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2016-03-17mem: Adjust cache queue reserve to more conservative valuesAndreas Hansson
The cache queue reserve is there as an overflow to give us enough headroom based on when we block the cache, and how many transactions we may already have accepted before actually blocking. The previous values were probably chosen to be "big enough", when we actually know that we check the MSHRs after every single allocation, and for the write buffers we know that we implicitly may need one entry for every outstanding MSHR. * * * mem: Adjust cache queue reserve to more conservative values The cache queue reserve is there as an overflow to give us enough headroom based on when we block the cache, and how many transactions we may already have accepted before actually blocking. The previous values were probably chosen to be "big enough", when we actually know that we check the MSHRs after every single allocation, and for the write buffers we know that we implicitly may need one entry for every outstanding MSHR.
2016-03-17mem: Create a separate class for the cache write bufferAndreas Hansson
This patch breaks out the cache write buffer into a separate class, without affecting any stats. The goal of the patch is to avoid encumbering the much-simpler write queue with the complex MSHR handling. In a follow on patch this simplification allows us to implement write combining. The WriteQueue gets its own class, but shares a common ancestor, the generic Queue, with the MSHRQueue.
2015-08-10mem, cpu: Add assertions to snoop invalidation logicStephan Diestelhorst
This patch adds assertions that enforce that only invalidating snoops will ever reach into the logic that tracks in-order load completion and also invalidation of LL/SC (and MONITOR / MWAIT) monitors. Also adds some comments to MSHR::replaceUpgrades().
2016-02-24mem: Ensure that InvalidateReq is not forwarded as ReadExReqAndreas Hansson
This patch fixes an issue where an InvalidationReq only traversed one level of the cache hierarchy, and was subsequently turned into a ReadExReq due to it needing writable, and the command not being checked for explicitly.
2016-02-23scons: Add missing override to appease clangAndreas Hansson
Make clang happy...again.
2016-02-18ruby: move range change send from RubyPort to derived classes.Tony Gutierrez
2016-02-17ruby: send address ranges from RubyPortTony Gutierrez
2016-02-15misc: Add missing overrides to appease clangAndreas Hansson
Since the last round of fixes a few new issues have snuck in. We should consider switching the regression runs to clang.
2016-02-15mem: Avoid using invalid iterator in cache lock list traversalAndreas Hansson
Fix up issue highlighted by Valgrind and the clang Address Sanitizer.
2016-02-14ruby: make DMASequencer inherit from RubyPortMichael LeBeane
This patch essentially rolls back 10518:30e3715c9405 to make RubyPort the parent class of DMASequencer. It removes redundant code and restores some features which were lost when directly inheriting from MemObject. For example, DMASequencer can now communicate to other devices using PIO, which is useful for memmory-mapped communication between multiple DMADevices.
2016-02-10mem: Be less conservative in clearing load locks in the cacheAndreas Hansson
Avoid being overly conservative in clearing load locks in the cache, and allow writes to the line if they are from the same context. This is in line with ALPHA and ARM.
2016-02-10mem: Move the point of coherency to the coherent crossbarAndreas Hansson
This patch introduces the ability of making the coherent crossbar the point of coherency. If so, the crossbar does not forward packets where a cache with ownership has already committed to responding, and also does not forward any coherency-related packets that are not intended for a downstream memory controller. Thus, invalidations and upgrades are turned around in the crossbar, and the memory controller only sees normal reads and writes. In addition this patch moves the express snoop promotion of a packet to the crossbar, thus allowing the downstream cache to check the express snoop flag (as it should) for bypassing any blocking, rather than relying on whether a cache is responding or not.
2016-02-10mem: Align cache behaviour in atomic when upstream is respondingAndreas Hansson
Adopt the same flow as in timing mode, where the caches on the path to memory get to keep the line (if present), and we use the responderHadWritable flag to determine if we need to forward the (invalidating) packet or not.
2016-02-10mem: Align how snoops are handled when hitting writebacksAndreas Hansson
This patch unifies the snoop handling in case of hitting writebacks with how we handle snoops hitting in the tags. As a result, we end up using the same optimisation as the normal snoops, where we inform the downstream cache if we encounter a line in Modified (writable and dirty) state, which enables us to avoid sending out express snoops to invalidate any Shared copies of the line. A few regressions consequently change, as some transactions are sunk higher up in the cache hierarchy.
