Commit graph

1590 commits

Author SHA1 Message Date
Geoffrey Blake
b404ffde60 cache: Fix handling of LL/SC requests under contention
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.
2014-09-03 07:42:31 -04:00
Andreas Hansson
77c28cc395 mem: Packet queue clean up
No change in functionality, just a bit of tidying up.
2014-09-03 07:42:28 -04:00
Andreas Hansson
e1ac962939 arch: Cleanup unused ISA traits constants
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.
2014-09-03 07:42:21 -04:00
Nilay Vaish
2cbe7c705b ruby: remove typedef of Index as int64
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.
2014-09-01 16:55:50 -05:00
Nilay Vaish
b4dade6fb2 ruby: PerfectSwitch: moves code to a per vnet helper function
This patch moves code from the wakeup() function to a operateVnet().
The aim is to improve the readiblity of the code.
2014-09-01 16:55:48 -05:00
Nilay Vaish
7a0d5aafe4 ruby: message buffers: significant changes
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.
2014-09-01 16:55:47 -05:00
Nilay Vaish
00286fc5cb build opts: add MI_example to NULL ISA
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.
2014-09-01 16:55:46 -05:00
Nilay Vaish
d07abd9b5b mem: change the namespace Message to ProtoMessage
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.
2014-09-01 16:55:46 -05:00
Nilay Vaish
cee8faaad0 ruby: slicc: change the way configurable members are specified
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. ':='.
2014-09-01 16:55:45 -05:00
Nilay Vaish
b1d3873ec5 ruby: slicc: improve the grammar
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.
2014-09-01 16:55:44 -05:00
Nilay Vaish
3202ec98e7 ruby: mesi three level: slight naming changes. 2014-09-01 16:55:44 -05:00
Nilay Vaish
557200725c ruby: slicc: donot prefix machine name to variables
This changeset does away with prefixing of member variables of state machines
with the identity of the machine itself.
2014-09-01 16:55:43 -05:00
Nilay Vaish
6ceb1aadc2 ruby: remove unused toString() from AbstractController 2014-09-01 16:55:42 -05:00
Nilay Vaish
00dbadcbb0 ruby: network: move getNumNodes() to base class
All the implementations were doing the same things.
2014-09-01 16:55:42 -05:00
Nilay Vaish
cc2cc58869 ruby: eliminate type Time
There is another type Time in src/base class which results in a conflict.
2014-09-01 16:55:41 -05:00
Nilay Vaish
82d136285d ruby: move files from ruby/system to ruby/structures
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
2014-09-01 16:55:40 -05:00
Alexandru
5efbb4442a mem: adding architectural page table support for SE mode
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.
2014-08-28 10:11:44 -05:00
Alexandru
26ac28dec2 mem: adding a multi-level page table class
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.
2014-04-01 12:18:12 -05:00
Andreas Hansson
9e4cd5bf1e mem: Fix DRAMSim2 cycle check when restoring from checkpoint
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.
2014-08-26 10:14:38 -04:00
Andreas Hansson
3efabb4b2f mem: Update DRAM controller comments
Update comments and add a reference for more information.
2014-08-26 10:13:03 -04:00
Andreas Hansson
56b7796e0d mem: Fix address interleaving bug in DRAM controller
This patch fixes a bug in the DRAM controller address decoding. In
cases where the DRAM burst size (e.g. 32 bytes in a rank with a single
LPDDR3 x32) was smaller than the channel interleaving size
(e.g. systems with a 64-byte cache line) one address bit effectively
got used as a channel bit when it should have been a low-order column
bit.

This patch adds a notion of "columns per stripe", and more clearly
deals with the low-order column bits and high-order column bits. The
patch also relaxes the granularity check such that it is possible to
use interleaving granularities other than the cache line size.

