diff options
| -rw-r--r-- | src/cpu/minor/cpu.cc | 46 | ||||
| -rw-r--r-- | src/cpu/minor/cpu.hh | 10 | ||||
| -rw-r--r-- | src/cpu/minor/execute.cc | 3 | ||||
| -rw-r--r-- | src/cpu/minor/fetch2.cc | 1 | ||||
| -rw-r--r-- | src/cpu/minor/fetch2.hh | 9 | ||||
| -rw-r--r-- | src/cpu/minor/pipeline.cc | 1 |
6 files changed, 54 insertions, 16 deletions
diff --git a/src/cpu/minor/cpu.cc b/src/cpu/minor/cpu.cc index 63efde2dc..484457bd4 100644 --- a/src/cpu/minor/cpu.cc +++ b/src/cpu/minor/cpu.cc @@ -49,6 +49,7 @@ MinorCPU::MinorCPU(MinorCPUParams *params) : BaseCPU(params), + pipelineStartupEvent([this]{ wakeupPipeline(); }, name()), threadPolicy(params->threadPolicy) { /* This is only written for one thread at the moment */ @@ -279,20 +280,43 @@ MinorCPU::takeOverFrom(BaseCPU *old_cpu) void MinorCPU::activateContext(ThreadID thread_id) { - DPRINTF(MinorCPU, "ActivateContext thread: %d\n", thread_id); + /* Remember to wake up this thread_id by scheduling the + * pipelineStartup event. + * We can't wakeupFetch the thread right away because its context may + * not have been fully initialized. For example, in the case of clone + * syscall, this activateContext function is called in the middle of + * the syscall and before the new thread context is initialized. + * If we start fetching right away, the new thread will fetch from an + * invalid address (i.e., pc is not initialized yet), which could lead + * to a page fault. Instead, we remember which threads to wake up and + * schedule an event to wake all them up after their contexts are + * fully initialized */ + readyThreads.push_back(thread_id); + if (!pipelineStartupEvent.scheduled()) + schedule(pipelineStartupEvent, clockEdge(Cycles(0))); +} - /* Do some cycle accounting. lastStopped is reset to stop the - * wakeup call on the pipeline from adding the quiesce period - * to BaseCPU::numCycles */ - stats.quiesceCycles += pipeline->cyclesSinceLastStopped(); - pipeline->resetLastStopped(); +void +MinorCPU::wakeupPipeline() +{ + for (auto thread_id : readyThreads) { + DPRINTF(MinorCPU, "ActivateContext thread: %d\n", thread_id); - /* Wake up the thread, wakeup the pipeline tick */ - threads[thread_id]->activate(); - wakeupOnEvent(Minor::Pipeline::CPUStageId); - pipeline->wakeupFetch(thread_id); + /* Do some cycle accounting. lastStopped is reset to stop the + * wakeup call on the pipeline from adding the quiesce period + * to BaseCPU::numCycles */ + stats.quiesceCycles += pipeline->cyclesSinceLastStopped(); + pipeline->resetLastStopped(); + + /* Wake up the thread, wakeup the pipeline tick */ + threads[thread_id]->activate(); + wakeupOnEvent(Minor::Pipeline::CPUStageId); + + pipeline->wakeupFetch(thread_id); + BaseCPU::activateContext(thread_id); + } - BaseCPU::activateContext(thread_id); + readyThreads.clear(); } void diff --git a/src/cpu/minor/cpu.hh b/src/cpu/minor/cpu.hh index 4e4762390..606a401b6 100644 --- a/src/cpu/minor/cpu.hh +++ b/src/cpu/minor/cpu.hh @@ -83,6 +83,13 @@ class MinorCPU : public BaseCPU * Elements of pipeline call TheISA to implement the model. */ Minor::Pipeline *pipeline; + /** An event that wakes up the pipeline when a thread context is + * activated */ + EventFunctionWrapper pipelineStartupEvent; + + /** List of threads that are ready to wake up and run */ + std::vector<ThreadID> readyThreads; + public: /** Activity recording for pipeline. This belongs to Pipeline but * stages will access it through the CPU as the MinorCPU object @@ -165,6 +172,9 @@ class MinorCPU : public BaseCPU void activateContext(ThreadID thread_id) override; void suspendContext(ThreadID thread_id) override; + /** Wake up ready-to-run threads */ + void wakeupPipeline(); + /** Thread scheduling utility functions */ std::vector<ThreadID> roundRobinPriority(ThreadID priority) { diff --git a/src/cpu/minor/execute.cc b/src/cpu/minor/execute.cc index 7b76ca2e1..93c0895ac 100644 --- a/src/cpu/minor/execute.cc +++ b/src/cpu/minor/execute.cc @@ -1054,7 +1054,8 @@ Execute::commit(ThreadID thread_id, bool only_commit_microops, bool discard, !branch.isStreamChange() && /* No real branch */ fault == NoFault && /* No faults */ completed_inst && /* Still finding instructions to execute */ - num_insts_committed != commitLimit /* Not reached commit limit */ + num_insts_committed != commitLimit && /* Not reached commit limit */ + cpu.getContext(thread_id)->status() != ThreadContext::Suspended ) { if (only_commit_microops) { diff --git a/src/cpu/minor/fetch2.cc b/src/cpu/minor/fetch2.cc index ba898d987..09a06fc24 100644 --- a/src/cpu/minor/fetch2.cc +++ b/src/cpu/minor/fetch2.cc @@ -120,6 +120,7 @@ Fetch2::dumpAllInput(ThreadID tid) popInput(tid); fetchInfo[tid].inputIndex = 0; + fetchInfo[tid].havePC = false; } void diff --git a/src/cpu/minor/fetch2.hh b/src/cpu/minor/fetch2.hh index c66fbd8dc..2230560f1 100644 --- a/src/cpu/minor/fetch2.hh +++ b/src/cpu/minor/fetch2.hh @@ -172,6 +172,11 @@ class Fetch2 : public Named Stats::Scalar loadInstructions; Stats::Scalar storeInstructions; + public: + /** Dump the whole contents of the input buffer. Useful after a + * prediction changes control flow */ + void dumpAllInput(ThreadID tid); + protected: /** Get a piece of data to work on from the inputBuffer, or 0 if there * is no data. */ @@ -180,10 +185,6 @@ class Fetch2 : public Named /** Pop an element off the input buffer, if there are any */ void popInput(ThreadID tid); - /** Dump the whole contents of the input buffer. Useful after a - * prediction changes control flow */ - void dumpAllInput(ThreadID tid); - /** Update local branch prediction structures from feedback from * Execute. */ void updateBranchPrediction(const BranchData &branch); diff --git a/src/cpu/minor/pipeline.cc b/src/cpu/minor/pipeline.cc index b5659ac0d..3248d5465 100644 --- a/src/cpu/minor/pipeline.cc +++ b/src/cpu/minor/pipeline.cc @@ -199,6 +199,7 @@ void Pipeline::wakeupFetch(ThreadID tid) { fetch1.wakeupFetch(tid); + fetch2.dumpAllInput(tid); } bool |