2016-02-10mem: Deduce if cache should forward snoopsAndreas Hansson
This patch changes how the cache determines if snoops should be forwarded from the memory side to the CPU side. Instead of having a parameter, the cache now looks at the port connected on the CPU side, and if it is a snooping port, then snoops are forwarded. Less error prone, and less parameters to worry about. The patch also tidies up the CPU classes to ensure that their I-side port is not snooping by removing overrides to the snoop request handler, such that snoop requests will panic via the default MasterPort implement
2016-02-06style: eliminate explicit boolean comparisonsSteve Reinhardt
Result of running 'hg m5style --skip-all --fix-control -a' to get rid of '== true' comparisons, plus trivial manual edits to get rid of '== false'/'== False' comparisons. Left a couple of explicit comparisons in where they didn't seem unreasonable: invalid boolean comparison in src/arch/mips/interrupts.cc:155 >> DPRINTF(Interrupt, "Interrupts OnCpuTimerINterrupt(tc) == true\n");<< invalid boolean comparison in src/unittest/unittest.hh:110 >> "EXPECT_FALSE(" #expr ")", (expr) == false)<<
2016-02-06style: fix missing spaces in control statementsSteve Reinhardt
Result of running 'hg m5style --skip-all --fix-control -a'.
2016-02-06style: remove trailing whitespaceSteve Reinhardt
Result of running 'hg m5style --skip-all --fix-white -a'.
2016-01-22ruby: removed Write_Only AccessPermissionBrad Beckmann
2015-07-20ruby: split CPU and GPU latency statsDavid Hashe
2016-01-19gpu-compute: AMD's baseline GPU modelTony Gutierrez
2016-01-19mem: write combining for ruby protocolsTony Gutierrez
This patch adds support for write-combining in ruby.
2016-01-19* * *Tony Gutierrez
mem: support for gpu-style RMWs in ruby This patch adds support for GPU-style read-modify-write (RMW) operations in ruby. Such atomic operations are traditionally executed at the memory controller (instead of through an L1 cache using cache-line locking). Currently, this patch works by propogating operation functors through the memory system.
2015-07-20mem: misc flags for AMD gpu modelBlake Hechtman
This patch add support to mark memory requests/packets with attributes defined in HSA, such as memory order and scope.
2016-01-11mem: fix bug in packet access endianness changesSteve Reinhardt
The new Packet::setRaw() method incorrectly still contained an htog() conversion. As a result, calls to the old set() method (now defined as setRaw(htog(v))) underwent two htog conversions, which breaks things when htog() is not a no-op. Interestingly the only test that caught this was a SPARC boot test, where an IsaFake device with a non-zero return value was getting swapped twice resulting in a register getting loaded with 0x100000000000000 instead of 1. (Good reason for keeping SPARC around, perhaps?)
2016-01-11scons: Enable -Wextra by defaultAndreas Hansson
Make best use of the compiler, and enable -Wextra as well as -Wall. There are a few issues that had to be resolved, but they are all trivial.
2015-12-31mem: add CacheVerbose debug flag, filter noisy DPRINTFsSteve Reinhardt
Some of the DPRINTFs added to the classic cache in cset 45df88079f04, while useful to those unfamiliar with the cache code, end up being noise when you're familiar with the code but are trying to debug tricky protocol issues. (Particularly getting two messages from each cache as it receives a snoop request then declares that there was no match.) This patch introduces a CacheVerbose debug flag, and moves a subset of the added DPRINTFs into that category, so that Cache by itself returns to being a more succinct summary of cache activity. Also added a CacheAll compound flag to turn on all the cache-related debug flags (other than CacheTags, which you *really* have to want badly to turn it on, IMO).
2015-12-31mem: Do not rely on the NeedsWritable flag for responsesAndreas Hansson
This patch removes the NeedsWritable flag for all responses, as it is really only the request that needs a writable response. The response, on the other hand, should in these cases always provide the line in a writable state, as indicated by the hasSharers flag not being set. When we send requests that has NeedsWritable set, the response will always have the hasSharers flag not set. Additionally, there are cases where the request did not have NeedsWritable set, and we still get a writable response with the hasSharers flag not set. This never happens on snoops, but is used by downstream caches to pass ownership upstream. As part of this patch, the affected response types are updated, and the snoop filter is similarly modified to check only the hasSharers flag (as it should). A sanity check is also added to the packet class, asserting that we never look at the NeedsWritable flag for responses. No regressions are affected.
2015-12-31mem: Do not allocate space for packet data if not neededAndreas Hansson
This patch looks at the request and response command to determine if either actually has any data payload, and if not, we do not allocate any space for packet data. The only tricky case is where the command type is changed as part of the MSHR functionality. In these cases where the original packet had no data, but the new packet does, we need to explicitly call allocate().
2015-12-31mem: Do not alter cache block state on uncacheable snoopsAndreas Hansson
This patch ensures we do not respond with a Modified (dirty and writable) line if the request is uncacheable, and that the cache responding retains the line without modifying the state (even if responding).
2015-12-31mem: Make cache terminology easier to understandAndreas Hansson
This patch changes the name of a bunch of packet flags and MSHR member functions and variables to make the coherency protocol easier to understand. In addition the patch adds and updates lots of descriptions, explicitly spelling out assumptions. The following name changes are made: * the packet memInhibit flag is renamed to cacheResponding * the packet sharedAsserted flag is renamed to hasSharers * the packet NeedsExclusive attribute is renamed to NeedsWritable * the packet isSupplyExclusive is renamed responderHadWritable * the MSHR pendingDirty is renamed to pendingModified The cache states, Modified, Owned, Exclusive, Shared are also called out in the cache and MSHR code to make it easier to understand.