The patch also adds a missing M5_CLASS_VAR_USED to the tCK member as
it is only used in the debug build for now.
2014-08-26 10:12:45 -04:00
Mitch Hayenga
f6f6ae461e mem: Properly set cache block status fields on writebacks
When a cacheline is written back to a lower-level cache,
tags->insertBlock() sets various status parameters. However these
status bits were cleared immediately after calling. This patch makes
it so that these status fields are not cleared by moving them outside
of the tags->insertBlock() call.
2014-08-13 06:57:24 -04:00
Anthony Gutierrez
a628afedad mem: refactor LRU cache tags and add random replacement tags
this patch implements a new tags class that uses a random replacement policy.
these tags prefer to evict invalid blocks first, if none are available a
replacement candidate is chosen at random.

this patch factors out the common code in the LRU class and creates a new
abstract class: the BaseSetAssoc class. any set associative tag class must
implement the functionality related to the actual replacement policy in the
following methods:

accessBlock()
findVictim()
insertBlock()
invalidate()
2014-07-28 12:23:23 -04:00
Andreas Hansson
1f539ce4cc mem: DRAMPower trace output
This patch adds a DRAMPower flag to enable off-line DRAM power
analysis using the DRAMPower tool. A new DRAMPower flag is added
and a follow-on patch adds a Python script to post-process the output
and order it based on time stamps.

The long-term goal is to link DRAMPower as a library and provide the
commands through function calls to the model rather than first
printing and then parsing the commands. At the moment it is also up to
the user to ensure that the same DRAM configuration is used by the
gem5 controller model and DRAMPower.
2014-06-30 13:56:03 -04:00
Andreas Hansson
b4ce51eb9e mem: Add bank and rank indices as fields to the DRAM bank
This patch adds the index of the bank and rank as a field so that we can
determine the identity of a given bank (reference or pointer) for the
power tracing. We also grab the opportunity of cleaning up the
arguments used for identifying the bank when activating.
2014-06-30 13:56:02 -04:00
Andreas Hansson
d59bc8ee1f mem: Extend DRAM row bits from 16 to 32 for larger densities
This patch extends the DRAM row bits to 32 to support larger density
memories. Additional checks are also added to ensure the row fits in
the 32 bits.
2014-06-30 13:56:01 -04:00
Steve Reinhardt
0be64ffe2f style: eliminate equality tests with true and false
Using '== true' in a boolean expression is totally redundant,
and using '== false' is pretty verbose (and arguably less
readable in most cases) compared to '!'.

It's somewhat of a pet peeve, perhaps, but I had some time
waiting for some tests to run and decided to clean these up.

Unfortunately, SLICC appears not to have the '!' operator,
so I had to leave the '== false' tests in the SLICC code.
2014-05-31 18:00:23 -07:00
Nilay Vaish
e685767b58 ruby: slicc: remove unused ids DNUCA* 2014-05-23 06:07:02 -05:00
Nilay Vaish
9c9257a612 ruby: remove old protocol documentation 2014-05-23 06:07:02 -05:00
Nilay Vaish
8bf41e41c1 ruby: message buffer: drop dequeue_getDelayCycles()
The functionality of updating and returning the delay cycles would now be
performed by the dequeue() function itself.
2014-05-23 06:07:02 -05:00
Andreas Hansson
f800f268db mem: Update DDR3 and DDR4 based on datasheets
This patch makes a more firm connection between the DDR3-1600
configuration and the corresponding datasheet, and also adds a
DDR3-2133 and a DDR4-2400 configuration. At the moment there is also
an ongoing effort to align the choice of datasheets to what is
available in DRAMPower.
2014-05-09 18:58:49 -04:00
Andreas Hansson
cc4ca78f99 mem: Add DRAM cycle time
This patch extends the current timing parameters with the DRAM cycle
time. This is needed as the DRAMPower tool expects timestamps in DRAM
cycles. At the moment we could get away with doing this in a
post-processing step as the DRAMPower execution is separate from the
simulation run. However, in the long run we want the tool to be called
during the simulation, and then the cycle time is needed.
2014-05-09 18:58:49 -04:00
Andreas Hansson
8c56efe747 mem: Simplify DRAM response scheduling
This patch simplifies the DRAM response scheduling based on the
assumption that they are always returned in order.
2014-05-09 18:58:48 -04:00
Andreas Hansson
8e3869411d mem: Add precharge all (PREA) to the DRAM controller
This patch adds the basic ingredients for a precharge all operation,
to be used in conjunction with DRAM power modelling.

