As of now, the enqueue statement can take in any number of 'pairs' as
argument. But we only use the pair in which latency is the key. This
latency is allowed to be either a fixed integer or a member variable of
controller in which the expression appears. This patch drops the use of pairs
in an enqueue statement. Instead, an expression is allowed which will be
interpreted to be the latency of the enqueue. This expression can anything
allowed by slicc including a constant integer or a member variable.
Two files had been incorrectly named with a .cache suffix.
--HG--
rename : src/mem/protocol/MESI_Three_Level-L0.cache => src/mem/protocol/MESI_Three_Level-L0cache.sm
rename : src/mem/protocol/MESI_Three_Level-L1.cache => src/mem/protocol/MESI_Three_Level-L1cache.sm
The first two levels (L0, L1) are private to the core, the third level (L2)is
possibly shared. The protocol supports clustered designs. For example, one
can have two sets of two cores. Each core has an L0 and L1 cache. There are
two L2 controllers where each set accesses only one of the L2 controllers.
A cluster over here means a set of controllers that can be accessed only by a
certain set of cores. For example, consider a two level hierarchy. Assume
there are 4 L1 controllers (private) and 2 L2 controllers. We can have two
different hierarchies here:
a. the address space is partitioned between the two L2 controllers. Each L1
controller accesses both the L2 controllers. In this case, each L1 controller
is a cluster initself.
b. both the L2 controllers can cache any address. An L1 controller has access
to only one of the L2 controllers. In this case, each L2 controller
along with the L1 controllers that access it, form a cluster.
This patch allows for each controller to have a cluster ID, which is 0 by
default. By setting the cluster ID properly, one can instantiate hierarchies
with clusters. Note that the coherence protocol might have to be changed as
well.
This patch fixes couple of bugs in the L2 controller of the mesi cmp
directory protocol.
1. The state MT_I was transitioning to NP on receiving a clean writeback
from the L1 controller. This patch makes it inform the directory controller
about the writeback.
2. The L2 controller was sending the dirty bit to the L1 controller and the
L2 controller used writeback from the L1 controller to update the dirty bit
unconditionally. Now, the L1 controller always assumes that the incoming
data is clean. The L2 controller updates the dirty bit only when the L1
controller writes to the block.
3. Certain unused functions and events are being removed.
The directory controller should not have the sharer field since there is
only one level 2 cache. Anyway the field was not in use. The owner field
was being used to track the l2 cache version (in case of distributed l2) that
has the cache block under consideration. The information is not required
since the version of the level 2 cache can be obtained from a subset of the
address bits.
This patch adds missing initializations of the SenderMachine field of
out_msg's when thery are created in the L2 cache controller of the
MOESI_CMP_directory coherence protocol. When an out_msg is created and this
field is left uninitialized, it is set to the default value MachineType_NUM.
This causes a panic in the MachineType_to_string function when gem5 is
executed with the Ruby debug flag on and it tries to print the message.
Committed by: Nilay Vaish <nilay@cs.wisc.edu>
This patch adds separate actions for requests that missed in the local cache
and messages were sent out to get the requested line. These separate actions
are required for differentiating between the hit and miss latencies in the
statistics collected.
This patch adds separate actions for requests that missed in the local cache
and messages were sent out to get the requested line. These separate actions
are required for differentiating between the hit and miss latencies in the
statistics collected.
The patch started of with removing the global variables from the profiler for
profiling the miss latency of requests made to the cache. The corrresponding
histograms have been moved to the Sequencer. These are combined together when
the histograms are printed. Separate histograms are now maintained for
tracking latency of all requests together, of hits only and of misses only.
A particular set of histograms used to use the type GenericMachineType defined
in one of the protocol files. This patch removes this type. Now, everything
that relied on this type would use MachineType instead. To do this, SLICC has
been changed so that multiple machine types can be declared by a controller
in its preamble.
This patch removes the following three files: RubySlicc_Profiler.sm,
RubySlicc_Profiler_interface.cc and RubySlicc_Profiler_interface.hh.
Only one function prototyped in the file RubySlicc_Profiler.sm. Rest of the
code appearing in any of these files is not in use. Therefore, these files
are being removed.
