC tree, those changes include:
- The SCMI firmware framework gains support for sensor notifications
and for controlling voltage domains.
- A large update for the Tegra memory controller driver, integrating
it better with the interconnect framework
- The memory controller subsystem gains support for Mediatek MT8192
- The reset controller framework gains support for sharing pulsed
resets
For Soc specific drivers in drivers/soc, the main changes are
- The Allwinner/sunxi MBUS gets a rework for the way it handles
dma_map_ops and offsets between physical and dma address spaces.
- An errata fix plus some cleanups for Freescale Layerscape SoCs
- A cleanup for renesas drivers regarding MMIO accesses.
- New SoC specific drivers for Mediatek MT8192 and MT8183 power
domains
- New SoC specific drivers for Aspeed AST2600 LPC bus control and SoC
identification.
- Core Power Domain support for Qualcomm MSM8916, MSM8939, SDM660 and
SDX55.
- A rework of the TI AM33xx 'genpd' power domain support to use
information from DT instead of platform data
- Support for TI AM64x SoCs
- Allow building some Amlogic drivers as modules instead of built-in
Finally, there are numerous cleanups and smaller bug fixes for
Mediatek, Tegra, Samsung, Qualcomm, TI OMAP, Amlogic, Rockchips,
Renesas, and Xilinx SoCs"
* tag 'arm-soc-drivers-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (222 commits)
soc: mediatek: mmsys: Specify HAS_IOMEM dependency for MTK_MMSYS
firmware: xilinx: Properly align function parameter
firmware: xilinx: Add a blank line after function declaration
firmware: xilinx: Remove additional newline
firmware: xilinx: Fix kernel-doc warnings
firmware: xlnx-zynqmp: fix compilation warning
soc: xilinx: vcu: add missing register NUM_CORE
soc: xilinx: vcu: use vcu-settings syscon registers
dt-bindings: soc: xlnx: extract xlnx, vcu-settings to separate binding
soc: xilinx: vcu: drop useless success message
clk: samsung: mark PM functions as __maybe_unused
soc: samsung: exynos-chipid: initialize later - with arch_initcall
soc: samsung: exynos-chipid: order list of SoCs by name
memory: jz4780_nemc: Fix potential NULL dereference in jz4780_nemc_probe()
memory: ti-emif-sram: only build for ARMv7
memory: tegra30: Support interconnect framework
memory: tegra20: Support hardware versioning and clean up OPP table initialization
dt-bindings: memory: tegra20-emc: Document opp-supported-hw property
soc: rockchip: io-domain: Fix error return code in rockchip_iodomain_probe()
reset-controller: ti: force the write operation when assert or deassert
...
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git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management updates from Rafael Wysocki:
"These update cpufreq (core and drivers), cpuidle (polling state
implementation and the PSCI driver), the OPP (operating performance
points) framework, devfreq (core and drivers), the power capping RAPL
(Running Average Power Limit) driver, the Energy Model support, the
generic power domains (genpd) framework, the ACPI device power
management, the core system-wide suspend code and power management
utilities.
Specifics:
- Use local_clock() instead of jiffies in the cpufreq statistics to
improve accuracy (Viresh Kumar).
- Fix up OPP usage in the cpufreq-dt and qcom-cpufreq-nvmem cpufreq
drivers (Viresh Kumar).
- Clean up the cpufreq core, the intel_pstate driver and the
schedutil cpufreq governor (Rafael Wysocki).
- Fix up error code paths in the sti-cpufreq and mediatek cpufreq
drivers (Yangtao Li, Qinglang Miao).
- Fix cpufreq_online() to return error codes instead of success (0)
in all cases when it fails (Wang ShaoBo).
- Add mt8167 support to the mediatek cpufreq driver and blacklist
mt8516 in the cpufreq-dt-platdev driver (Fabien Parent).
- Modify the tegra194 cpufreq driver to always return values from the
frequency table as the current frequency and clean up that driver
(Sumit Gupta, Jon Hunter).
- Modify the arm_scmi cpufreq driver to allow it to discover the
power scale present in the performance protocol and provide this
information to the Energy Model (Lukasz Luba).
- Add missing MODULE_DEVICE_TABLE to several cpufreq drivers (Pali
Rohár).
- Clean up the CPPC cpufreq driver (Ionela Voinescu).
- Fix NVMEM_IMX_OCOTP dependency in the imx cpufreq driver (Arnd
Bergmann).
- Rework the poling interval selection for the polling state in
cpuidle (Mel Gorman).
- Enable suspend-to-idle for PSCI OSI mode in the PSCI cpuidle driver
(Ulf Hansson).
- Modify the OPP framework to support empty (node-less) OPP tables in
DT for passing dependency information (Nicola Mazzucato).
- Fix potential lockdep issue in the OPP core and clean up the OPP
core (Viresh Kumar).
- Modify dev_pm_opp_put_regulators() to accept a NULL argument and
update its users accordingly (Viresh Kumar).