Currently we do not try and apply any cleverness when precharging all
banks, thus even if only a single bank is open we use PREA as opposed
to PRE. At the moment we only have a single tRP (tRPpb), and do not
model the slightly longer all-bank precharge constraint (tRPab).
2014-05-09 18:58:48 -04:00
Andreas Hansson
0ba1e72e9b mem: Remove printing of DRAM params
This patch removes the redundant printing of DRAM params.
2014-05-09 18:58:48 -04:00
Andreas Hansson
6753cb705e mem: Add tRTP to the DRAM controller
This patch adds the tRTP timing constraint, governing the minimum time
between a read command and a precharge. Default values are provided
for the existing DRAM types.
2014-05-09 18:58:48 -04:00
Andreas Hansson
60799dc552 mem: Merge DRAM latency calculation and bank state update
This patch merges the two control paths used to estimate the latency
and update the bank state. As a result of this merging the computation
is now in one place only, and should be easier to follow as it is all
done in absolute (rather than relative) time.

As part of this change, the scheduling is also refined to ensure that
we look at a sensible estimate of the bank ready time in choosing the
next request. The bank latency stat is removed as it ends up being
misleading when the DRAM access code gets evaluated ahead of time (due
to the eagerness of waking the model up for scheduling the next
request).
2014-05-09 18:58:48 -04:00
Andreas Hansson
b8631d9ae8 mem: Add tWR to DRAM activate and precharge constraints
This patch adds the write recovery time to the DRAM timing
constraints, and changes the current tRASDoneAt to a more generic
preAllowedAt, capturing when a precharge is allowed to take place.

The part of the DRAM access code that accounts for the precharge and
activate constraints is updated accordingly.
2014-05-09 18:58:48 -04:00
Andreas Hansson
c735ef6cb0 mem: Merge DRAM page-management calculations
This patch treats the closed page policy as yet another case of
auto-precharging, and thus merges the code with that used for the
other policies.
2014-05-09 18:58:48 -04:00
Andreas Hansson
87f4c956c4 mem: Add DRAM power states to the controller
This patch adds power states to the controller. These states and the
transitions can be used together with the Micron power model. As a
more elaborate use-case, the transitions can be used to drive the
DRAMPower tool.

At the moment, the power-down modes are not used, and this patch
simply serves to capture the idle, auto refresh and active modes. The
patch adds a third state machine that interacts with the refresh state
machine.
2014-05-09 18:58:48 -04:00
Andreas Hansson
babf072c1c mem: Ensure DRAM refresh respects timings
This patch adds a state machine for the refresh scheduling to
ensure that no accesses are allowed while the refresh is in progress,
and that all banks are propely precharged.

As part of this change, the precharging of banks of broken out into a
method of its own, making is similar to how activations are dealt
with. The idle accounting is also updated to ensure that the refresh
duration is not added to the time that the DRAM is in the idle state
with all banks precharged.
2014-05-09 18:58:48 -04:00
Andreas Hansson
5c2c3f598e mem: Make DRAM read/write switching less conservative
This patch changes the read/write event loop to use a single event
(nextReqEvent), along with a state variable, thus joining the two
control flows. This change makes it easier to follow the state
transitions, and control what happens when.

With the new loop we modify the overly conservative switching times
such that the write-to-read switch allows bank preparation to happen
in parallel with the bus turn around. Similarly, the read-to-write
switch uses the introduced tRTW constraint.
2014-05-09 18:58:48 -04:00
Mitch Hayenga
a15b713cba mem: Squash prefetch requests from downstream caches
This patch squashes prefetch requests from downstream caches,
so that they do not steal cachelines away from caches closer
to the cpu.  It was originally coded by Mitch Hayenga and
modified by Aasheesh Kolli.
2014-05-09 18:58:46 -04:00
Sascha Bischoff
e940bac278 mem: Auto-generate CommMonitor trace file names
Splits the CommMonitor trace_file parameter into three parameters. Previously,
the trace was only enabled if the trace_file parameter was set, and would be
written to this file. This patch adds in a trace_enable and trace_compress
parameter to the CommMonitor.

No trace is generated if trace_enable is set to False. If it is set to True, the
trace is written to a file based on the name of the SimObject in the simulation
hierarchy. For example, system.cluster.il1_commmonitor.trc. This filename can be
overridden by additionally specifying a file name to the trace_file parameter
(more on this later).

The trace_compress parameter will append .gz to any filename if set to True.
This enables compression of the generated traces. If the file name already ends
in .gz, then no changes are made.

