Commit graph

1266 commits

Author SHA1 Message Date
Andreas Hansson
f6550b3d20 mem: Tighten up cache constness and scoping
This patch merely adopts a more strict use of const for the cache
member functions and variables, and also moves a large portion of the
member functions from public to protected.
2013-02-15 17:40:10 -05:00
Andreas Sandberg
b904bd5437 sim: Add a system-global option to bypass caches
Virtualized CPUs and the fastmem mode of the atomic CPU require direct
access to physical memory. We currently require caches to be disabled
when using them to prevent chaos. This is not ideal when switching
between hardware virutalized CPUs and other CPU models as it would
require a configuration change on each switch. This changeset
introduces a new version of the atomic memory mode,
'atomic_noncaching', where memory accesses are inserted into the
memory system as atomic accesses, but bypass caches.

To make memory mode tests cleaner, the following methods are added to
the System class:

 * isAtomicMode() -- True if the memory mode is 'atomic' or 'direct'.
 * isTimingMode() -- True if the memory mode is 'timing'.
 * bypassCaches() -- True if caches should be bypassed.

The old getMemoryMode() and setMemoryMode() methods should never be
used from the C++ world anymore.
2013-02-15 17:40:09 -05:00
Andreas Hansson
7c6bc52bf5 Ruby: Fix compilation errors on gcc 4.7 and clang 3.2
This patch fixes a few (recently added) errors that prevented gem5 from
compiling on more recent versions of gcc and clang.
2013-02-14 12:24:51 -05:00
Nilay Vaish
71c27e6370 ruby: MI protocol: add a missing transition
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
2013-02-10 21:43:18 -06:00
Nilay Vaish
cb7782f78d ruby: enable multiple clock domains
This patch allows ruby to have multiple clock domains. As I understand
with this patch, controllers can have different frequencies. The entire
network needs to run at a single frequency.

The idea is that with in an object, time is treated in terms of cycles.
But the messages that are passed from one entity to another should contain
the time in Ticks. As of now, this is only true for the message buffers,
but not for the links in the network. As I understand the code, all the
entities in different networks (simple, garnet-fixed, garnet-flexible) should
be clocked at the same frequency.

Another problem is that the directory controller has to operate at the same
frequency as the ruby system. This is because the memory controller does
not make use of the Message Buffer, and instead implements a buffer of its
own. So, it has no idea of the frequency at which the directory controller
is operating and uses ruby system's frequency for scheduling events.
2013-02-10 21:43:17 -06:00
Nilay Vaish
253e8edf13 ruby: replace Time with Cycles (final patch in the series)
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.
2013-02-10 21:43:10 -06:00
Nilay Vaish
f6e3ab7bd4 ruby: replace Time with Cycles in garnet fixed and flexible 2013-02-10 21:43:09 -06:00
Nilay Vaish
9d6d6c6718 ruby: replace Time with Tick in replacement policy classes 2013-02-10 21:43:08 -06:00
Nilay Vaish
221d39284e ruby: convert block size, memory size to unsigned 2013-02-10 21:43:07 -06:00
Nilay Vaish
5e33045a2a ruby: replace Time with Cycles in MessageBuffer 2013-02-10 21:26:26 -06:00
Nilay Vaish
b742081cc1 ruby: replace Time with Cycles in Memory Controller 2013-02-10 21:26:25 -06:00
Nilay Vaish
89f86dbd28 ruby: Replace Time with Cycles in SequencerMessage 2013-02-10 21:26:25 -06:00
Nilay Vaish
7862478eef ruby: replace Time with Cycles in Message class
Concomitant changes are being committed as well, including the io operator<<
for the Cycles class.
2013-02-10 21:26:24 -06:00
Nilay Vaish
d3aebe1f91 ruby: replaces Time with Cycles in many places
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.
2013-02-10 21:26:24 -06:00
Nilay Vaish
bc1daae7fd ruby: modifies histogram add() function
This patch modifies the Histogram class' add() function so that it can add
linear histograms as well. The function assumes that the left end point of
the ranges of the two histograms are the same. It also assumes that when
the ranges of the two histogram are changed to accomodate an element not in
the range, the factor used in changing the range is same for both the
histograms.