- Add frequency changes tracepoint to devfreq (Matthias Kaehlcke).
- Add support for governor feature flags to devfreq, make devfreq
sysfs file permissions depend on the governor and clean up the
devfreq core (Chanwoo Choi).
- Clean up the tegra20 devfreq driver and deprecate it to allow
another driver based on EMC_STAT to be used instead of it (Dmitry
Osipenko).
- Add interconnect support to the tegra30 devfreq driver, allow it to
take the interconnect and OPP information from DT and clean it up
(Dmitry Osipenko).
- Add interconnect support to the exynos-bus devfreq driver along
with interconnect properties documentation (Sylwester Nawrocki).
- Add suport for AMD Fam17h and Fam19h processors to the RAPL power
capping driver (Victor Ding, Kim Phillips).
- Fix handling of overly long constraint names in the powercap
framework (Lukasz Luba).
- Fix the wakeup configuration handling for bridges in the ACPI
device power management core (Rafael Wysocki).
- Add support for using an abstract scale for power units in the
Energy Model (EM) and document it (Lukasz Luba).
- Add em_cpu_energy() micro-optimization to the EM (Pavankumar
Kondeti).
- Modify the generic power domains (genpd) framwework to support
suspend-to-idle (Ulf Hansson).
- Fix creation of debugfs nodes in genpd (Thierry Strudel).
- Clean up genpd (Lina Iyer).
- Clean up the core system-wide suspend code and make it print driver
flags for devices with debug enabled (Alex Shi, Patrice Chotard,
Chen Yu).
- Modify the ACPI system reboot code to make it prepare for system
power off to avoid confusing the platform firmware (Kai-Heng Feng).
- Update the pm-graph (multiple changes, mostly usability-related)
and cpupower (online and offline CPU information support) PM
utilities (Todd Brandt, Brahadambal Srinivasan)"
* tag 'pm-5.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (86 commits)
cpufreq: Fix cpufreq_online() return value on errors
cpufreq: Fix up several kerneldoc comments
cpufreq: stats: Use local_clock() instead of jiffies
cpufreq: schedutil: Simplify sugov_update_next_freq()
cpufreq: intel_pstate: Simplify intel_cpufreq_update_pstate()
PM: domains: create debugfs nodes when adding power domains
opp: of: Allow empty opp-table with opp-shared
dt-bindings: opp: Allow empty OPP tables
media: venus: dev_pm_opp_put_*() accepts NULL argument
drm/panfrost: dev_pm_opp_put_*() accepts NULL argument
drm/lima: dev_pm_opp_put_*() accepts NULL argument
PM / devfreq: exynos: dev_pm_opp_put_*() accepts NULL argument
cpufreq: qcom-cpufreq-nvmem: dev_pm_opp_put_*() accepts NULL argument
cpufreq: dt: dev_pm_opp_put_regulators() accepts NULL argument
opp: Allow dev_pm_opp_put_*() APIs to accept NULL opp_table
opp: Don't create an OPP table from dev_pm_opp_get_opp_table()
cpufreq: dt: Don't (ab)use dev_pm_opp_get_opp_table() to create OPP table
opp: Reduce the size of critical section in _opp_kref_release()
PM / EM: Micro optimization in em_cpu_energy
cpufreq: arm_scmi: Discover the power scale in performance protocol
...
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residency
It was noted that a few workloads that idle rapidly regressed when commit
36fcb4292473 ("cpuidle: use first valid target residency as poll time")
was merged. The workloads in question were heavy communicators that idle
rapidly and were impacted by the c-state exit latency as the active CPUs
were not polling at the time of wakeup. As they were not particularly
realistic workloads, it was not considered to be a major problem.
Unfortunately, a bug was reported for a real workload in a production
environment that relied on large numbers of threads operating in a worker
pool pattern. These threads would idle for periods of time longer than the
C1 target residency and so incurred the c-state exit latency penalty. The
application is very sensitive to wakeup latency and indirectly relying
on behaviour prior to commit on a37b969a61c1 ("cpuidle: poll_state: Add
time limit to poll_idle()") to poll for long enough to avoid the exit
latency cost.
The target residency of C1 is typically very short. On some x86 machines,
it can be as low as 2 microseconds. In poll_idle(), the clock is checked
every POLL_IDLE_RELAX_COUNT interations of cpu_relax() and even one
iteration of that loop can be over 1 microsecond so the polling interval is
very close to the granularity of what poll_idle() can detect. Furthermore,
a basic ping pong workload like perf bench pipe has a longer round-trip
time than the 2 microseconds meaning that the CPU will almost certainly
not be polling when the ping-pong completes.
This patch selects a polling interval based on an enabled c-state that
has an target residency longer than 10usec. If there is no enabled-cstate
then polling will be up to a TICK_NSEC/16 similar to what it was up until
kernel 4.20. Polling for a full tick is unlikely (rescheduling event)
and is much longer than the existing target residencies for a deep c-state.
