| Message ID | 20201208164145.19493-1-daniel.lezcano@linaro.org (mailing list archive) |
|---|---|
| Headers | show |
| Series | powercap/dtpm: Add the DTPM framework | expand |
Hi Rafael, I believe I took into account all the comments, do you think it is possible to merge this series ? On 08/12/2020 17:41, Daniel Lezcano wrote: > The density of components greatly increased the last decade bringing a > numerous number of heating sources which are monitored by more than 20 > sensors on recent SoC. The skin temperature, which is the case > temperature of the device, must stay below approximately 45°C in order > to comply with the legal requirements. > > The skin temperature is managed as a whole by an user space daemon, > which is catching the current application profile, to allocate a power > budget to the different components where the resulting heating effect > will comply with the skin temperature constraint. > > This technique is called the Dynamic Thermal Power Management. > > The Linux kernel does not provide any unified interface to act on the > power of the different devices. Currently, the thermal framework is > changed to export artificially the performance states of different > devices via the cooling device software component with opaque values. > This change is done regardless of the in-kernel logic to mitigate the > temperature. The user space daemon uses all the available knobs to act > on the power limit and those differ from one platform to another. > > This series provides a Dynamic Thermal Power Management framework to > provide an unified way to act on the power of the devices. > > Changelog: > V5: > - Fixed typos in documentation > - Added a dtpm NULL pointer check in the dtpm_register() function > V4: > - Changed fine grain spinlocks by global tree mutex lock > - Dropped tested by tag from Lukasz > - Fixed rollback routine in dtpm_cpu > - Checked freq_qos_request_active() when releasing the dtpm_cpu node > V3: > - Fixed power-limit computation in addition with the hotplugging > - Improved the encapsulation > - Added specific ops for the leaves of the tree > - Simplified API and self-encapsulation > - Fixed documentation and generated it to check the content > V2: > - Fixed indentation > - Fixed typos in comments > - Fixed missing kfree for dtpm_cpu > - Capitalize letters in the Kconfig description > - Reduced name description > - Stringified section name > - Added more debug traces in the code > - Removed duplicate initialization in the dtpm cpu > > Daniel Lezcano (4): > units: Add Watt units > Documentation/powercap/dtpm: Add documentation for dtpm > powercap/drivers/dtpm: Add API for dynamic thermal power management > powercap/drivers/dtpm: Add CPU energy model based support > > Documentation/power/index.rst | 1 + > Documentation/power/powercap/dtpm.rst | 212 ++++++++++++ > drivers/powercap/Kconfig | 13 + > drivers/powercap/Makefile | 2 + > drivers/powercap/dtpm.c | 473 ++++++++++++++++++++++++++ > drivers/powercap/dtpm_cpu.c | 257 ++++++++++++++ > include/asm-generic/vmlinux.lds.h | 11 + > include/linux/cpuhotplug.h | 1 + > include/linux/dtpm.h | 77 +++++ > include/linux/units.h | 4 + > 10 files changed, 1051 insertions(+) > create mode 100644 Documentation/power/powercap/dtpm.rst > create mode 100644 drivers/powercap/dtpm.c > create mode 100644 drivers/powercap/dtpm_cpu.c > create mode 100644 include/linux/dtpm.h > > Cc: Thara Gopinath <thara.gopinath@linaro.org> > Cc: Lina Iyer <ilina@codeaurora.org> > Cc: Ram Chandrasekar <rkumbako@codeaurora.org> > Cc: Zhang Rui <rui.zhang@intel.com> > Cc: Lukasz Luba <lukasz.luba@arm.com> > > -- > 2.17.1 >
On Fri, Dec 11, 2020 at 11:41 AM Daniel Lezcano <daniel.lezcano@linaro.org> wrote: > > > Hi Rafael, > > I believe I took into account all the comments, do you think it is > possible to merge this series ? It should be, unless more changes are requested. I will be taking care of it next week and, if all goes well, it should be possible to push it during the second half of the merge window. Thanks!
On Fri, Dec 11, 2020 at 8:15 PM Rafael J. Wysocki <rafael@kernel.org> wrote: > > On Fri, Dec 11, 2020 at 11:41 AM Daniel Lezcano > <daniel.lezcano@linaro.org> wrote: > > > > > > Hi Rafael, > > > > I believe I took into account all the comments, do you think it is > > possible to merge this series ? > > It should be, unless more changes are requested. > > I will be taking care of it next week and, if all goes well, it should > be possible to push it during the second half of the merge window. Applied as 5.11-rc material now, sorry for the delay. Thanks!
On 22/12/2020 19:52, Rafael J. Wysocki wrote: > On Fri, Dec 11, 2020 at 8:15 PM Rafael J. Wysocki <rafael@kernel.org> wrote: >> >> On Fri, Dec 11, 2020 at 11:41 AM Daniel Lezcano >> <daniel.lezcano@linaro.org> wrote: >>> >>> >>> Hi Rafael, >>> >>> I believe I took into account all the comments, do you think it is >>> possible to merge this series ? >> >> It should be, unless more changes are requested. >> >> I will be taking care of it next week and, if all goes well, it should >> be possible to push it during the second half of the merge window. > > Applied as 5.11-rc material now, sorry for the delay. No problem, thank you for taking care of the series. I did not want to add another entry in the MAINTAINER file as you are the maintainer of the powercap framework and that is fine. However the get_maintainer script (and default cccmd) does not return me as part of the maintainer/author of the dtpm or idle_inject. I would like to be at least Cc'ed to review the changes related to those files to make sure they stay aligned with the direction we are taking. Is it possible to be automatically Cc'ed for the proposed changes in these files ?