The trace_file parameter will override the name set by the trace_enable
parameter. In the case that the specified name does not end in .gz but
trace_compress is set to true, .gz is appended to the supplied file name.
2014-05-09 18:58:46 -04:00
Mitch Hayenga
a0d30f36a6 mem: Don't print out the data of a cache block
This never actually worked since it was printing out only a word
of the cache block and not the entire thing and doubly didn't work
csprintf overrides the %#x specifier and assumes a char* array is
actually a string.
2014-04-01 14:24:36 -05:00
Nilay Vaish
4ceeda20aa ruby: slicc: remove old documentation
Has not been maintained at all.  Since there is alternate documentation
available on gem5.org, no need to have this separately.
2014-04-19 09:00:31 -05:00
Nilay Vaish
183100b8cb ruby: slicc: slight change to rule for transitions
It had an unnecessary pairs token which is being removed.
2014-04-19 09:00:31 -05:00
Marco Elver
d9fa950396 ruby: recorder: Fix (de-)serializing with different cache block-sizes
Upon aggregating records, serialize system's cache-block size, as the
cache-block size can be different when restoring from a checkpoint. This way,
we can correctly read all records when restoring from a checkpoints, even if
the cache-block size is different.

Note, that it is only possible to restore from a checkpoint if the
desired cache-block size is smaller or equal to the cache-block size
when the checkpoint was taken; we can split one larger request into
multiple small ones, but it is not reliable to do the opposite.

Committed by: Nilay Vaish <nilay@cs.wisc.edu>
2014-04-19 09:00:30 -05:00
Nilay Vaish
d805e42b81 ruby: slicc: change enqueue statement
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.
2014-04-08 13:26:30 -05:00
Nilay Vaish
e689c00b16 ruby: coherence protocols: drop the phrase IntraChip
The phrase is no longer valid since we do not distinguish between
inter and intra chip communication.
2014-04-08 13:26:29 -05:00
Andreas Hansson
a00383a40a mem: Track DRAM read/write switching and add hysteresis
This patch adds stats for tracking the number of reads/writes per bus
turn around, and also adds hysteresis to the write-to-read switching
to ensure that the queue does not oscilate around the low threshold.
2014-03-23 11:12:14 -04:00
Andreas Hansson
7c18691db1 mem: Rename SimpleDRAM to a more suitable DRAMCtrl
This patch renames the not-so-simple SimpleDRAM to a more suitable
DRAMCtrl. The name change is intended to ensure that we do not send
the wrong message (although the "simple" in SimpleDRAM was originally
intended as in cleverly simple, or elegant).

As the DRAM controller modelling work is being presented at ISPASS'14
our hope is that a broader audience will use the model in the future.

--HG--
rename : src/mem/SimpleDRAM.py => src/mem/DRAMCtrl.py
rename : src/mem/simple_dram.cc => src/mem/dram_ctrl.cc
rename : src/mem/simple_dram.hh => src/mem/dram_ctrl.hh
2014-03-23 11:12:12 -04:00
Andreas Hansson
3dd1587afc mem: Change memory defaults to be more representative
Make the default memory type DDR3-1600 x64, and use the open-adaptive
page policy. This change is aiming to ensure that users by default are
using a realistic memory system.
2014-03-23 11:12:10 -04:00
Wendy Elsasser
bbbae677ed mem: Add close adaptive paging policy to DRAM controller model
This patch adds a second adaptive page policy to the DRAM controller,
closing the page unless there are already queued accesses to the open
page.
2014-03-23 11:12:08 -04:00
Andreas Hansson
03a1aed803 mem: DRAM controller tidying up
Minor tidying up and removing of redundant code, including the
printing of queue state every million accesses.
2014-03-23 11:12:06 -04:00
Andreas Hansson
bc83eb2197 mem: Fix bug in DRAM bytes per activate
This patch ensures that we do not sample the bytes per activate when
the row has already been closed.
2014-03-23 11:12:05 -04:00
Andreas Hansson
116985d661 mem: Limit the accesses to a page before forcing a precharge
This patch adds a basic starvation-prevention mechanism where a DRAM
page is forced to close after a certain number of accesses. The limit
is combined with the open and open-adaptive page policy and if reached
causes an auto-precharge.
2014-03-23 11:12:03 -04:00
Andreas Hansson
6557741311 mem: Make DRAM write queue draining more aggressive
This patch changes the triggering condition for the write draining
such that we grab the opportunity to issue writes if there are no
reads waiting (as opposed to waiting for the writes to reach the high
threshold). As a result, we potentially drain some of the writes in read
idle periods (if any).