As an example, consider a CPU with the following c-state information from
an Intel CPU;
residency exit_latency
C1 2 2
C1E 20 10
C3 100 33
C6 400 133
The polling interval selected is 20usec. If booted with
intel_idle.max_cstate=1 then the polling interval is 250usec as the deeper
c-states were not available.
On an AMD EPYC machine, the c-state information is more limited and
looks like
residency exit_latency
C1 2 1
C2 800 400
The polling interval selected is 250usec. While C2 was considered, the
polling interval was clamped by CPUIDLE_POLL_MAX.
Note that it is not expected that polling will be a universal win. As
well as potentially trading power for performance, the performance is not
guaranteed if the extra polling prevented a turbo state being reached.
Making it a tunable was considered but it's driver-specific, may be
overridden by a governor and is not a guaranteed polling interval making
it difficult to describe without knowledge of the implementation.
tbench4
vanilla polling
Hmean 1 497.89 ( 0.00%) 543.15 * 9.09%*
Hmean 2 975.88 ( 0.00%) 1059.73 * 8.59%*
Hmean 4 1953.97 ( 0.00%) 2081.37 * 6.52%*
Hmean 8 3645.76 ( 0.00%) 4052.95 * 11.17%*
Hmean 16 6882.21 ( 0.00%) 6995.93 * 1.65%*
Hmean 32 10752.20 ( 0.00%) 10731.53 * -0.19%*
Hmean 64 12875.08 ( 0.00%) 12478.13 * -3.08%*
Hmean 128 21500.54 ( 0.00%) 21098.60 * -1.87%*
Hmean 256 21253.70 ( 0.00%) 21027.18 * -1.07%*
Hmean 320 20813.50 ( 0.00%) 20580.64 * -1.12%*
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
|
|
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
Get rid of the __call_single_node union and cleanup the API a little
to avoid external code relying on the structure layout as much.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
|
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Annotate tegra_pm_set[clear]_cpu_in_lp2() with RCU_NONIDLE in order to
fix lockdep warning about suspicious RCU usage of a spinlock during late
idling phase.
WARNING: suspicious RCU usage
...
include/trace/events/lock.h:13 suspicious rcu_dereference_check() usage!
...
(dump_stack) from (lock_acquire)
(lock_acquire) from (_raw_spin_lock)
(_raw_spin_lock) from (tegra_pm_set_cpu_in_lp2)
(tegra_pm_set_cpu_in_lp2) from (tegra_cpuidle_enter)
(tegra_cpuidle_enter) from (cpuidle_enter_state)
(cpuidle_enter_state) from (cpuidle_enter_state_coupled)
(cpuidle_enter_state_coupled) from (cpuidle_enter)
(cpuidle_enter) from (do_idle)
...
Tested-by: Peter Geis <pgwipeout@gmail.com>
Reported-by: Peter Geis <pgwipeout@gmail.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
|
|
To select domain idlestates for cpuidle-psci when OSI mode has been
enabled, the PM domains via genpd are being managed through runtime PM.
This works fine for the regular idlepath, but it doesn't during system wide
suspend. More precisely, the domain idlestates becomes temporarily
disabled, which is because the PM core disables runtime PM for devices
during system wide suspend.
Later in the system suspend phase, genpd intends to deal with this from its
->suspend_noirq() callback, but this doesn't work as expected for a device
corresponding to a CPU, because the domain idlestates needs to be selected
on a per CPU basis (the PM core doesn't invoke the callbacks like that).
To address this problem, let's enable the syscore flag for the
corresponding CPU device that becomes successfully attached to its PM
domain (applicable only in OSI mode). This informs the PM core to skip
invoke the system wide suspend/resume callbacks for the device, thus also
prevents genpd from screwing up its internal state of it.
Moreover, to properly select a domain idlestate for the CPUs during
suspend-to-idle, let's assign a specific ->enter_s2idle() callback for the
corresponding domain idlestate (applicable only in OSI mode). From that
callback, let's invoke dev_pm_genpd_suspend|resume(), as this allows a
domain idlestate to be selected for the current CPU by genpd.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
|
|
This driver always worked properly only on the Exynos 5420/5800 based
Chromebooks (Peach-Pit/Pi), so change the required compatible string to
the 'google,peach', to avoid enabling it on the other Exynos 542x/5800
boards, which hangs in such case. The main difference between Peach-Pit/Pi
and other Exynos 542x/5800 boards is the firmware - Peach platform doesn't
use secure firmware at all.
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc updates from Michael Ellerman:
- A series from Nick adding ARCH_WANT_IRQS_OFF_ACTIVATE_MM & selecting
it for powerpc, as well as a related fix for sparc.
- Remove support for PowerPC 601.
- Some fixes for watchpoints & addition of a new ptrace flag for
detecting ISA v3.1 (Power10) watchpoint features.
