From 818961969a9a74f8b0106e6cbe442e02fc2a6d9b Mon Sep 17 00:00:00 2001 From: Anouk Van Laer Date: Wed, 4 Oct 2017 14:14:33 +0100 Subject: [PATCH] sim-power: Creation of PowerState class This commit does not make any functional changes but just rearranges the existing code with regard to the power states. Previously, all code regarding power states was in the ClockedObjects. However, it seems more logical and cleaner to move this code into a separate class, called PowerState. The PowerState is a now SimObject. Every ClockedObject has a PowerState but this patch also allows for objects with PowerState which are not ClockedObjects. Change-Id: Id2db86dc14f140dc9d0912a8a7de237b9df9120d Reviewed-by: Andreas Sandberg Reviewed-by: Sascha Bischoff Signed-off-by: Nikos Nikoleris Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/28049 Reviewed-by: Bobby R. Bruce Maintainer: Jason Lowe-Power Tested-by: kokoro --- configs/example/arm/fs_power.py | 4 +- src/cpu/base.cc | 18 +-- src/dev/arm/fvp_base_pwr_ctrl.cc | 4 +- src/sim/ClockedObject.py | 29 +---- src/sim/PowerState.py | 67 +++++++++++ src/sim/SConscript | 2 + src/sim/clocked_object.cc | 154 ++---------------------- src/sim/clocked_object.hh | 48 +------- src/sim/power/power_model.cc | 4 +- src/sim/power_state.cc | 200 +++++++++++++++++++++++++++++++ src/sim/power_state.hh | 133 ++++++++++++++++++++ 11 files changed, 432 insertions(+), 231 deletions(-) create mode 100644 src/sim/PowerState.py create mode 100644 src/sim/power_state.cc create mode 100644 src/sim/power_state.hh diff --git a/configs/example/arm/fs_power.py b/configs/example/arm/fs_power.py index abc759e22..72c62920c 100644 --- a/configs/example/arm/fs_power.py +++ b/configs/example/arm/fs_power.py @@ -114,7 +114,7 @@ def main(): if not isinstance(cpu, m5.objects.BaseCPU): continue - cpu.default_p_state = "ON" + cpu.power_state.default_state = "ON" cpu.power_model = CpuPowerModel(cpu.path()) # Example power model for the L2 Cache of the bigCluster @@ -122,7 +122,7 @@ def main(): if not isinstance(l2, m5.objects.Cache): continue - l2.default_p_state = "ON" + l2.power_state.default_state = "ON" l2.power_model = L2PowerModel(l2.path()) bL.instantiate(options) diff --git a/src/cpu/base.cc b/src/cpu/base.cc index d9cbc1c35..36474829f 100644 --- a/src/cpu/base.cc +++ b/src/cpu/base.cc @@ -329,11 +329,11 @@ BaseCPU::startup() } if (_switchedOut) - ClockedObject::pwrState(Enums::PwrState::OFF); + powerState->set(Enums::PwrState::OFF); // Assumption CPU start to operate instantaneously without any latency - if (ClockedObject::pwrState() == Enums::PwrState::UNDEFINED) - ClockedObject::pwrState(Enums::PwrState::ON); + if (powerState->get() == Enums::PwrState::UNDEFINED) + powerState->set(Enums::PwrState::ON); } @@ -463,7 +463,7 @@ BaseCPU::schedulePowerGatingEvent() return; } - if (ClockedObject::pwrState() == Enums::PwrState::CLK_GATED && + if (powerState->get() == Enums::PwrState::CLK_GATED && powerGatingOnIdle) { assert(!enterPwrGatingEvent.scheduled()); // Schedule a power gating event when clock gated for the specified @@ -492,7 +492,7 @@ BaseCPU::activateContext(ThreadID thread_num) if (enterPwrGatingEvent.scheduled()) deschedule(enterPwrGatingEvent); // For any active thread running, update CPU power state to active (ON) - ClockedObject::pwrState(Enums::PwrState::ON); + powerState->set(Enums::PwrState::ON); updateCycleCounters(CPU_STATE_WAKEUP); } @@ -513,7 +513,7 @@ BaseCPU::suspendContext(ThreadID thread_num) updateCycleCounters(CPU_STATE_SLEEP); // All CPU threads suspended, enter lower power state for the CPU - ClockedObject::pwrState(Enums::PwrState::CLK_GATED); + powerState->set(Enums::PwrState::CLK_GATED); // If pwrGatingLatency is set to 0 then this mechanism is disabled if (powerGatingOnIdle) { @@ -532,7 +532,7 @@ BaseCPU::haltContext(ThreadID thread_num) void BaseCPU::enterPwrGating(void) { - ClockedObject::pwrState(Enums::PwrState::OFF); + powerState->set(Enums::PwrState::OFF); } void @@ -548,7 +548,7 @@ BaseCPU::switchOut() flushTLBs(); // Go to the power gating state - ClockedObject::pwrState(Enums::PwrState::OFF); + powerState->set(Enums::PwrState::OFF); } void @@ -561,7 +561,7 @@ BaseCPU::takeOverFrom(BaseCPU *oldCPU) _pid = oldCPU->getPid(); _taskId = oldCPU->taskId(); // Take over the power state of the switchedOut CPU - ClockedObject::pwrState(oldCPU->pwrState()); + powerState->set(oldCPU->powerState->get()); previousState = oldCPU->previousState; previousCycle = oldCPU->previousCycle; diff --git a/src/dev/arm/fvp_base_pwr_ctrl.cc b/src/dev/arm/fvp_base_pwr_ctrl.cc index a6650b893..5113c926e 100644 --- a/src/dev/arm/fvp_base_pwr_ctrl.cc +++ b/src/dev/arm/fvp_base_pwr_ctrl.cc @@ -280,7 +280,7 @@ FVPBasePwrCtrl::powerCoreOn(ThreadContext *const tc, PwrStatus *const pwrs) npwrs->pc = 0; } } - tc->getCpuPtr()->pwrState(Enums::PwrState::ON); + tc->getCpuPtr()->powerState->set(Enums::PwrState::ON); } void @@ -295,7 +295,7 @@ FVPBasePwrCtrl::powerCoreOff(ThreadContext *const tc, PwrStatus *const pwrs) pwrs->pc = 0; // Clear power-on reason pwrs->wk = 0; - tc->getCpuPtr()->pwrState(Enums::PwrState::OFF); + tc->getCpuPtr()->powerState->set(Enums::PwrState::OFF); } void diff --git a/src/sim/ClockedObject.py b/src/sim/ClockedObject.py index 3819093b6..873261372 100644 --- a/src/sim/ClockedObject.py +++ b/src/sim/ClockedObject.py @@ -1,4 +1,4 @@ -# Copyright (c) 2012, 2015-2016 ARM Limited +# Copyright (c) 2012, 2015-2017, 2019-2020 ARM Limited # All rights reserved. # # The license below extends only to copyright in the software and shall @@ -33,28 +33,11 @@ # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. +from m5.objects.PowerState import PowerState from m5.SimObject import SimObject from m5.params import * from m5.proxy import * -# Enumerate set of allowed power states that can be used by a clocked object. -# The list is kept generic to express a base minimal set. -# State definition :- -# Undefined: Invalid state, no power state derived information is available. -# On: The logic block is actively running and consuming dynamic and leakage -# energy depending on the amount of processing required. -# Clk_gated: The clock circuity within the block is gated to save dynamic -# energy, the power supply to the block is still on and leakage -# energy is being consumed by the block. -# Sram_retention: The SRAMs within the logic blocks are pulled into retention -# state to reduce leakage energy further. -# Off: The logic block is power gated and is not consuming any energy. -class PwrState(Enum): vals = ['UNDEFINED', - 'ON', - 'CLK_GATED', - 'SRAM_RETENTION', - 'OFF'] - class ClockedObject(SimObject): type = 'ClockedObject' abstract = True @@ -67,11 +50,5 @@ class ClockedObject(SimObject): # Power model for this ClockedObject power_model = VectorParam.PowerModel([], "Power models") - # Provide initial power state, should ideally get redefined in startup - # routine - default_p_state = Param.PwrState("UNDEFINED", "Default Power State") + power_state = Param.PowerState(PowerState(), "Power state") - p_state_clk_gate_min = Param.Latency('1ns',"Min value of the distribution") - p_state_clk_gate_max = Param.Latency('1s',"Max value of the distribution") - p_state_clk_gate_bins = Param.Unsigned('20', - "# bins in clk gated distribution") diff --git a/src/sim/PowerState.py b/src/sim/PowerState.py new file mode 100644 index 000000000..59491ec15 --- /dev/null +++ b/src/sim/PowerState.py @@ -0,0 +1,67 @@ +# Copyright (c) 2012, 2015-2017 ARM Limited +# All rights reserved. +# +# The license below extends only to copyright in the software and shall +# not be construed as granting a license to any other intellectual +# property including but not limited to intellectual property relating +# to a hardware implementation of the functionality of the software +# licensed hereunder. You may use the