A low threshold is added to be able to control how many write bursts
are kept in the memory controller queue (acting as on-chip storage).

The high and low thresholds are updated to sensible values for a 32/64
size write buffer. Note that the thresholds should be adjusted along
with the queue sizes.

This patch also adds some basic initialisation sanity checks and moves
part of the initialisation to the constructor.
2014-03-23 11:12:01 -04:00
Neha Agarwal
43abaf518f mem: DDR3 config for comparing with DRAMSim2
This patch adds a new DDR3 configuration to match with the parameters
that are specified in one of the DDR3 configs used in DRAMSim2.
2014-03-23 11:11:56 -04:00
Andreas Hansson
7e7b67472a mem: More descriptive address-mapping scheme names
This patch adds the row bits to the name of the address mapping
schemes to make it more clear that all the current schemes places the
row bits as the most significant bits.
2014-03-23 11:11:53 -04:00
Andreas Hansson
9ac4f781ec ruby: Move Ruby debug flags to ruby dir and remove stale options
This patch moves the Ruby-related debug flags to the ruby
sub-directory, and also removes the state SConsopts that add the
no-longer-used NO_VECTOR_BOUNDS_CHECK.
2014-03-23 11:11:48 -04:00
Andreas Hansson
9f018d2f5a mem: Include the DRAMSim2 wrapper in NULL build
This patch makes sure DRAMSim2 is included in a build of the NULL ISA.
2014-03-23 11:11:44 -04:00
Sascha Bischoff
548d47ea2c mem: CommMonitor trace warn on non-timing mode
Add a warning to the CommMonitor which will alert the user if they try
and record a trace when the system is not in timing mode.
2014-03-23 11:11:40 -04:00
Nilay Vaish
52a83c1d0e ruby: consumer: avoid accessing wakeup times when waking up
Each consumer object maintains a set of tick values when the object is supposed
to wakeup and do some processing.  As of now, the object accesses this set both
when scheduling a wakeup event and when the object actually wakes up.  The set
is accessed during wakeup to remove the current tick value from the set.  This
functionality is now being moved to the scheduling function where ticks are
removed at a later time.
2014-03-20 09:14:14 -05:00
Nilay Vaish
4b67ada89e ruby: garnet: convert network interfaces into clocked objects
This helps in configuring the network interfaces from the python script and
these objects no longer rely on the network object for the timing information.
2014-03-20 09:14:14 -05:00
Nilay Vaish
4f7ef51efb ruby: slicc: code refactor 2014-03-20 09:14:14 -05:00
Nilay Vaish
9b3418d163 ruby: no piobus in se mode
Piobus was recently added to se scripts for ruby so that the interrupt
controller can be connected to something (required since the interrupt
controller sends address range messages).  This patch removes the piobus
and instead, the pio port of ruby port will now ignore the range change
messages in se mode.
2014-03-20 08:03:09 -05:00
Nilay Vaish
f7e7fa6d90 ruby: remove some of the unnecessary code 2014-03-17 17:40:14 -05:00
Prakash Ramrakhyani
e88cffb30a mem: Fix incorrect assert failure in the Cache
This patch fixes an assert condition that is not true at all
times. There are valid situations that arise in dual-core
dual-workload runs where the assert condition is false. The function
call following the assert however needs to be called only when the
condition is true (a block cannot be invalidated in the tags structure
if has not been allocated in the structure, and the tempBlock is never
allocated). Hence the 'assert' has been replaced with an 'if'.
2014-03-07 15:56:23 -05:00
Ali Saidi
bf39a475fe mem: Wakeup sleeping CPUs without caches on LLSC
For systems without caches, the LLSC code does not get snoops for
wake-ups. We add the LLSC code in the abstract memory to do the job
for us.
2014-03-07 15:56:23 -05:00
Nilay Vaish
5cd9dd29bd ruby: message buffer: changes related to tracking push/pop times
The last pop operation is now tracked as a Tick instead of in Cycles.
This helps in avoiding use of the receiver's clock during the enqueue
operation.
2014-03-01 23:59:58 -06:00
Nilay Vaish
67cd04b6fe ruby: make the max_size variable of the MessageBuffer unsigned 2014-03-01 23:59:57 -06:00
Nilay Vaish
a533f3f983 ruby: profiler: statically allocate stats variable
Couple of users observed segmentation fault when the simulator tries to
register the statistical variable m_IncompleteTimes.  It seems that there
is some problem with the initialization of these variables when allocated
in the constructor.
2014-03-01 23:35:21 -06:00
Nilay Vaish
7e27860ef4 ruby: route all packets through ruby port
Currently, the interrupt controller in x86 is connected to the io bus
directly.  Therefore the packets between the io devices and the interrupt
controller do not go through ruby.  This patch changes ruby port so that
these packets arrive at the ruby port first, which then routes them to their
destination.  Note that the patch does not make these packets go through the
ruby network.  That would happen in a subsequent patch.
2014-02-23 19:16:16 -06:00
Andreas Hansson
5755fff998 ruby: Simplify RubyPort flow control and routing
This patch simplfies the retry logic in the RubyPort, avoiding
redundant attributes, and enforcing more stringent checks on the
interactions with the normal ports. The patch also simplifies the
routing done by the RubyPort, using the port identifiers instead of a
heavy-weight sender state.