- A fix for kernels using 4K pages and the hash MMU on bare metal
Power9 systems with > 16TB of RAM, or RAM on the 2nd node.
- A basic idle driver for shallow stop states on Power10.
- Tweaks to our sched domains code to better inform the scheduler about
the hardware topology on Power9/10, where two SMT4 cores can be
presented by firmware as an SMT8 core.
- A series doing further reworks & cleanups of our EEH code.
- Addition of a filter for RTAS (firmware) calls done via sys_rtas(),
to prevent root from overwriting kernel memory.
- Other smaller features, fixes & cleanups.
Thanks to: Alexey Kardashevskiy, Andrew Donnellan, Aneesh Kumar K.V,
Athira Rajeev, Biwen Li, Cameron Berkenpas, Cédric Le Goater, Christophe
Leroy, Christoph Hellwig, Colin Ian King, Daniel Axtens, David Dai, Finn
Thain, Frederic Barrat, Gautham R. Shenoy, Greg Kurz, Gustavo Romero,
Ira Weiny, Jason Yan, Joel Stanley, Jordan Niethe, Kajol Jain, Konrad
Rzeszutek Wilk, Laurent Dufour, Leonardo Bras, Liu Shixin, Luca
Ceresoli, Madhavan Srinivasan, Mahesh Salgaonkar, Nathan Lynch, Nicholas
Mc Guire, Nicholas Piggin, Nick Desaulniers, Oliver O'Halloran, Pedro
Miraglia Franco de Carvalho, Pratik Rajesh Sampat, Qian Cai, Qinglang
Miao, Ravi Bangoria, Russell Currey, Satheesh Rajendran, Scott Cheloha,
Segher Boessenkool, Srikar Dronamraju, Stan Johnson, Stephen Kitt,
Stephen Rothwell, Thiago Jung Bauermann, Tyrel Datwyler, Vaibhav Jain,
Vaidyanathan Srinivasan, Vasant Hegde, Wang Wensheng, Wolfram Sang, Yang
Yingliang, zhengbin.
* tag 'powerpc-5.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (228 commits)
Revert "powerpc/pci: unmap legacy INTx interrupts when a PHB is removed"
selftests/powerpc: Fix eeh-basic.sh exit codes
cpufreq: powernv: Fix frame-size-overflow in powernv_cpufreq_reboot_notifier
powerpc/time: Make get_tb() common to PPC32 and PPC64
powerpc/time: Make get_tbl() common to PPC32 and PPC64
powerpc/time: Remove get_tbu()
powerpc/time: Avoid using get_tbl() and get_tbu() internally
powerpc/time: Make mftb() common to PPC32 and PPC64
powerpc/time: Rename mftbl() to mftb()
powerpc/32s: Remove #ifdef CONFIG_PPC_BOOK3S_32 in head_book3s_32.S
powerpc/32s: Rename head_32.S to head_book3s_32.S
powerpc/32s: Setup the early hash table at all time.
powerpc/time: Remove ifdef in get_dec() and set_dec()
powerpc: Remove get_tb_or_rtc()
powerpc: Remove __USE_RTC()
powerpc: Tidy up a bit after removal of PowerPC 601.
powerpc: Remove support for PowerPC 601
powerpc: Remove PowerPC 601
powerpc: Drop SYNC_601() ISYNC_601() and SYNC()
powerpc: Remove CONFIG_PPC601_SYNC_FIX
...
|
|
|
|
CPUs may fail to enter the chosen idle state if there was a
pending interrupt, causing the cpuidle driver to return an error
value.
Record that and export it via sysfs along with the other idle state
statistics.
This could prove useful in understanding behavior of the governor
and the system during usecases that involve multiple CPUs.
Signed-off-by: Lina Iyer <ilina@codeaurora.org>
[ rjw: Changelog and documentation edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
|
|
The commit 1098582a0f6c ("sched,idle,rcu: Push rcu_idle deeper into the
idle path"), moved the calls rcu_idle_enter|exit() into the cpuidle core.
However, it forgot to remove a couple of comments in enter_s2idle_proper()
about why RCU_NONIDLE earlier was needed. So, let's drop them as they have
become a bit misleading.
Fixes: 1098582a0f6c ("sched,idle,rcu: Push rcu_idle deeper into the idle path")
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
|
|
If the PSCI OSI mode isn't supported or fails to be enabled, the PM domain
topology with the genpd providers isn't initialized. This is perfectly fine
from cpuidle-psci point of view.
However, since the PM domain topology in the DTS files is a description of
the HW, no matter of whether the PSCI OSI mode is supported or not, other
consumers besides the CPUs may rely on it.
Therefore, let's always allow the initialization of the PM domain topology
to succeed, independently of whether the PSCI OSI mode is supported.
Consequentially we need to track if we succeed to enable the OSI mode, as
to know when a domain idlestate can be selected.
Note that, CPU devices are still not being attached to the PM domain
topology, unless the PSCI OSI mode is supported.
