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2014-09-03base: Use STL C++11 random number generationAndreas Hansson
This patch changes the random number generator from the in-house Mersenne twister to an implementation relying entirely on C++11 STL. The format for the checkpointing of the twister is simplified. As the functionality was never used this should not matter. Note that this patch does not actually make use of the checkpointing functionality. As the random number generator is not thread safe, it may be sensible to create one generator per thread, system, or even object. Until this is decided the status quo is maintained in that no generator state is part of the checkpoint.
2014-09-03base: Use the global Mersenne twister throughoutAndreas Hansson
This patch tidies up random number generation to ensure that it is done consistently throughout the code base. In essence this involves a clean-up of Ruby, and some code simplifications in the traffic generator. As part of this patch a bunch of skewed distributions (off-by-one etc) have been fixed. Note that a single global random number generator is used, and that the object instantiation order will impact the behaviour (the sequence of numbers will be unaffected, but if module A calles random before module B then they would obviously see a different outcome). The dependency on the instantiation order is true in any case due to the execution-model of gem5, so we leave it as is. Also note that the global ranom generator is not thread safe at this point. Regressions using the memtest, TrafficGen or any Ruby tester are affected and will be updated accordingly.
2014-09-03mem: Avoid unecessary retries when bus peer is not readyAndreas Hansson
This patch removes unecessary retries that happened when the bus layer itself was no longer busy, but the the peer was not yet ready. Instead of sending a retry that will inevitably not succeed, the bus now silenty waits until the peer sends a retry.
2014-09-03arm: Make memory ops work on 64bit/128-bit quantitiesMitch Hayenga
Multiple instructions assume only 32-bit load operations are available, this patch increases load sizes to 64-bit or 128-bit for many load pair and load multiple instructions.
2014-06-27mem: write streaming support via WriteInvalidate promotionCurtis Dunham
Support full-block writes directly rather than requiring RMW: * a cache line is allocated in the cache upon receipt of a WriteInvalidateReq, not the WriteInvalidateResp. * only top-level caches allocate the line; the others just pass the request along and invalidate as necessary. * to close a timing window between the *Req and the *Resp, a new metadata bit tracks whether another cache has read a copy of the new line before the writeback to memory.
2014-09-03mem: Fix a bug in the cache port flow controlAndreas Hansson
This patch fixes a bug in the cache port where the retry flag was reset too early, allowing new requests to arrive before the retry was actually sent, but with the event already scheduled. This caused a deadlock in the interactions with the O3 LSQ. The patche fixes the underlying issue by shifting the resetting of the flag to be done by the event that also calls sendRetry(). The patch also tidies up the flow control in recvTimingReq and ensures that we also check if we already have a retry outstanding.
2014-05-13cpu, mem: Make software prefetches non-blockingCurtis Dunham
Previously, they were treated so much like loads that they could stall at the head of the ROB. Now they are always treated like L1 hits. If they actually miss, a new request is created at the L1 and tracked from the MSHRs there if necessary (i.e. if it didn't coalesce with an existing outstanding load).
2014-05-13mem: Refactor assignment of Packet typesCurtis Dunham
Put the packet type swizzling (that is currently done in a lot of places) into a refineCommand() member function.
2014-09-03x86: Flag instructions that call suspend as IsQuiesceMitch Hayenga
The o3 cpu relies upon instructions that suspend a thread context being flagged as "IsQuiesce". If they are not, unpredictable behavior can occur. This patch fixes that for the x86 ISA.
2014-09-03cpu: Fix o3 drain bugMitch Hayenga
For X86, the o3 CPU would get stuck with the commit stage not being drained if an interrupt arrived while drain was pending. isDrained() makes sure that pcState.microPC() == 0, thus ensuring that we are at an instruction boundary. However, when we take an interrupt we execute: pcState.upc(romMicroPC(entry)); pcState.nupc(romMicroPC(entry) + 1); tc->pcState(pcState); As a result, the MicroPC is no longer zero. This patch ensures the drain is delayed until no interrupts are present. Once draining, non-synchronous interrupts are deffered until after the switch.
