From c97a99110b8beafcf557636688e81861157a8c1e Mon Sep 17 00:00:00 2001 From: Andreas Sandberg Date: Tue, 11 Jun 2013 09:24:55 +0200 Subject: kvm: Separate host frequency from simulated CPU frequency We used to use the KVM CPU's clock to specify the host frequency. This was not ideal for several reasons. One of them being that the clock parameter of a CPU determines the frequency of some of the components connected to the CPU. This changeset adds a separate hostFreq parameter that should be used to specify the host frequency until we add code to autodetect it. The hostFactor should still be used to specify the conversion factor between the host performance and that of the simulated system. --- src/cpu/kvm/BaseKvmCPU.py | 2 ++ src/cpu/kvm/base.cc | 8 ++++---- src/cpu/kvm/base.hh | 4 ++++ 3 files changed, 10 insertions(+), 4 deletions(-) diff --git a/src/cpu/kvm/BaseKvmCPU.py b/src/cpu/kvm/BaseKvmCPU.py index 796a7794b..644ca3620 100644 --- a/src/cpu/kvm/BaseKvmCPU.py +++ b/src/cpu/kvm/BaseKvmCPU.py @@ -71,4 +71,6 @@ class BaseKvmCPU(BaseCPU): kvmVM = Param.KvmVM(Parent.any, 'KVM VM (i.e., shared memory domain)') useCoalescedMMIO = Param.Bool(False, "Use coalesced MMIO (EXPERIMENTAL)") usePerfOverflow = Param.Bool(False, "Use perf event overflow counters (EXPERIMENTAL)") + + hostFreq = Param.Clock("2GHz", "Host clock frequency") hostFactor = Param.Float(1.0, "Cycle scale factor") diff --git a/src/cpu/kvm/base.cc b/src/cpu/kvm/base.cc index 3bfe44cf4..539790e52 100644 --- a/src/cpu/kvm/base.cc +++ b/src/cpu/kvm/base.cc @@ -83,6 +83,7 @@ BaseKvmCPU::BaseKvmCPU(BaseKvmCPUParams *params) pageSize(sysconf(_SC_PAGE_SIZE)), tickEvent(*this), perfControlledByTimer(params->usePerfOverflow), + hostFreq(params->hostFreq), hostFactor(params->hostFactor), drainManager(NULL), ctrInsts(0) @@ -103,11 +104,11 @@ BaseKvmCPU::BaseKvmCPU(BaseKvmCPUParams *params) runTimer.reset(new PerfKvmTimer(hwCycles, KVM_TIMER_SIGNAL, params->hostFactor, - params->clock)); + params->hostFreq)); else runTimer.reset(new PosixKvmTimer(KVM_TIMER_SIGNAL, CLOCK_MONOTONIC, params->hostFactor, - params->clock)); + params->hostFreq)); } BaseKvmCPU::~BaseKvmCPU() @@ -410,8 +411,7 @@ BaseKvmCPU::activateContext(ThreadID thread_num, Cycles delay) assert(_status == Idle); assert(!tickEvent.scheduled()); - numCycles += ticksToCycles(thread->lastActivate - thread->lastSuspend) - * hostFactor; + numCycles += ticksToCycles(thread->lastActivate - thread->lastSuspend); schedule(tickEvent, clockEdge(delay)); _status = Running; diff --git a/src/cpu/kvm/base.hh b/src/cpu/kvm/base.hh index 42a7eca2b..2e3ee551b 100644 --- a/src/cpu/kvm/base.hh +++ b/src/cpu/kvm/base.hh @@ -670,6 +670,10 @@ class BaseKvmCPU : public BaseCPU */ std::unique_ptr runTimer; + /** Host frequency */ + Tick hostFreq; + + /** Host factor as specified in the configuration */ float hostFactor; /** -- cgit v1.2.3