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
|
|
The current user (cpuidle-psci) of psci_set_osi_mode() only needs to enable
the PSCI OSI mode. Although, as subsequent changes shows, there is a need
to be able to reset back into the PSCI PC mode.
Therefore, let's extend psci_set_osi_mode() to take a bool as in-parameter,
to let the user indicate whether to enable OSI or to switch back to PC
mode.
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
|
|
The enter() callback of CPUIDLE drivers returns index of the entered idle
state on success or a negative value on failure. The negative value could
any negative value, i.e. it doesn't necessarily needs to be a error code.
That's because CPUIDLE core only cares about the fact of failure and not
about the reason of the enter() failure.
Like every other enter() callback, the arm_cpuidle_simple_enter() returns
the entered idle-index on success. Unlike some of other drivers, it never
fails. It happened that TEGRA_C1=index=err=0 in the code of cpuidle-tegra
driver, and thus, there is no problem for the cpuidle-tegra driver created
by the typo in the code which assumes that the arm_cpuidle_simple_enter()
returns a error code.
The arm_cpuidle_simple_enter() also may return a -ENODEV error if CPU_IDLE
is disabled in a kernel's config, but all CPUIDLE drivers are disabled if
CPU_IDLE is disabled, including the cpuidle-tegra driver. So we can't ever
see the error code from arm_cpuidle_simple_enter() today.
Of course the code may get some changes in the future and then the
typo may transform into a real bug, so let's correct the typo! The
tegra_cpuidle_state_enter() is now changed to make it return the entered
idle-index on success and negative error code on fail, which puts it on
par with the arm_cpuidle_simple_enter(), making code consistent in regards
to the error handling.
This patch fixes a minor typo in the code, it doesn't fix any bugs.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Reviewed-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
|
|
The commit eb1f00237aca ("lockdep,trace: Expose tracepoints"), started to
expose us for tracepoints. This lead to the following RCU splat on an ARM64
Qcom board.
[ 5.529634] WARNING: suspicious RCU usage
[ 5.537307] sdhci-pltfm: SDHCI platform and OF driver helper
[ 5.541092] 5.9.0-rc3 #86 Not tainted
[ 5.541098] -----------------------------
[ 5.541105] ../include/trace/events/lock.h:37 suspicious rcu_dereference_check() usage!
[ 5.541110]
[ 5.541110] other info that might help us debug this:
[ 5.541110]
[ 5.541116]
[ 5.541116] rcu_scheduler_active = 2, debug_locks = 1
[ 5.541122] RCU used illegally from extended quiescent state!
[ 5.541129] no locks held by swapper/0/0.
[ 5.541134]
[ 5.541134] stack backtrace:
[ 5.541143] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.9.0-rc3 #86
[ 5.541149] Hardware name: Qualcomm Technologies, Inc. APQ 8016 SBC (DT)
[ 5.541157] Call trace:
[ 5.568185] sdhci_msm 7864900.sdhci: Got CD GPIO
[ 5.574186] dump_backtrace+0x0/0x1c8
[ 5.574206] show_stack+0x14/0x20
[ 5.574229] dump_stack+0xe8/0x154
[ 5.574250] lockdep_rcu_suspicious+0xd4/0xf8
[ 5.574269] lock_acquire+0x3f0/0x460
[ 5.574292] _raw_spin_lock_irqsave+0x80/0xb0
[ 5.574314] __pm_runtime_suspend+0x4c/0x188
[ 5.574341] psci_enter_domain_idle_state+0x40/0xa0
[ 5.574362] cpuidle_enter_state+0xc0/0x610
[ 5.646487] cpuidle_enter+0x38/0x50
[ 5.650651] call_cpuidle+0x18/0x40
[ 5.654467] do_idle+0x228/0x278
[ 5.657678] cpu_startup_entry+0x24/0x70
[ 5.661153] rest_init+0x1a4/0x278
[ 5.665061] arch_call_rest_init+0xc/0x14
[ 5.668272] start_kernel+0x508/0x540
Following the path in pm_runtime_put_sync_suspend() from
psci_enter_domain_idle_state(), it seems like we end up using the RCU.
Therefore, let's simply silence the splat by informing the RCU about it
with RCU_NONIDLE.
Note that, this is a temporary solution. Instead we should strive to avoid
using RCU_NONIDLE (and similar), but rather push rcu_idle_enter|exit()
further down, closer to the arch specific code. However, as the CPU PM
notifiers are also using the RCU, additional rework is needed.
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc fixes from Michael Ellerman:
"Some more powerpc fixes for 5.9:
- Opt us out of the DEBUG_VM_PGTABLE support for now as it's causing
crashes.
- Fix a long standing bug in our DMA mask handling that was hidden
until recently, and which caused problems with some drivers.
- Fix a boot failure on systems with large amounts of RAM, and no
hugepage support and using Radix MMU, only seen in the lab.