2014-09-03arm: Fix v8 neon latency issue for loads/storesMitch Hayenga
Neon memory ops that operate on multiple registers currently have very poor performance because of interleave/deinterleave micro-ops. This patch marks the deinterleave/interleave micro-ops as "No_OpClass" such that they take minumum cycles to execute and are never resource constrained. Additionaly the micro-ops over-read registers. Although one form may need to read up to 20 sources, not all do. This adds in new forms so false dependencies are not modeled. Instructions read their minimum number of sources.
2014-04-29arm: use condition code registers for ARM ISACurtis Dunham
Analogous to ee049bf (for x86). Requires a bump of the checkpoint version and corresponding upgrader code to move the condition code register values to the new register file.
2014-09-03arm: ISA X31 destination register fixAndrew Bardsley
This patch substituted the zero register for X31 used as a destination register. This prevents false dependencies based on X31.
2014-09-03cpu: fix bimodal predictor to use correct global history regDam Sunwoo
A small bug in the bimodal predictor caused significant degradation in performance on some benchmarks. This was caused by using the wrong globalHistoryReg during the update phase. This patches fixes the bug and brings the performance to normal level.
2014-09-03arm: Mark v7 cbz instructions as direct branchesMitch Hayenga
v7 cbz/cbnz instructions were improperly marked as indirect branches.
2014-09-03cpu: Fix cache blocked load behavior in o3 cpuMitch Hayenga
This patch fixes the load blocked/replay mechanism in the o3 cpu. Rather than flushing the entire pipeline, this patch replays loads once the cache becomes unblocked. Additionally, deferred memory instructions (loads which had conflicting stores), when replayed would not respect the number of functional units (only respected issue width). This patch also corrects that. Improvements over 20% have been observed on a microbenchmark designed to exercise this behavior.
2014-09-03cpu: Fix o3 quiesce fetch bugMitch Hayenga
O3 is supposed to stop fetching instructions once a quiesce is encountered. However due to a bug, it would continue fetching instructions from the current fetch buffer. This is because of a break statment that only broke out of the first of 2 nested loops. It should have broken out of both.
2014-09-03cpu: Fix SMT scheduling issue with the O3 cpuMitch Hayenga
The o3 cpu could attempt to schedule inactive threads under round-robin SMT mode. This is because it maintained an independent priority list of threads from the active thread list. This priority list could be come stale once threads were inactive, leading to the cpu trying to fetch/commit from inactive threads. Additionally the fetch queue is now forcibly flushed of instrctuctions from the de-scheduled thread. Relevant output: 24557000: system.cpu: [tid:1]: Calling deactivate thread. 24557000: system.cpu: [tid:1]: Removing from active threads list 24557500: system.cpu: FullO3CPU: Ticking main, FullO3CPU. 24557500: system.cpu.fetch: Running stage. 24557500: system.cpu.fetch: Attempting to fetch from [tid:1]
2014-09-03cpu: Fix incorrect speculative branch predictor behaviorMitch Hayenga
When a branch mispredicted gem5 would squash all history after and including the mispredicted branch. However, the mispredicted branch is still speculative and its history is required to rollback state if another, older, branch mispredicts. This leads to things like RAS corruption.
2014-09-03cpu: Add a fetch queue to the o3 cpuMitch Hayenga
This patch adds a fetch queue that sits between fetch and decode to the o3 cpu. This effectively decouples fetch from decode stalls allowing it to be more aggressive, running futher ahead in the instruction stream.
2014-09-03cpu: Fix o3 front-end pipeline interlock behaviorMitch Hayenga
The o3 pipeline interlock/stall logic is incorrect. o3 unnecessicarily stalled fetch and decode due to later stages in the pipeline. In general, a stage should usually only consider if it is stalled by the adjacent, downstream stage. Forcing stalls due to later stages creates and results in bubbles in the pipeline. Additionally, o3 stalled the entire frontend (fetch, decode, rename) on a branch mispredict while the ROB is being serially walked to update the RAT (robSquashing). Only should have stalled at rename.
2014-09-03cpu: Change writeback modeling for outstanding instructionsMitch Hayenga
As highlighed on the mailing list gem5's writeback modeling can impact performance. This patch removes the limitation on maximum outstanding issued instructions, however the number that can writeback in a single cycle is still respected in instToCommit().