That one single function, profileMsgDelay(), is being moved to the protocol
files where it is in use. If we need any of these deleted functions, I think
the right way to make them visible is to have the AbstractController class in
a .sm and let the controller state machine inherit from this class. The
AbstractController class can then have the prototypes of these profiling
functions in its definition.
Change all occurrances of Address as a variable name to instead use Addr.
Address is an allowed name in slicc even when Address is also being used as a
type, leading to declarations of "Address Address". While this works, it
prevents adding another field of type Address because the compiler then thinks
Address is a variable name, not type.
Committed by: Nilay Vaish <nilay@cs.wisc.edu>
This patch changes the way cache statistics are collected in ruby.
As of now, there is separate entity called CacheProfiler which holds
statistical variables for caches. The CacheMemory class defines different
functions for accessing the CacheProfiler. These functions are then invoked
in the .sm files. I find this approach opaque and prone to error. Secondly,
we probably should not be paying the cost of a function call for recording
statistics.
Instead, this patch allows for accessing statistical variables in the
.sm files. The collection would become transparent. Secondly, it would happen
in place, so no function calls. The patch also removes the CacheProfiler class.
--HG--
rename : src/mem/slicc/ast/InfixOperatorExprAST.py => src/mem/slicc/ast/OperatorExprAST.py
The MESI CMP directory coherence protocol, while transitioning from SM to IM,
did not invalidate the lock that it might have taken on a cache line. This
patch adds an action for doing so.
The problem was found by Dibakar, but I was not happy with his proposed
solution. So I implemented a different solution.
Committed by: Nilay Vaish <nilay@cs.wisc.edu>
The transition for state MII and event Store was found missing during testing.
The transition is being added. The controller will not stall the Store request
in state MII
This patch is as of now the final patch in the series of patches that replace
Time with Cycles.This patch further replaces Time with Cycles in Sequencer,
Profiler, different protocols and related entities.
Though Time has not been completely removed, the places where it is in use
seem benign as of now.
The patch started of with replacing Time with Cycles in the Consumer class.
But to get ruby to compile, the rest of the changes had to be carried out.
Subsequent patches will further this process, till we completely replace
Time with Cycles.
This patch does several things. First, the counter for fully busy cycles for a
controller is now kept with in the controller, instead of being part of the profiler.
Second, the topology class no longer keeps an array of controllers which was only
used for printing stats. Instead, ruby system will now ask each controller to print
the stats. Thirdly, the statistical variable for recording how many different types
were created is being moved in to the controller from the profiler. Note that for
printing, the profiler will collate results from different controllers.
Many Ruby structures inherit from the Consumer, which is used for scheduling
events. The Consumer used to relay on an Event Manager for scheduling events
and on g_system_ptr for time. With this patch, the Consumer will now use a
ClockedObject to schedule events and to query for current time. This resulted
in several structures being converted from SimObjects to ClockedObjects. Also,
the MessageBuffer class now requires a pointer to a ClockedObject so as to
query for time.
The patch adds support to slicc for recognizing arguments that should be
passed to the constructor of a class. I did not like the fact that an explicit
check was being carried on the type 'TBETable' to figure out the arguments to
be passed to the constructor.
The patch also moves some of the member variables that are declared for all
the controllers to the base class AbstractController.
I had forgotten to change the network test protocol while making changes to
ruby for supporting functional accesses. This patch updates the protocol so
that it can compile correctly.
This patch adds support to different entities in the ruby memory system
for more reliable functional read/write accesses. Only the simple network
has been augmented as of now. Later on Garnet will also support functional
accesses.
The patch adds functional access code to all the different types of messages
that protocols can send around. These messages are functionally accessed
by going through the buffers maintained by the network entities.
The patch also rectifies some of the bugs found in coherence protocols while
testing the patch.
With this patch applied, functional writes always succeed. But functional
reads can still fail.
This patch adds support for function definitions to appear in slicc structs.
This is required for supporting functional accesses for different types of
messages. Subsequent patches will use this to development.
This patch models a cache as separate tag and data arrays. The patch exposes
the banked array as another resource that is checked by SLICC before a
transition is allowed to execute. This is similar to how TBE entries and slots
in output ports are modeled.
Updates to Ruby to support statistics counting of cache accesses. This feature
serves multiple purposes beyond simple stats collection. It provides the
foundation for ruby to model the cache tag and data arrays as physical
resources, as well as provide the necessary input data for McPAT power
modeling.