- A few other minor fixes.
Thanks to Alexey Kardashevskiy, Aneesh Kumar K.V, Gautham R. Shenoy,
Hari Bathini, Ira Weiny, Nick Desaulniers, Shirisha Ganta, Vaibhav
Jain, and Vaidyanathan Srinivasan"
* tag 'powerpc-5.9-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
powerpc/papr_scm: Limit the readability of 'perf_stats' sysfs attribute
cpuidle: pseries: Fix CEDE latency conversion from tb to us
powerpc/dma: Fix dma_map_ops::get_required_mask
Revert "powerpc/build: vdso linker warning for orphan sections"
powerpc/mm: Remove DEBUG_VM_PGTABLE support on powerpc
selftests/powerpc: Skip PROT_SAO test in guests/LPARS
powerpc/book3s64/radix: Fix boot failure with large amount of guest memory
|
|
Some drivers have to do significant work, some of which relies on RCU
still being active. Instead of using RCU_NONIDLE in the drivers and
flipping RCU back on, allow drivers to take over RCU-idle duty.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
|
|
This driver does not restore stop > 3 state, so it limits itself
to states which do not lose full state or TB.
The POWER10 SPRs are sufficiently different from P9 that it seems
easier to split out the P10 code. The POWER10 deep sleep code
(e.g., the BHRB restore) has been taken out, but it can be re-added
when stop > 3 support is added.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Tested-by: Pratik Rajesh Sampat<psampat@linux.ibm.com>
Tested-by: Vaidyanathan Srinivasan <svaidy@linux.ibm.com>
Reviewed-by: Pratik Rajesh Sampat<psampat@linux.ibm.com>
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200819094700.493399-1-npiggin@gmail.com
|
|
Commit d947fb4c965c ("cpuidle: pseries: Fixup exit latency for
CEDE(0)") sets the exit latency of CEDE(0) based on the latency values
of the Extended CEDE states advertised by the platform. The values
advertised by the platform are in timebase ticks. However the cpuidle
framework requires the latency values in microseconds.
If the tb-ticks value advertised by the platform correspond to a value
smaller than 1us, during the conversion from tb-ticks to microseconds,
in the current code, the result becomes zero. This is incorrect as it
puts a CEDE state on par with the snooze state.
This patch fixes this by rounding up the result obtained while
converting the latency value from tb-ticks to microseconds. It also
prints a warning in case we discover an extended-cede state with
wakeup latency to be 0. In such a case, ensure that CEDE(0) has a
non-zero wakeup latency.
Fixes: d947fb4c965c ("cpuidle: pseries: Fixup exit latency for CEDE(0)")
Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Reviewed-by: Vaidyanathan Srinivasan <svaidy@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1599125247-28488-1-git-send-email-ego@linux.vnet.ibm.com
|
|
This allows moving the leave_mm() call into generic code before
rcu_idle_enter(). Gets rid of more trace_*_rcuidle() users.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Marco Elver <elver@google.com>
Link: https://lkml.kernel.org/r/20200821085348.369441600@infradead.org
|
|
Lots of things take locks, due to a wee bug, rcu_lockdep didn't notice
that the locking tracepoints were using RCU.
Push rcu_idle_{enter,exit}() as deep as possible into the idle paths,
this also resolves a lot of _rcuidle()/RCU_NONIDLE() usage.
Specifically, sched_clock_idle_wakeup_event() will use ktime which
will use seqlocks which will tickle lockdep, and
stop_critical_timings() uses lock.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Marco Elver <elver@google.com>
Link: https://lkml.kernel.org/r/20200821085348.310943801@infradead.org
|
|
Match the pattern elsewhere in this file.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Marco Elver <elver@google.com>
Link: https://lkml.kernel.org/r/20200821085348.251340558@infradead.org
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc updates from Michael Ellerman:
- Add support for (optionally) using queued spinlocks & rwlocks.
- Support for a new faster system call ABI using the scv instruction on
Power9 or later.
- Drop support for the PROT_SAO mmap/mprotect flag as it will be
unsupported on Power10 and future processors, leaving us with no way
to implement the functionality it requests. This risks breaking
userspace, though we believe it is unused in practice.
- A bug fix for, and then the removal of, our custom stack expansion
checking. We now allow stack expansion up to the rlimit, like other
architectures.
- Remove the remnants of our (previously disabled) topology update
code, which tried to react to NUMA layout changes on virtualised
systems, but was prone to crashes and other problems.
- Add PMU support for Power10 CPUs.
- A change to our signal trampoline so that we don't unbalance the link
stack (branch return predictor) in the signal delivery path.
- Lots of other cleanups, refactorings, smaller features and so on as
usual.