2015-07-20ruby: slicc: have a static MachineTypeTony Gutierrez
This patch is imported from reviewboard patch 2551 by Nilay. This patch moves from a dynamically defined MachineType to a statically defined one. The need for this patch was felt since a dynamically defined type prevents us from having types for which no machine definition may exist. The following changes have been made: i. each machine definition now uses a type from the MachineType enumeration instead of any random identifier. This required changing the grammar and the *.sm files. ii. MachineType enumeration defined statically in RubySlicc_Exports.sm. * * * normal protocol fixes for nilay's parser machine type fix
2015-07-20ruby: slicc: remove support for single machine, multiple typesTony Gutierrez
This patch is imported from reviewboard patch 2550 by Nilay. It was possible to specify multiple machine types with a single state machine. This seems unnecessary and is being removed.
2015-12-28mem: Explicitly check MSHR snoops for cases not dealt withAndreas Hansson
Add a sanity check to make it explicit that we currently do not allow an I/O coherent agent to directly issue writes into the coherent part of the memory system (it has to go via a cache, and get transformed into a read ex, upgrade or invalidation).
2015-12-28mem: Remove unused cache squash functionalityAndreas Hansson
This patch removes the unused squash function from the MSHR queue, and the associated (and also unused) threadNum member from the MSHR.
2015-12-28mem: Avoid unecessary checks when creating HardPFReq in cacheAndreas Hansson
The checks made before sending out a HardPFReq were unecessarily complex, and checked for cases that never occur. This patch tidies it up.
2015-12-28mem: Do not use sender state to track forwarded snoops in cacheAndreas Hansson
This patch changes how the cache tracks which snoops are forwarded, and which ones are created locally. Previously the identification was based on an empty sender state of a specific class, but this method fails to distinguish which cache actually attached the sender state. Instead we use the same mechanism as the crossbar, and keep track of the requests that have outstanding snoops.
2015-12-28mem: Fix cache sender state handling and add clarificationAndreas Hansson
This patch addresses a bug in how the cache attached the MSHR as a sender state. Rather than overwriting any existing sender state it now pushes a new one. The handling of upward snoops is also clarified.
2015-12-17mem: Fix memory allocation bug in deferred snoop handlingAndreas Hansson
This patch fixes a corner case in the deferred snoop handling, where requests ended up being used by multiple packets with different lifetimes, and inadvertently got deleted while they were still in use.
2015-07-20mem: add request types for acquire and releaseDavid Hashe
Add support for acquire and release requests. These synchronization operations are commonly supported by several modern instruction sets.
2015-07-20ruby: more flexible ruby tester supportBrad Beckmann
This patch allows the ruby random tester to use ruby ports that may only support instr or data requests. This patch is similar to a previous changeset (8932:1b2c17565ac8) that was unfortunately broken by subsequent changesets. This current patch implements the support in a more straight-forward way. Since retries are now tested when running the ruby random tester, this patch splits up the retry and drain check behavior so that RubyPort children, such as the GPUCoalescer, can perform those operations correctly without having to duplicate code. Finally, the patch also includes better DPRINTFs for debugging the tester.
2015-12-09mem: remove acq/rel cmds from packet and add mem fence reqTony Gutierrez
2015-12-07cpu: Support virtual addr in elastic tracesRadhika Jagtap
This patch adds support to optionally capture the virtual address and asid for load/store instructions in the elastic traces. If they are present in the traces, Trace CPU will set those fields of the request during replay.
2015-12-07mem: Add instruction sequence number to requestRadhika Jagtap
This patch adds the instruction sequence number to the request and provides a request constructor that accepts a sequence number for initialization.
2015-11-25mem: Fix search-replace issues in DRAMPower wrapper licenseAndreas Hansson
Fix a number of unintentional insertions of 'const'.
2015-11-15arm: Add missing explicit overrides for classic cachesAndreas Sandberg
Make clang when compiling on OSX.
2015-07-20ruby: added stl vector of ints to be used by SLICCBrad Beckmann
2015-11-13slicc: fixes for the Address to Addr changeset (11025)Tony Gutierrez
misc changes now that Address has become Addr including int to address util function
2015-11-13ruby: add BoolVecJoe Gross
The BoolVec typedef and insertion operator overload function simplify usage of vectors of type bool
2015-07-20mem: add boolean to disable PacketQueue's size sanity checkBrad Beckmann
the sanity check, while generally useful for exposing memory system bugs, may be spurious with respect to GPU workloads, which may generate many more requests than typical CPU workloads. the large number of requests generated by the GPU may cause the req/resp queues to back up, thus queueing more than 100 packets.