The patch also fixes a bug in the sending of responses from PIO
ports. Previously these responses bypassed the queue in the queued
port, and ignored the return value, potentially leading to response
packets being lost.

Committed by: Nilay Vaish <nilay@cs.wisc.edu>
2014-02-23 19:16:16 -06:00
Nilay Vaish
7572ab71b5 ruby: message buffer: refactor code
Code in two of the functions was exactly the same.  This patch moves
this code to a new function which is called from the two functions
mentioned initially.
2014-02-23 19:16:15 -06:00
Nilay Vaish
cde20fd476 ruby: remove few not required #includes 2014-02-23 19:16:15 -06:00
Nilay Vaish
82378f7301 ruby: slicc: remove unused COPY_HEAD functionality 2014-02-23 19:16:15 -06:00
Nilay Vaish
13ad07601b ruby: protocols: remove unused action z_stall 2014-02-23 19:16:15 -06:00
Nilay Vaish
cd33f9bc42 ruby: network: move message buffers to base network class. 2014-02-21 08:02:05 -06:00
Nilay Vaish
bd8f954526 ruby: network: garnet: fixed: removes net_ptr from links 2014-02-21 08:02:04 -06:00
Nilay Vaish
307f53e164 ruby: cache: remove not required variable m_cache_name 2014-02-21 08:02:02 -06:00
Nilay Vaish
f8f8b7e5c2 ruby: network: garnet: fixed: removes next cycle functions
At several places, there are functions that take a cycle value as input
and performs some computation.  Along with each such function, another
function was being defined that simply added one more cycle to input and
computed the same function.  This patch removes this second copy of the
function.  Places where these functions were being called have been updated
to use the original function with argument being current cycle + 1.
2014-02-20 17:28:01 -06:00
Nilay Vaish
896654746a ruby: controller: slight code refactoring 2014-02-20 17:27:45 -06:00
Nilay Vaish
0ce8c25919 ruby: mesi three level: rename incorrectly named files
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
2014-02-20 17:27:17 -06:00
Nilay Vaish
db5b3d37fe ruby: network: removes unused code. 2014-02-20 17:27:07 -06:00
Nilay Vaish
dd5c72e5a7 ruby: slicc: slight code refactoring 2014-02-20 17:26:49 -06:00
Nilay Vaish
b312a41f21 ruby: message buffer: removes some unecessary functions. 2014-02-20 17:26:41 -06:00
Andreas Hansson
4b81585c49 mem: Fix bug in PhysicalMemory use of mmap and munmap
This patch fixes a bug in how physical memory used to be mapped and
unmapped. Previously we unmapped and re-mapped if restoring from a
checkpoint. However, we never checked that the new mapping was
actually the same, it was just magically working as the OS seems to
fairly reliably give us the same chunk back. This patch fixes this
issue by relying entirely on the mmap call in the constructor.
2014-02-18 05:51:01 -05:00
Andreas Hansson
969b436243 mem: Filter cache snoops based on address ranges
This patch adds a filter to the cache to drop snoop requests that are
not for a range covered by the cache. This fixes an issue observed
when multiple caches are placed in parallel, covering different
address ranges. Without this patch, all the caches will forward the
snoop upwards, when only one should do so.
2014-02-18 05:50:58 -05:00
Andreas Hansson
bf2f178f85 mem: Add a wrapped DRAMSim2 memory controller
This patch adds DRAMSim2 as a memory controller by wrapping the
external library and creating a sublass of AbstractMemory that bridges
between the semantics of gem5 and the DRAMSim2 interface.

