Messages in this thread | | | Date | Mon, 19 Oct 2015 14:58:25 -0600 | From | Lina Iyer <> | Subject | Re: [RFC v2 0/6] Managing cluser-level c-states with generic power domains |
| |
Hi Marc,
I am trying to apply this on top of Axel's patches on linux-next (after fixing issues I saw with his v9), and running to issues applying your patches. Could you rebase on top of his v10 (he said he would send to the ML soon) ?
Thanks, Lina
On Tue, Oct 06 2015 at 08:27 -0600, Marc Titinger wrote: >v2: > - rebase on Lina Iyer's latest series > - remove unnecessary dependency on perf-state patches from Axel Haslam > >----------------------- > >Summary > >1) DESCRIPTION >2) DEPENDENCIES >3) URL >------------------------ > > >1) DESCRIPTION > > > This patch set's underlying idea is that cluster-level c-states can be managed >by the power domain, building upon Lina Iyers recent work on CPU-domain, and Axel Haslam's >genpd multiple states. The power domain may contain CPU devices and non-CPU devices. > >Non-CPU Devices may expose latency constraints by registering intermediate power-states upon >probing, for instance shallower states than the deepest cluster-off state. The generic >power domain governor may chose a device retention state in place of the cluster-sleep >state demanded by the menu governor, and call the platform specific handling to enter/leave >that retention state. > > >power-states >----------- > > >The proposed way how cluster-level c-states are declared as manageable by the >power domain, rather than through the cpuidle-ops, relies on the introduction of >"power-states", consistent with c-states. Here is an example of the DT bindings, >the c-state CLUSTER_SLEEP_0 is exposed as a power-state in the compatible property: > >juno.dts: idle-states { > entry-method = "arm,psci"; > > CPU_SLEEP_0: cpu-sleep-0 { > compatible = "arm,idle-state"; > arm,psci-suspend-param = <0x0010000>; > local-timer-stop; > entry-latency-us = <100>; > exit-latency-us = <250>; > min-residency-us = <2000>; > }; > > CLUSTER_SLEEP_0: cluster-sleep-0 { > compatible = "arm,power-state"; > arm,psci-suspend-param = <0x1010000>; > local-timer-stop; > entry-latency-us = <800>; > exit-latency-us = <700>; > min-residency-us = <2500>; > }; > } > >This will tell cpuidle runtime_put/get the CPU devices for this c-state. Eventually, the >actual platform handlers may be called from the genpd platform ops (in place of cpuidle_ops). > >"drivers/cpuidle/cpuidle-arm.c": > >static const struct of_device_id arm_idle_state_match[] __initconst = { > {.compatible = "arm,idle-state", > .data = arm_enter_idle_state}, > {.compatible = "arm,power-state", > .data = arm_enter_power_state}, >}; > > >In case of a power-state, arm_enter_power_state will only call pm_runtime_put/get_sync >The power doamin will handle the power off, currently this patch set lacks the final >call to the psci interface to have a fully fonctionnal setup >(and there are some genpd_lock'ing issues if put/get actually suspend the CPU device.) > >Ultimately, we would like the Power Domain's simple governor to being able to chose >the cluster power-state based on the c-states defered to it (power-states) and constraints >added by the devices. Consequently, we need to "soak" those power-states into the >power-domain intermediate states from Axel. Since power-states are declared and handled >the same manner than c-states (idle-states in DT), these patches add a soaking used when >attaching to a genpd, where power-states are parsed from the DT into the genpd states: > > >"drivers/base/power/domain.c": > >static const struct of_device_id power_state_match[] = { > {.compatible = "arm,power-state", > }, >}; > >int of_genpd_device_parse_states(struct device_node *np, > struct generic_pm_domain *genpd) > >debugfs addition >--------------- > >To easy debug, this patch set adds a seq-file names "states" to the pm_genpd debugfs: > > cat /sys/kernel/debug/pm_genpd/* > > Domain State name Enter (ns) / Exit (ns) > ------------------------------------------------------------- > a53_pd cluster-sleep-0 1500000 / 800000 > a57_pd cluster-sleep-0 1500000 / 800000 > >And also a seq-file "timings", to help visualize the constrains of the non-CPU >devices in a cluster PD. > > Domain Devices, Timings in ns > Stop/Start Save/Restore, Effective >---------------------------------------------------- --- >a57_pd > /cpus/cpu@0 800 /740 1320 /1720 ,0 (cached stop) > /cpus/cpu@1 800 /740 1420 /1780 ,0 (cached stop) > /D1 660 /580 16560 /6080 ,2199420 (cached stop) > > >Device power-states >------------------- > >some devices, like L2 caches, may feature a shallower retention mode, between CPU_SLEEP_0 >and CLUSTER_SLEEP_0, in which mode the L2 memory is not powered off, leading to faster >resume than CLUSTER_SLEEP_0. > >One way to handle device constrains and retention features in the power-domain, is to >allow devices to register a new power-state (consistent with a c-state). > >idle-states: > > D1_RETENTION: d1-retention { > compatible = "arm,power-state"; > /*leave the psci param, for demo/testing: > * the psci cpuidle driver will not currently > * understand that a c-state shall not have it's > * table entry with a firmware command. > * the actual .power_on/off would be registered > * by the DECLARE macro for a given domain*/ > arm,psci-suspend-param = <0x1010000>; > local-timer-stop; > entry-latency-us = <800>; > exit-latency-us = <200>; > min-residency-us = <2500>; > }; > > > D1 { > compatible = "fake,fake-driver"; > name = "D1"; > constraint = <30000>; > power-domains = <&a53_pd>; > power-states =<&D1_RETENTION>; > }; > > >The genpd simple governor can now upon suspend of the last-man CPU chose a shallower >retention state than CLUSTER_SLEEP_0. > >In order to achieve this, this patch set added the power-state parsing during the >genpd_dev_pm_attach call. Multiple genpd states are now inserted in a sorted manner >according to their depth: see pm_genpd_insert_state in "drivers/base/power/domain.c". > > > >2) DEPENDENCIES > > This patch set applies over linux-4.2rc5 plus the following ordered dependencies: > > * Ulf Hansson: > >6637131 New [V4] PM / Domains: Remove intermediate states from the power off sequence > > * Lina Iyer's patch series: > >7118981 Not Applicable [v2,1/7] PM / Domains: Allocate memory outside domain locks >7118991 Not Applicable [v2,2/7] PM / Domains: Support IRQ safe PM domains >7119001 Not Applicable [v2,3/7] drivers: cpu: Define CPU devices as IRQ safe >7119011 Not Applicable [v2,4/7] PM / Domains: Introduce PM domains for CPUs/clusters >7119021 Not Applicable [v2,5/7] ARM: cpuidle: Add runtime PM support for CPU idle >7119031 Not Applicable [v2,6/7] ARM64: smp: Add runtime PM support for CPU hotplug >7119041 Not Applicable [v2,7/7] ARM: smp: Add runtime PM support for CPU hotplug > > * John Medhurst: > >6303671 New arm64: dts: Add idle-states for Juno > > * Axel Haslam: > >6301741 Not Applicable [v7,1/5] PM / Domains: prepare for multiple states >6301751 Not Applicable [v7,2/5] PM / Domains: core changes for multiple states >6301781 Not Applicable [v7,3/5] PM / Domains: make governor select deepest state >6301771 Not Applicable [v7,4/5] ARM: imx6: pm: declare pm domain latency on power_state struct. >6301761 Not Applicable [v7,5/5] PM / Domains: remove old power on/off latencies. > >2) URL > >playable from https://github.com/mtitinger/linux-pm.git > >by adding the "fake driver D1" and launching the test-dev-state.sh script. >this will show the power domain suspending to an intermediate state, based on the >device constraints. > > domain status pstate slaves > /device runtime status >----------------------------------------------------------------------------------- >a53_pd on > /devices/system/cpu/cpu0 active > /devices/system/cpu/cpu3 suspended > /devices/system/cpu/cpu4 suspended > /devices/system/cpu/cpu5 suspended >a57_pd d1-retention > /devices/system/cpu/cpu1 suspended > /devices/system/cpu/cpu2 suspended > /devices/platform/D1 > >---------------------------------------------------------------------- > >Marc Titinger (6): > arm64: Juno: declare generic power domains for both clusters. > PM / Domains: prepare for devices that might register a power state > PM / Domains: introduce power-states consistent with c-states. > PM / Domains: succeed & warn when attaching non-irqsafe devices to an > irq-safe domain. > arm: cpuidle: let genpd handle the cluster power transition with > 'power-states' > PM / Domains: add debugfs 'states' and 'timings' seq files > > .../devicetree/bindings/arm/idle-states.txt | 21 +- > .../devicetree/bindings/power/power_domain.txt | 29 ++ > arch/arm64/boot/dts/arm/juno.dts | 25 +- > drivers/base/power/cpu-pd.c | 5 + > drivers/base/power/domain.c | 415 +++++++++++++++------ > drivers/cpuidle/cpuidle-arm.c | 52 ++- > include/linux/pm_domain.h | 21 +- > 7 files changed, 437 insertions(+), 131 deletions(-) > >-- >1.9.1 >
| |