software subject to the license +# terms below provided that you ensure that this notice is replicated +# unmodified and in its entirety in all distributions of the software, +# modified or unmodified, in source code or in binary form. +# +# Redistribution and use in source and binary forms, with or without +# modification, are permitted provided that the following conditions are +# met: redistributions of source code must retain the above copyright +# notice, this list of conditions and the following disclaimer; +# redistributions in binary form must reproduce the above copyright +# notice, this list of conditions and the following disclaimer in the +# documentation and/or other materials provided with the distribution; +# neither the name of the copyright holders nor the names of its +# contributors may be used to endorse or promote products derived from +# this software without specific prior written permission. +# +# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. +# + +from m5.SimObject import SimObject +from m5.params import * +from m5.proxy import * + +# Enumerate set of allowed power states that can be used by a clocked object. +# The list is kept generic to express a base minimal set. +# State definition :- +# Undefined: Invalid state, no power state derived information is available. +# On: The logic block is actively running and consuming dynamic and leakage +# energy depending on the amount of processing required. +# Clk_gated: The clock circuity within the block is gated to save dynamic +# energy, the power supply to the block is still on and leakage +# energy is being consumed by the block. +# Sram_retention: The SRAMs within the logic blocks are pulled into retention +# state to reduce leakage energy further. +# Off: The logic block is power gated and is not consuming any energy. +class PwrState(Enum): vals = [ + 'UNDEFINED', 'ON', 'CLK_GATED', 'SRAM_RETENTION', 'OFF' +] + +class PowerState(SimObject): + type = 'PowerState' + cxx_header = "sim/power_state.hh" + + # Provide initial power state, should ideally get redefined in startup + # routine + default_state = Param.PwrState("UNDEFINED", "Default Power State") + + clk_gate_min = Param.Latency('1ns',"Min value of the distribution") + clk_gate_max = Param.Latency('1s',"Max value of the distribution") + clk_gate_bins = Param.Unsigned('20', "# bins in clk gated distribution") diff --git a/src/sim/SConscript b/src/sim/SConscript index 703b8e1d3..274faf9c1 100644 --- a/src/sim/SConscript +++ b/src/sim/SConscript @@ -38,6 +38,7 @@ SimObject('System.py') SimObject('DVFSHandler.py') SimObject('SubSystem.py') SimObject('RedirectPath.py') +SimObject('PowerState.py') Source('async.cc') Source('backtrace_%s.cc' % env['BACKTRACE_IMPL']) @@ -75,6 +76,7 @@ Source('system.cc') Source('dvfs_handler.cc') Source('clocked_object.cc') Source('mathexpr.cc') +Source('power_state.cc') GTest('byteswap.test', 'byteswap.test.cc', '../base/types.cc') GTest('guest_abi.test', 'guest_abi.test.cc') diff --git a/src/sim/clocked_object.cc b/src/sim/clocked_object.cc index f66b77639..e7aaca7db 100644 --- a/src/sim/clocked_object.cc +++ b/src/sim/clocked_object.cc @@ -1,5 +1,5 @@ /* - * Copyright (c) 2015-2016 ARM Limited + * Copyright (c) 2015-2017, 2019-2020 ARM Limited * All rights reserved * * The license below extends only to copyright in the software and shall @@ -41,12 +41,13 @@ #include "sim/power/power_model.hh" ClockedObject::ClockedObject(const ClockedObjectParams *p) : - SimObject(p), Clocked(*p->clk_domain), - _currPwrState(p->default_p_state), - prvEvalTick(0), - stats(*this) + SimObject(p), Clocked(*p->clk_domain), powerState(p->power_state) { // Register the power_model with the object + // Slightly counter-intuitively, power models need to to register with the + // clocked object and not the power stated object because the power model + // needs information from the clock domain, which is an attribute