2014-09-03arch: Properly guess OpClass from optional StaticInst flagsMitch Hayenga
isa_parser.py guesses the OpClass if none were given based upon the StaticInst flags. The existing code does not take into account optionally set flags. This code hoists the setting of optional flags so OpClass is properly assigned.
2014-09-03cache: Fix handling of LL/SC requests under contentionGeoffrey Blake
If a set of LL/SC requests contend on the same cache block we can get into a situation where CPUs will deadlock if they expect a failed SC to supply them data. This case happens where 3 or more cores are contending for a cache block using LL/SC and the system is configured where 2 cores are connected to a local bus and the third is connected to a remote bus. If a core on the local bus sends an SCUpgrade and the core on the remote bus sends and SCUpgrade they will race to see who will win the SC access. In the meantime if the other core appends a read to one of the SCUpgrades it will expect to be supplied data by that SCUpgrade transaction. If it happens that the SCUpgrade that was picked to supply the data is failed, it will drop the appended request for data and never respond, leaving the requesting core to deadlock. This patch makes all SC's behave as normal stores to prevent this case but still makes sure to check whether it can perform the update.
2014-05-27arm: support 16kb vm granulesCurtis Dunham
2014-09-03mem: Packet queue clean upAndreas Hansson
No change in functionality, just a bit of tidying up.
2014-09-03dev: Avoid invalid sized reads in PL390 with DPRINTF enabledMitch Hayenga
The first DPRINTF() in PL390::writeDistributor always read a uint32_t, though a packet may have only been 1 or 2 bytes. This caused an assertion in packet->get().
2014-09-03sim: Fix checkpoint restore for TickedAndrew Bardsley
This patch makes restoring the 'lastStopped' value for Ticked-containing objects (including MinorCPU) optional so that Ticked-containing objects can be restored from non-Ticked-containing objects (such as AtomicSimpleCPU).
2014-09-03arch, cpu: Factor out the ExecContext into a proper base classAndreas Sandberg
We currently generate and compile one version of the ISA code per CPU model. This is obviously wasting a lot of resources at compile time. This changeset factors out the interface into a separate ExecContext class, which also serves as documentation for the interface between CPUs and the ISA code. While doing so, this changeset also fixes up interface inconsistencies between the different CPU models. The main argument for using one set of ISA code per CPU model has always been performance as this avoid indirect branches in the generated code. However, this argument does not hold water. Booting Linux on a simulated ARM system running in atomic mode (opt/10.linux-boot/realview-simple-atomic) is actually 2% faster (compiled using clang 3.4) after applying this patch. Additionally, compilation time is decreased by 35%.
2014-09-03arch: Cleanup unused ISA traits constantsAndreas Hansson
This patch prunes unused values, and also unifies how the values are defined (not using an enum for ALPHA), aligning the use of int vs Addr etc. The patch also removes the duplication of PageBytes/PageShift and VMPageSize/LogVMPageSize. For all ISAs the two pairs had identical values and the latter has been removed.
2014-09-03config: Change parsing of Addr so hex values work from scriptsMitch Hayenga
When passed from a configuration script with a hexadecimal value (like "0x80000000"), gem5 would error out. This is because it would call "toMemorySize" which requires the argument to end with a size specifier (like 1MB, etc). This modification makes it so raw hex values can be passed through Addr parameters from the configuration scripts.
2014-09-03arm: Fix ExtMachInst hash operator underlying typeAndreas Hansson
This patch fixes the hash operator used for ARM ExtMachInst, which incorrectly was still using uint32_t. Instead of changing it to uint64_t it is not using the underlying data type of the BitUnion.
2014-09-01ruby: remove typedef of Index as int64Nilay Vaish
The Index type defined as typedef int64 does not really provide any help since in most places we use primitive types instead of Index. Also, the name Index is very generic that it does not merit being used as a typename.
2014-09-01x86: set op class of two fp instructionsNilay Vaish
This patch sets op class of two fp instructions: movfp and pop x87 stack as IntAluOp since these instructions do not make use of the fp alu.
2014-09-01ruby: PerfectSwitch: moves code to a per vnet helper functionNilay Vaish
This patch moves code from the wakeup() function to a operateVnet(). The aim is to improve the readiblity of the code.