Hi! > The density of components greatly increased the last decade bringing a > numerous number of heating sources which are monitored by more than 20 > sensors on recent SoC. The skin temperature, which is the case > temperature of the device, must stay below approximately 45°C in order > to comply with the legal requirements. What kind of device is that? Does that mean that running fsck is now "illegal" because temperature will not be managed during that time? Pavel
On 24/12/2020 19:46, Pavel Machek wrote: > Hi! > >> The density of components greatly increased the last decade bringing a >> numerous number of heating sources which are monitored by more than 20 >> sensors on recent SoC. The skin temperature, which is the case >> temperature of the device, must stay below approximately 45°C in order >> to comply with the legal requirements. > > What kind of device is that? Any complex embedded devices like a phone, a laptop or a tablet with components like NPU, CPU, GPU, GPS, DSPs, Camera, ... > Does that mean that running fsck is now "illegal" because temperature > will not be managed during that time? The heating effect of the different devices will be conducted through a common dissipation device. The 'skin' temperature or 'case' temperature has a dedicated sensor in the path of this dissipation device. So the temperature will increase slower at this sensor level because of a higher thermal capacity. The 'skin' temperature will be the result of the different components running at the same time (eg. GPS + CPU + GPU + DSPs). In the case of fsck, the system is in degraded mode, thus the application using these components are not supposed to run and the 'skin' temperature should stay below. If you are interested, here you can find some background to explain the 'skin' temperature [1] and the spreading of the heat [2]. Hope that helps -- Daniel [1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4188373/ [2] https://nanoheat.stanford.edu/sites/default/files/publications/Electronics%20Cooling%20Article.pdf
The density of components greatly increased the last decade bringing a numerous number of heating sources which are monitored by more than 20 sensors on recent SoC. The skin temperature, which is the case temperature of the device, must stay below approximately 45°C in order to comply with the legal requirements. The skin temperature is managed as a whole by an user space daemon, which is catching the current application profile, to allocate a power budget to the different components where the resulting heating effect will comply with the skin temperature constraint. This technique is called the Dynamic Thermal Power Management. The Linux kernel does not provide any unified interface to act on the power of the different devices. Currently, the thermal framework is changed to export artificially the performance states of different devices via the cooling device software component with opaque values. This change is done regardless of the in-kernel logic to mitigate the temperature. The user space daemon uses all the available knobs to act on the power limit and those differ from one platform to another. This series provides a Dynamic Thermal Power Management framework to provide an unified way to act on the power of the devices. Changelog: V5: - Fixed typos in documentation - Added a dtpm NULL pointer check in the dtpm_register() function V4: - Changed fine grain spinlocks by global tree mutex lock - Dropped tested by tag from Lukasz - Fixed rollback routine in dtpm_cpu - Checked freq_qos_request_active() when releasing the dtpm_cpu node V3: - Fixed power-limit computation in addition with the hotplugging - Improved the encapsulation - Added specific ops for the leaves of the tree - Simplified API and self-encapsulation - Fixed documentation and generated it to check the content V2: - Fixed indentation - Fixed typos in comments - Fixed missing kfree for dtpm_cpu - Capitalize letters in the Kconfig description - Reduced name description - Stringified section name - Added more debug traces in the code - Removed duplicate initialization in the dtpm cpu Daniel Lezcano (4): units: Add Watt units Documentation/powercap/dtpm: Add documentation for dtpm powercap/drivers/dtpm: Add API for dynamic thermal power management powercap/drivers/dtpm: Add CPU energy model based support Documentation/power/index.rst | 1 + Documentation/power/powercap/dtpm.rst | 212 ++++++++++++ drivers/powercap/Kconfig | 13 + drivers/powercap/Makefile | 2 + drivers/powercap/dtpm.c | 473 ++++++++++++++++++++++++++ drivers/powercap/dtpm_cpu.c | 257 ++++++++++++++ include/asm-generic/vmlinux.lds.h | 11 + include/linux/cpuhotplug.h | 1 + include/linux/dtpm.h | 77 +++++ include/linux/units.h | 4 + 10 files changed, 1051 insertions(+) create mode 100644 Documentation/power/powercap/dtpm.rst create mode 100644 drivers/powercap/dtpm.c create mode 100644 drivers/powercap/dtpm_cpu.c create mode 100644 include/linux/dtpm.h Cc: Thara Gopinath <thara.gopinath@linaro.org> Cc: Lina Iyer <ilina@codeaurora.org> Cc: Ram Chandrasekar <rkumbako@codeaurora.org> Cc: Zhang Rui <rui.zhang@intel.com> Cc: Lukasz Luba <lukasz.luba@arm.com> -- 2.17.1