Thanks to: Abhishek Goel, Alastair D'Silva, Alexander A. Klimov, Alexey
Kardashevskiy, Alistair Popple, Andrew Donnellan, Aneesh Kumar K.V, Anju
T Sudhakar, Anton Blanchard, Arnd Bergmann, Athira Rajeev, Balamuruhan
S, Bharata B Rao, Bill Wendling, Bin Meng, Cédric Le Goater, Chris
Packham, Christophe Leroy, Christoph Hellwig, Daniel Axtens, Dan
Williams, David Lamparter, Desnes A. Nunes do Rosario, Erhard F., Finn
Thain, Frederic Barrat, Ganesh Goudar, Gautham R. Shenoy, Geoff Levand,
Greg Kurz, Gustavo A. R. Silva, Hari Bathini, Harish, Imre Kaloz, Joel
Stanley, Joe Perches, John Crispin, Jordan Niethe, Kajol Jain, Kamalesh
Babulal, Kees Cook, Laurent Dufour, Leonardo Bras, Li RongQing, Madhavan
Srinivasan, Mahesh Salgaonkar, Mark Cave-Ayland, Michal Suchanek, Milton
Miller, Mimi Zohar, Murilo Opsfelder Araujo, Nathan Chancellor, Nathan
Lynch, Naveen N. Rao, Nayna Jain, Nicholas Piggin, Oliver O'Halloran,
Palmer Dabbelt, Pedro Miraglia Franco de Carvalho, Philippe Bergheaud,
Pingfan Liu, Pratik Rajesh Sampat, Qian Cai, Qinglang Miao, Randy
Dunlap, Ravi Bangoria, Sachin Sant, Sam Bobroff, Sandipan Das, Santosh
Sivaraj, Satheesh Rajendran, Shirisha Ganta, Sourabh Jain, Srikar
Dronamraju, Stan Johnson, Stephen Rothwell, Thadeu Lima de Souza
Cascardo, Thiago Jung Bauermann, Tom Lane, Vaibhav Jain, Vladis Dronov,
Wei Yongjun, Wen Xiong, YueHaibing.
* tag 'powerpc-5.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (337 commits)
selftests/powerpc: Fix pkey syscall redefinitions
powerpc: Fix circular dependency between percpu.h and mmu.h
powerpc/powernv/sriov: Fix use of uninitialised variable
selftests/powerpc: Skip vmx/vsx/tar/etc tests on older CPUs
powerpc/40x: Fix assembler warning about r0
powerpc/papr_scm: Add support for fetching nvdimm 'fuel-gauge' metric
powerpc/papr_scm: Fetch nvdimm performance stats from PHYP
cpuidle: pseries: Fixup exit latency for CEDE(0)
cpuidle: pseries: Add function to parse extended CEDE records
cpuidle: pseries: Set the latency-hint before entering CEDE
selftests/powerpc: Fix online CPU selection
powerpc/perf: Consolidate perf_callchain_user_[64|32]()
powerpc/pseries/hotplug-cpu: Remove double free in error path
powerpc/pseries/mobility: Add pr_debug() for device tree changes
powerpc/pseries/mobility: Set pr_fmt()
powerpc/cacheinfo: Warn if cache object chain becomes unordered
powerpc/cacheinfo: Improve diagnostics about malformed cache lists
powerpc/cacheinfo: Use name@unit instead of full DT path in debug messages
powerpc/cacheinfo: Set pr_fmt()
powerpc: fix function annotations to avoid section mismatch warnings with gcc-10
...
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We are currently assuming that CEDE(0) has exit latency 10us, since
there is no way for us to query from the platform. However, if the
wakeup latency of an Extended CEDE state is smaller than 10us, then we
can be sure that the exit latency of CEDE(0) cannot be more than that.
In this patch, we fix the exit latency of CEDE(0) if we discover an
Extended CEDE state with wakeup latency smaller than 10us.
Benchmark results:
On POWER8, this patch does not have any impact since the advertized
latency of Extended CEDE (1) is 30us which is higher than the default
latency of CEDE (0) which is 10us.
On POWER9 we see improvement the single-threaded performance of
ebizzy, and no regression in the wakeup latency or the number of
context-switches.
ebizzy:
2 ebizzy threads bound to the same big-core. 25% improvement in the
avg records/s with patch.
x without_patch
* with_patch
N Min Max Median Avg Stddev
x 10 2491089 5834307 5398375 4244335 1596244.9
* 10 2893813 5834474 5832448 5327281.3 1055941.4
context_switch2:
There is no major regression observed with this patch as seen from the
context_switch2 benchmark.
context_switch2 across CPU0 CPU1 (Both belong to same big-core, but
different small cores). We observe a minor 0.14% regression in the
number of context-switches (higher is better).
x without_patch
* with_patch
N Min Max Median Avg Stddev
x 500 348872 362236 354712 354745.69 2711.827
* 500 349422 361452 353942 354215.4 2576.9258
Difference at 99.0% confidence
-530.288 +/- 430.963
-0.149484% +/- 0.121485%
(Student's t, pooled s = 2645.24)
context_switch2 across CPU0 CPU8 (Different big-cores). We observe a
0.37% improvement in the number of context-switches (higher is
better).
x without_patch
* with_patch
N Min Max Median Avg Stddev
x 500 287956 294940 288896 288977.23 646.59295
* 500 288300 294646 289582 290064.76 1161.9992
Difference at 99.0% confidence
1087.53 +/- 153.194
0.376337% +/- 0.0530125%
(Student's t, pooled s = 940.299)
schbench:
No major difference could be seen until the 99.9th percentile.