2014-09-01ruby: message buffers: significant changesNilay Vaish
This patch is the final patch in a series of patches. The aim of the series is to make ruby more configurable than it was. More specifically, the connections between controllers are not at all possible (unless one is ready to make significant changes to the coherence protocol). Moreover the buffers themselves are magically connected to the network inside the slicc code. These connections are not part of the configuration file. This patch makes changes so that these connections will now be made in the python configuration files associated with the protocols. This requires each state machine to expose the message buffers it uses for input and output. So, the patch makes these buffers configurable members of the machines. The patch drops the slicc code that usd to connect these buffers to the network. Now these buffers are exposed to the python configuration system as Master and Slave ports. In the configuration files, any master port can be connected any slave port. The file pyobject.cc has been modified to take care of allocating the actual message buffer. This is inline with how other port connections work.
2014-09-01build opts: add MI_example to NULL ISANilay Vaish
A later changeset changes the file src/python/swig/pyobject.cc to include a header file that includes a header file generated at build time depending on the PROTOCOL in use. Since NULL ISA was not specifying any protocol, this resulted in compilation problems. Hence, the changeset.
2014-09-01mem: change the namespace Message to ProtoMessageNilay Vaish
The namespace Message conflicts with the Message data type used extensively in Ruby. Since Ruby is being moved to the same Master/Slave ports based configuration style as the rest of gem5, this conflict needs to be resolved. Hence, the namespace is being renamed to ProtoMessage.
2014-09-01ruby: slicc: change the way configurable members are specifiedNilay Vaish
There are two changes this patch makes to the way configurable members of a state machine are specified in SLICC. The first change is that the data member declarations will need to be separated by a semi-colon instead of a comma. Secondly, the default value to be assigned would now use SLICC's assignment operator i.e. ':='.
2014-09-01ruby: slicc: improve the grammarNilay Vaish
This patch changes the grammar for SLICC so as to remove some of the redundant / duplicate rules. In particular rules for object/variable declaration and class member declaration have been unified. Similarly, the rules for a general function and a class method have been unified. One more change is in the priority of two rules. The first rule is on declaring a function with all the params typed and named. The second rule is on declaring a function with all the params only typed. Earlier the second rule had a higher priority. Now the first rule has a higher priority.
2014-09-01ruby: mesi three level: slight naming changes.Nilay Vaish
2014-09-01ruby: slicc: donot prefix machine name to variablesNilay Vaish
This changeset does away with prefixing of member variables of state machines with the identity of the machine itself.
2014-09-01ruby: remove unused toString() from AbstractControllerNilay Vaish
2014-09-01ruby: network: move getNumNodes() to base classNilay Vaish
All the implementations were doing the same things.
2014-09-01ruby: eliminate type TimeNilay Vaish
There is another type Time in src/base class which results in a conflict.
2014-09-01ruby: move files from ruby/system to ruby/structuresNilay Vaish
The directory ruby/system is crowded and unorganized. Hence, the files the hold actual physical structures, are being moved to the directory ruby/structures. This includes Cache Memory, Directory Memory, Memory Controller, Wire Buffer, TBE Table, Perfect Cache Memory, Timer Table, Bank Array. The directory ruby/systems has the glue code that holds these structures together. --HG-- rename : src/mem/ruby/system/MachineID.hh => src/mem/ruby/common/MachineID.hh rename : src/mem/ruby/buffers/MessageBuffer.cc => src/mem/ruby/network/MessageBuffer.cc rename : src/mem/ruby/buffers/MessageBuffer.hh => src/mem/ruby/network/MessageBuffer.hh rename : src/mem/ruby/buffers/MessageBufferNode.cc => src/mem/ruby/network/MessageBufferNode.cc rename : src/mem/ruby/buffers/MessageBufferNode.hh => src/mem/ruby/network/MessageBufferNode.hh rename : src/mem/ruby/system/AbstractReplacementPolicy.hh => src/mem/ruby/structures/AbstractReplacementPolicy.hh rename : src/mem/ruby/system/BankedArray.cc => src/mem/ruby/structures/BankedArray.cc rename : src/mem/ruby/system/BankedArray.hh => src/mem/ruby/structures/BankedArray.hh rename : src/mem/ruby/system/Cache.py => src/mem/ruby/structures/Cache.py rename : src/mem/ruby/system/CacheMemory.cc => src/mem/ruby/structures/CacheMemory.cc rename : src/mem/ruby/system/CacheMemory.hh => src/mem/ruby/structures/CacheMemory.hh rename : src/mem/ruby/system/DirectoryMemory.cc => src/mem/ruby/structures/DirectoryMemory.cc rename : src/mem/ruby/system/DirectoryMemory.hh => src/mem/ruby/structures/DirectoryMemory.hh rename : src/mem/ruby/system/DirectoryMemory.py => src/mem/ruby/structures/DirectoryMemory.py rename : src/mem/ruby/system/LRUPolicy.hh => src/mem/ruby/structures/LRUPolicy.hh rename : src/mem/ruby/system/MemoryControl.cc => src/mem/ruby/structures/MemoryControl.cc rename : src/mem/ruby/system/MemoryControl.hh => src/mem/ruby/structures/MemoryControl.hh rename : src/mem/ruby/system/MemoryControl.py => src/mem/ruby/structures/MemoryControl.py rename : src/mem/ruby/system/MemoryNode.cc => src/mem/ruby/structures/MemoryNode.cc rename : src/mem/ruby/system/MemoryNode.hh => src/mem/ruby/structures/MemoryNode.hh rename : src/mem/ruby/system/MemoryVector.hh => src/mem/ruby/structures/MemoryVector.hh rename : src/mem/ruby/system/PerfectCacheMemory.hh => src/mem/ruby/structures/PerfectCacheMemory.hh rename : src/mem/ruby/system/PersistentTable.cc => src/mem/ruby/structures/PersistentTable.cc rename : src/mem/ruby/system/PersistentTable.hh => src/mem/ruby/structures/PersistentTable.hh rename : src/mem/ruby/system/PseudoLRUPolicy.hh => src/mem/ruby/structures/PseudoLRUPolicy.hh rename : src/mem/ruby/system/RubyMemoryControl.cc => src/mem/ruby/structures/RubyMemoryControl.cc rename : src/mem/ruby/system/RubyMemoryControl.hh => src/mem/ruby/structures/RubyMemoryControl.hh rename : src/mem/ruby/system/RubyMemoryControl.py => src/mem/ruby/structures/RubyMemoryControl.py rename : src/mem/ruby/system/SparseMemory.cc => src/mem/ruby/structures/SparseMemory.cc rename : src/mem/ruby/system/SparseMemory.hh => src/mem/ruby/structures/SparseMemory.hh rename : src/mem/ruby/system/TBETable.hh => src/mem/ruby/structures/TBETable.hh rename : src/mem/ruby/system/TimerTable.cc => src/mem/ruby/structures/TimerTable.cc rename : src/mem/ruby/system/TimerTable.hh => src/mem/ruby/structures/TimerTable.hh rename : src/mem/ruby/system/WireBuffer.cc => src/mem/ruby/structures/WireBuffer.cc rename : src/mem/ruby/system/WireBuffer.hh => src/mem/ruby/structures/WireBuffer.hh rename : src/mem/ruby/system/WireBuffer.py => src/mem/ruby/structures/WireBuffer.py rename : src/mem/ruby/recorder/CacheRecorder.cc => src/mem/ruby/system/CacheRecorder.cc rename : src/mem/ruby/recorder/CacheRecorder.hh => src/mem/ruby/system/CacheRecorder.hh
2014-08-28mem: adding architectural page table support for SE modeAlexandru
This patch enables the use of page tables that are stored in system memory and respect x86 specification, in SE mode. It defines an architectural page table for x86 as a MultiLevelPageTable class and puts a placeholder class for other ISAs page tables, giving the possibility for future implementation.
2014-04-01mem: adding a multi-level page table classAlexandru
This patch defines a multi-level page table class that stores the page table in system memory, consistent with ISA specifications. In this way, cpu models that use the actual hardware to execute (e.g. KvmCPU), are able to traverse the page table.
2014-08-26mem: Fix DRAMSim2 cycle check when restoring from checkpointAndreas Hansson
This patch ensures the cycle check is still valid even restoring from a checkpoint. In this case the DRAMSim2 cycle count is relative to the startTick rather than 0.
2014-08-26base: Add const to intmath and be more flexible with typingAndreas Hansson
This patch ensures the functions can be used on const variables.