of the + // clocked object. for (auto & power_model: p->power_model) power_model->setClockedObject(this); } @@ -54,149 +55,10 @@ ClockedObject::ClockedObject(const ClockedObjectParams *p) : void ClockedObject::serialize(CheckpointOut &cp) const { - unsigned int currPwrState = (unsigned int)_currPwrState; - - SERIALIZE_SCALAR(currPwrState); - SERIALIZE_SCALAR(prvEvalTick); + powerState->serialize(cp); } - void ClockedObject::unserialize(CheckpointIn &cp) { - unsigned int currPwrState; - - UNSERIALIZE_SCALAR(currPwrState); - UNSERIALIZE_SCALAR(prvEvalTick); - - _currPwrState = Enums::PwrState(currPwrState); -} - -void -ClockedObject::pwrState(Enums::PwrState p) -{ - // Function should ideally be called only when there is a state change - if (_currPwrState == p) { - warn_once("ClockedObject: Already in the requested power state, " \ - "request ignored"); - return; - } - - // No need to compute stats if in the same tick, update state though. This - // can happen in cases like a) during start of the simulation multiple - // state changes happens in init/startup phase, b) one takes a decision to - // migrate state but decides to reverts back to the original state in the - // same tick if other conditions are not met elsewhere. - // Any state change related stats would have been recorded on previous call - // to the pwrState() function. - if (prvEvalTick == curTick() && curTick() != 0) { - warn("ClockedObject %s: More than one power state change request "\ - "encountered within the same simulation tick %d", - name(), prvEvalTick); - _currPwrState = p; - return; - } - - // Record stats for previous state. - computeStats(); - - _currPwrState = p; - - stats.numPwrStateTransitions++; -} - -void -ClockedObject::computeStats() -{ - // Calculate time elapsed from last (valid) state change - Tick elapsed_time = curTick() - prvEvalTick; - - stats.pwrStateResidencyTicks[_currPwrState] += elapsed_time; - - // Time spent in CLK_GATED state, this might change depending on - // transition to other low power states in respective simulation - // objects. - if (_currPwrState == Enums::PwrState::CLK_GATED) { - stats.pwrStateClkGateDist.sample(elapsed_time); - } - - prvEvalTick = curTick(); -} - -std::vector -ClockedObject::pwrStateWeights() const -{ - // Get residency stats - std::vector ret; - Stats::VCounter residencies; - stats.pwrStateResidencyTicks.value(residencies); - - // Account for current state too! - Tick elapsed_time = curTick() - prvEvalTick; - residencies[_currPwrState] += elapsed_time; - - ret.resize(Enums::PwrState::Num_PwrState); - for (unsigned i = 0; i < Enums::PwrState::Num_PwrState; i++) - ret[i] = residencies[i] / \ - (stats.pwrStateResidencyTicks.total() + elapsed_time); - - return ret; -} - - -ClockedObject::ClockedObjectStats::ClockedObjectStats(ClockedObject &co) - : Stats::Group(&co), - clockedObject(co), - ADD_STAT(numPwrStateTransitions, - "Number of power state transitions"), - ADD_STAT(pwrStateClkGateDist, - "Distribution of time spent in the clock gated state"), - ADD_STAT(pwrStateResidencyTicks, - "Cumulative time (in ticks) in various power states") -{ -} - -void -ClockedObject::ClockedObjectStats::regStats() -{ - Stats::Group::regStats(); - - using namespace Stats; - - const ClockedObjectParams *p = clockedObject.params(); - - numPwrStateTransitions.flags(nozero); - - // Each sample is time in ticks - unsigned num_bins = std::max(p->p_state_clk_gate_bins, 10U); - pwrStateClkGateDist - .init(p->p_state_clk_gate_min, p->p_state_clk_gate_max, - (p->p_state_clk_gate_max / num_bins)) - .flags(pdf | nozero | nonan) - ; - - pwrStateResidencyTicks - .init(Enums::PwrState::Num_PwrState) - .flags(nozero) - ; - for (int i = 0; i < Enums::PwrState::Num_PwrState; i++) { - pwrStateResidencyTicks.subname(i, Enums::PwrStateStrings[i]); - } - - numPwrStateTransitions = 0; -} - -void -ClockedObject::ClockedObjectStats::preDumpStats() -{ - Stats::Group::preDumpStats(); - - /** - * For every stats dump, the power state residency and other distribution - * stats should be computed just before the dump to ensure correct stats - * value being reported for current dump window. It avoids things like - * having any unreported time spent in a power state to be forwarded to the - * next dump window which might have rather unpleasant effects (like - * perturbing the distribution stats). - */ - clockedObject.computeStats(); + powerState->unserialize(cp); } diff --git a/src/sim/clocked_object.hh b/src/sim/clocked_object.hh index 10a7fedc7..4f94df80b 100644 --- a/src/sim/clocked_object.hh +++ b/src/sim/clocked_object.hh @@ -1,5 +1,5 @@ /* - * Copyright (c) 2012-2013, 2015-2016 ARM Limited + * Copyright (c) 2012-2013, 2015-2017, 2019-2020 ARM Limited * Copyright (c) 2013 Cornell University * All rights reserved * @@ -44,12 +44,11 @@ #ifndef __SIM_CLOCKED_OBJECT_HH__ #define __SIM_CLOCKED_OBJECT_HH__ -#include "base/callback.hh" -#include "base/intmath.hh" -#include "enums/PwrState.hh" + #include "params/ClockedObject.hh" #include "sim/core.hh" #include "sim/clock_domain.hh" +#include "sim/power_state.hh" #include "sim/sim_object.hh" /** @@ -245,46 +244,7 @@ class ClockedObject : public SimObject, public Clocked void serialize(CheckpointOut &cp) const override; void unserialize(CheckpointIn &cp) override; - Enums::PwrState pwrState() const { return _currPwrState; } - - std::string - pwrStateName() const - { - return Enums::PwrStateStrings[_currPwrState]; - } - - /** Returns the percentage residency for each power state */ - std::vector pwrStateWeights() const; - - /** - * Record stats values like state residency by computing the time - * difference from previous update. Also, updates the previous evaluation - * tick once all stats are recorded. - * Usually called on power state change and stats dump callback. - */ - void computeStats(); - - void pwrState(Enums::PwrState); - - protected: - - /** To keep track of the current power state */ - Enums::PwrState _currPwrState; - - Tick prvEvalTick; - - struct ClockedObjectStats : public Stats::Group - { - ClockedObjectStats(ClockedObject &co); - - void regStats() override; - void preDumpStats() override; - - ClockedObject &clockedObject; - Stats::Scalar numPwrStateTransitions; - Stats::Distribution pwrStateClkGateDist; - Stats::Vector pwrStateResidencyTicks; - } stats; + PowerState *powerState; }; #endif //__SIM_CLOCKED_OBJECT_HH__ diff --git a/src/sim/power/power_model.cc b/src/sim/power/power_model.cc index 43eb436b2..ec1b62d1e 100644 --- a/src/sim/power/power_model.cc +++ b/src/sim/power/power_model.cc @@ -102,7 +102,7 @@ PowerModel::getDynamicPower() const // This power model only collects static data return 0; } - std::vector w = clocked_object->pwrStateWeights(); + std::vector w = clocked_object->powerState->getWeights(); // Same number of states (excluding UNDEFINED) assert(w.size() - 1 == states_pm.size()); @@ -124,7 +124,7 @@ PowerModel::getStaticPower() const { assert(clocked_object); - std::vector w = clocked_object->pwrStateWeights(); + std::vector w = clocked_object->powerState->getWeights(); if (power_model_type == Enums::PMType::Dynamic) { // This power model only collects dynamic data diff --git a/src/sim/power_state.cc b/src/sim/power_state.cc new file mode 100644 index 000000000..28b0b83de --- /dev/null +++ b/src/sim/power_state.cc @@ -0,0 +1,200 @@ +/* + * Copyright (c) 2015-2017, 2019-2020 ARM Limited + * All rights reserved + * + * The license below extends only to copyright in the software and shall + * not be construed as granting a license to any other intellectual + * property including but not limited to intellectual property relating + * to a hardware implementation of the functionality of the software + * licensed hereunder. You may use the software subject to the license + * terms below provided that you ensure that this notice is replicated + * unmodified and in its entirety in all distributions of the software, + * modified or unmodified, in source code or in binary form. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer; + * redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution; + * neither the name of the copyright holders nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#include "sim/power_state.hh" + +#include "base/logging.hh" + +PowerState::PowerState(const PowerStateParams *p) : + SimObject(p), _currState(p->default_state), + stats(*this) +{ +} + +void +PowerState::serialize(CheckpointOut &cp) const +{ + unsigned int currState = (unsigned int)_currState; + + SERIALIZE_SCALAR(currState); + SERIALIZE_SCALAR(prvEvalTick); +} + +void +PowerState::unserialize(CheckpointIn &cp) +{ + unsigned int currState; + + UNSERIALIZE_SCALAR(currState); + UNSERIALIZE_SCALAR(prvEvalTick); + + _currState = Enums::PwrState(currState); +} + +void +PowerState::set(Enums::PwrState p) +{ + // Function should ideally be called only when there is a state change + if (_currState == p) { + warn_once("PowerState: Already in the requested power state, " + "request ignored"); + return; + } + + // No need to compute stats if in the same tick, update state though. This + // can happen in cases like a) during start of the simulation multiple + // state changes happens in init/startup phase, b) one takes a decision to + // migrate state but decides to reverts back to the original state in the + // same tick if other conditions are not met elsewhere. + // Any state change related stats would have been recorded on previous call + // to this function. + if (prvEvalTick == curTick() && curTick() != 0) { + warn("PowerState: More than one power state change request " + "encountered within the same simulation tick"); + _currState = p; + return; + } + + // Record stats for previous state. + computeStats(); + + _currState = p; + + stats.numTransitions++; +} + +void +PowerState::computeStats() +{ + // Calculate time elapsed from last (valid) state change + Tick elapsed_time = curTick() - prvEvalTick; + + stats.pwrStateResidencyTicks[_currState] += elapsed_time; + + // Time spent in CLK_GATED state, this might change depending on + // transition to other low power states in respective simulation + // objects. + if (_currState == Enums::PwrState::CLK_GATED) { + stats.ticksClkGated.sample(elapsed_time); + } + + prvEvalTick = curTick(); +} + +std::vector +PowerState::getWeights() const +{ + // Get residency stats + std::vector ret; + Stats::VCounter residencies; + stats.pwrStateResidencyTicks.value(residencies); + + // Account for current state too! + Tick elapsed_time = curTick() - prvEvalTick; + residencies[_currState] += elapsed_time; + + ret.resize(Enums::PwrState::Num_PwrState); + for (unsigned i = 0; i < Enums::PwrState::Num_PwrState; i++) + ret[i] = residencies[i] / \ + (stats.pwrStateResidencyTicks.total() + elapsed_time); + + return ret; +} + +PowerState::PowerStateStats::PowerStateStats(PowerState &co) + : Stats::Group(&co), + powerState(co), + ADD_STAT(numTransitions, + "Number of power state transitions"), + ADD_STAT(ticksClkGated, + "Distribution of time spent in the clock gated state"), + ADD_STAT(pwrStateResidencyTicks, + "Cumulative time (in ticks) in various power states") +{ +} + +void +PowerState::PowerStateStats::regStats() +{ + Stats::Group::regStats(); + + using namespace Stats; + + const PowerStateParams *p = powerState.params(); + + numTransitions.flags(nozero); + + // Each sample is time in ticks + unsigned num_bins = std::max(p->clk_gate_bins, 10U); + ticksClkGated + .init(p->clk_gate_min, p->clk_gate_max, + (p->clk_gate_max / num_bins)) + .flags(pdf | nozero | nonan) + ; + + pwrStateResidencyTicks + .init(Enums::PwrState::Num_PwrState) + .flags(nozero) + ; + for (int i = 0; i < Enums::PwrState::Num_PwrState; i++) { + pwrStateResidencyTicks.subname(i, Enums::PwrStateStrings[i]); + } + + numTransitions = 0; +} + +void +PowerState::PowerStateStats::preDumpStats() +{ + Stats::Group::preDumpStats(); + + /** + * For every stats dump, the power state residency and other distribution + * stats should be computed just before the dump to ensure correct stats + * value being reported for current dump window. It avoids things like + * having any unreported time spent in a power state to be forwarded to the + * next dump window which might have rather unpleasant effects (like + * perturbing the distribution stats). + */ + powerState.computeStats(); +} + +PowerState* +PowerStateParams::create() +{ + return new PowerState(this); +} diff --git a/src/sim/power_state.hh b/src/sim/power_state.hh new file mode 100644 index 000000000..8b93b450b --- /dev/null +++ b/src/sim/power_state.hh @@ -0,0 +1,133 @@ +/* + * Copyright (c) 2015-2017, 2020 ARM Limited + * All rights reserved + * + * The license below extends only to copyright in the software and shall + * not be construed as granting a license to any other intellectual + * property including but not limited to intellectual property relating + * to a hardware implementation of the functionality of the software + * licensed hereunder. You may use the software subject to the license + * terms below provided that you ensure that this notice is replicated + * unmodified and in its entirety in all distributions of the software, + * modified or unmodified, in source code or in binary form. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer; + * redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution; + * neither the name of the copyright holders nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +/** + * @file + * PowerState declaration and implementation. + */ + +#ifndef __SIM_POWER_STATE_HH__ +#define __SIM_POWER_STATE_HH__ + +#include + +#include "base/callback.hh" +#include "base/statistics.hh" +#include "enums/PwrState.hh" +#include "params/PowerState.hh" +#include "sim/core.hh" +#include "sim/sim_object.hh" + +/** + * Helper class for objects that have power states. This class provides the + * basic functionality to change between power states. + */ +class PowerState : public SimObject +{ + public: + PowerState(const PowerStateParams *p); + + /** Parameters of PowerState object */ + typedef PowerStateParams Params; + const Params* params() const + { + return reinterpret_cast(_params); + } + + void serialize(CheckpointOut &cp) const override; + void unserialize(CheckpointIn &cp) override; + + /** + * Change the power state of this object to the power state p + */ + void set(Enums::PwrState p); + + + inline Enums::PwrState get() const + { + return _currState; + } + + inline std::string getName() const + { + return Enums::PwrStateStrings[_currState]; + } + + /** Returns the percentage residency for each power state */ + std::vector getWeights() const; + + /** + * Record stats values like state residency by computing the time + * difference from previous update. Also, updates the previous evaluation + * tick once all stats are recorded. + * Usually called on power state change and stats dump callback. + */ + void computeStats(); + + protected: + + /** To keep track of the current power state */ + Enums::PwrState _currState; + + /** Last tick the power stats were calculated */ + Tick prvEvalTick = 0; + + struct PowerStateStats : public Stats::Group + { + PowerStateStats(PowerState &ps); + + void regStats() override; + void preDumpStats() override; + + PowerState &powerState; + + Stats::Scalar numTransitions; + Stats::Distribution ticksClkGated; + /** Tracks the time spent in each of the power states */ + Stats::Vector pwrStateResidencyTicks; + } stats; +}; + +class PowerStateDumpCallback : public Callback +{ + PowerState *co; + public: + PowerStateDumpCallback(PowerState *co_t) : co(co_t) {} + virtual void process() { co->computeStats(); }; +}; + +#endif //__SIM_POWER_STATE_HH__ -- 2.30.2