Without-patch:
Latency percentiles (usec)
50.0th: 29
75.0th: 39
90.0th: 49
95.0th: 59
*99.0th: 13104
99.5th: 14672
99.9th: 15824
min=0, max=17993
With-patch:
Latency percentiles (usec)
50.0th: 29
75.0th: 40
90.0th: 50
95.0th: 61
*99.0th: 13648
99.5th: 14768
99.9th: 15664
min=0, max=29812
Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
[mpe: Minor formatting]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1596087177-30329-4-git-send-email-ego@linux.vnet.ibm.com
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Currently we use CEDE with latency-hint 0 as the only other idle state
on a dedicated LPAR apart from the polling "snooze" state.
The platform might support additional extended CEDE idle states, which
can be discovered through the "ibm,get-system-parameter" rtas-call
made with CEDE_LATENCY_TOKEN.
This patch adds a function to obtain information about the extended
CEDE idle states from the platform and parse the contents to populate
an array of extended CEDE states. These idle states thus discovered
will be added to the cpuidle framework in the next patch.
dmesg on a POWER8 and POWER9 LPAR, demonstrating the output of parsing
the extended CEDE latency parameters are as follows
POWER8
[ 10.093279] xcede : xcede_record_size = 10
[ 10.093285] xcede : Record 0 : hint = 1, latency = 0x3c00 tb ticks, Wake-on-irq = 1
[ 10.093291] xcede : Record 1 : hint = 2, latency = 0x4e2000 tb ticks, Wake-on-irq = 0
[ 10.093297] cpuidle : Skipping the 2 Extended CEDE idle states
POWER9
[ 5.913180] xcede : xcede_record_size = 10
[ 5.913183] xcede : Record 0 : hint = 1, latency = 0x400 tb ticks, Wake-on-irq = 1
[ 5.913188] xcede : Record 1 : hint = 2, latency = 0x3e8000 tb ticks, Wake-on-irq = 0
[ 5.913193] cpuidle : Skipping the 2 Extended CEDE idle states
Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
[mpe: Make space for 16 records, drop memset, minor cleanup & formatting]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1596087177-30329-3-git-send-email-ego@linux.vnet.ibm.com
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As per the PAPR, each H_CEDE call is associated with a latency-hint to
be passed in the VPA field "cede_latency_hint". The CEDE states that
we were implicitly entering so far is CEDE with latency-hint = 0.
This patch explicitly sets the latency hint corresponding to the CEDE
state that we are currently entering. While at it, we save the
previous hint, to be restored once we wakeup from CEDE. This will be
required in the future when we expose extended-cede states through the
cpuidle framework, where each of them will have a different
cede-latency hint.
Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
[mpe: Make cede_latency_hint static]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1596087177-30329-2-git-send-email-ego@linux.vnet.ibm.com
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Control Flow Integrity(CFI) is a security mechanism that disallows
changes to the original control flow graph of a compiled binary,
making it significantly harder to perform such attacks.
init_state_node() assign same function callback to different
function pointer declarations.
static int init_state_node(struct cpuidle_state *idle_state,
const struct of_device_id *matches,
struct device_node *state_node) { ...
idle_state->enter = match_id->data; ...
idle_state->enter_s2idle = match_id->data; }
Function declarations:
struct cpuidle_state { ...
int (*enter) (struct cpuidle_device *dev,
struct cpuidle_driver *drv,
int index);
void (*enter_s2idle) (struct cpuidle_device *dev,
struct cpuidle_driver *drv,
int index); };
In this case, either enter() or enter_s2idle() would cause CFI check
failed since they use same callee.
Align function prototype of enter() since it needs return value for
some use cases. The return value of enter_s2idle() is no
need currently.
Signed-off-by: Neal Liu <neal.liu@mediatek.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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Depending on the SoC/platform, additional devices may be part of the PSCI
PM domain topology. This is the case with 'qcom,rpmh-rsc' device, for
example, even if this is not yet visible in the corresponding DTS-files.
Without going into too much details, a device like the 'qcom,rpmh-rsc' may
have HW constraints that needs to be obeyed to, before a domain idlestate
can be picked.
Therefore, let's implement the ->sync_state() callback to receive a
notification when all consumers of the PSCI PM domain providers have been
attached/probed to it. In this way, we can make sure all constraints from
all relevant devices, are taken into account before allowing a domain
idlestate to be picked.
Acked-by: Saravana Kannan <saravanak@google.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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