The DRAMSim2 wrapper extracts the clock period from the config
file. There is no way of extracting this information from DRAMSim2
itself, so we simply read the same config file and get it from there.

To properly model the response queue, the wrapper keeps track of how
many transactions are in the actual controller, and how many are
stacking up waiting to be sent back as responses (in the wrapper). The
latter requires us to move away from the queued port and manage the
packets ourselves. This is due to DRAMSim2 not having any flow control
on the response path.

DRAMSim2 assumes that the transactions it is given are matching the
burst size of the choosen memory. The wrapper checks to ensure the
cache line size of the system matches the burst size of DRAMSim2 as
there are currently no provisions to split the system requests. In
theory we could allow a cache line size smaller than the burst size,
but that would lead to inefficient use of the DRAM, so for not we
fatal also in this case.
2014-02-18 05:50:53 -05:00
Andreas Hansson
c9cb492e1c mem: Fix input to DPRINTF in CommMonitor
Minor fix of the debug message parameters.
2014-02-18 05:50:51 -05:00
Nilay Vaish
bb0e9119e7 ruby: memory controller: use MemoryNode * 2014-02-06 16:30:12 -06:00
Mitch Hayenga
96317d466e mem: Add additional tolerance to stride prefetcher
Forces the prefetcher to mispredict twice in a row before resetting the
confidence of prefetching.  This helps cases where a load PC strides by a
constant factor, however it may operate on different arrays at times.
Avoids the cost of retraining.  Primarily helps with small iteration loops.

Committed by: Nilay Vaish <nilay@cs.wisc.edu>
2014-01-29 23:21:26 -06:00
Mitch Hayenga
771c864bf4 mem: Allowed tagged instruction prefetching in stride prefetcher
For systems with a tightly coupled L2, a stride-based prefetcher may observe
access requests from both instruction and data L1 caches.  However, the PC
address of an instruction miss gives no relevant training information to the
stride based prefetcher(there is no stride to train).  In theses cases, its
better if the L2 stride prefetcher simply reverted back to a simple N-block
ahead prefetcher.  This patch enables this option.

Committed by: Nilay Vaish <nilay@cs.wisc.edu>
2014-01-29 23:21:26 -06:00
Mitch Hayenga ext:(%2C%20Amin%20Farmahini%20%3Caminfar%40gmail.com%3E)
95735e10e7 mem: prefetcher: add options, support for unaligned addresses
This patch extends the classic prefetcher to work on non-block aligned
addresses.  Because the existing prefetchers in gem5 mask off the lower
address bits of cache accesses, many predictable strides fail to be
detected.  For example, if a load were to stride by 48 bytes, with 64 byte
cachelines, the current stride based prefetcher would see an access pattern
of 0, 64, 64, 128, 192.... Thus not detecting a constant stride pattern.  This
patch fixes this, by training the prefetcher on access and not masking off the
lower address bits.

It also adds the following configuration options:
1) Training/prefetching only on cache misses,
2) Training/prefetching only on data acceses,
3) Optionally tagging prefetches with a PC address.
#3 allows prefetchers to train off of prefetch requests in systems with
multiple cache levels and PC-based prefetchers present at multiple levels.
It also effectively allows a pipelining of prefetch requests (like in POWER4)
across multiple levels of cache hierarchy.

Improves performance on my gem5 configuration by 4.3% for SPECINT and 4.7%  for SPECFP (geomean).
2014-01-29 23:21:25 -06:00
Amin Farmahini
ffbdaa7cce mem: Remove redundant findVictim() input argument
The patch
(1) removes the redundant writeback argument from findVictim()
(2) fixes the description of access() function

Committed by: Nilay Vaish <nilay@cs.wisc.edu>
2014-01-28 18:00:50 -06:00
Amin Farmahini
575a73f4a1 mem: Fixes a bug in simple_dram write merging
Fixes updating the value of size in the write merge function.

Committed by: Nilay Vaish <nilay@cs.wisc.edu>
2014-01-28 18:00:49 -06:00
Ali Saidi
90b1775a8f cpu: Add support for instructions that zero cache lines. 2014-01-24 15:29:30 -06:00
Giacomo Gabrielli
d3444c6603 mem: Add flag to request if it was generated by a page table walk 2014-01-24 15:29:30 -06:00