This function is then used in removing one of the calls to the global
profiler*. The histograms for recording the delays incurred in processing
different requests are now maintained by the controllers. The profiler
adds these histograms when it needs to print the stats.
2013-02-10 21:26:22 -06:00
Nilay Vaish
a49b1df3f0 ruby: record fully busy cycle with in the controller
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.
2013-02-10 21:26:22 -06:00
Nilay Vaish
6aed4d4f93 ruby: correct computation of number of bits required for address
The number of bits required for an address was set to floorLog2(memory size).
This is correct under the assumption that the memory size is a power of 2,
which is not always true. Hence, floorLog2 is being replaced with ceilLog2.
2013-01-31 09:44:20 -06:00
Andreas Hansson
a4288dabf9 mem: Add comments for the DRAM address decoding
This patch adds more verbose comments to explain the two different
address mapping schemes of the DRAM controller.
2013-01-31 07:49:18 -05:00
Andreas Hansson
c4898b15bc mem: Add DDR3 and LPDDR2 DRAM controller configurations
This patch moves the default DRAM parameters from the SimpleDRAM class
to two different subclasses, one for DDR3 and one for LPDDR2. More can
be added as we go forward.

The regressions that previously used the SimpleDRAM are now using
SimpleDDR3 as this is the most similar configuration.
2013-01-31 07:49:14 -05:00
Ani Udipi
eaa37e611f mem: Add tTAW and tFAW to the SimpleDRAM model
This patch adds two additional scheduling constraints to the DRAM
controller model, to constrain the activation rate. The two metrics
are determine the size of the activation window in terms of the number
of activates and the minimum time required for that number of
activates. This maps to current DDRx, LPDDRx and WIOx standards that
have either tFAW (4 activate window) or tTAW (2 activate window)
scheduling constraints.
2013-01-31 07:49:14 -05:00
Andreas Hansson
b7153e2a64 mem: Separate out the different cases for DRAM bus busy time
This patch changes how the data bus busy time is calculated such that
it is delayed to the actual scheduling time of the request as opposed
to being done as soon as possible.

This patch changes a bunch of statistics, and the stats update is
bundled together with the introruction of tFAW/tTAW and the named DRAM
configurations like DDR3 and LPDDR2.
2013-01-31 07:49:13 -05:00
Anthony Gutierrez
af0f8b31db cache: remove drainManager because it's not used
the cache drainManager is set but never cleared, this is because
the cache itself does not need to be drained and thus never
triggers a signalDrainDone(). because the drainManager variable
is not used properly and does not appear to be necessary it has
been removed with this patch.
2013-01-28 20:19:42 -05:00
Nilay Vaish
a8eb5b18e0 ruby: remove get_time()
This patch replaces get_time() in *.sm files with curCycle() which
is now possible since controllers are clocked objects.
2013-01-28 06:14:18 -06:00
Nilay Vaish
31659e83fb ruby: remove call to curCycle in panic()
The panic() function already prints the current tick value. This call to
curCycle() is as such redundant. Since we are trying to move towards multiple
clock domains, this call will print misleading time.
2013-01-28 06:11:42 -06:00
Nilay Vaish
5b6f972750 ruby: remove calls to g_system_ptr->getTime()
This patch further removes calls to g_system_ptr->getTime() where ever other
clocked objects are available for providing current time.
2013-01-17 13:10:12 -06:00
Malek Musleh
1abf950f3c ruby sequencer: converts cycles to ticks in deadlock panic()
This patch converts the panic() print outs in the Sequencer::wakeup()
call from ruby cycles to Ticks(). This makes it easier to debug deadlocks
with the ProtocolTrace flag so the issue time indicated in the panic message
can be quickly searched for.

Committed by: Nilay Vaish <nilay@cs.wisc.edu>
2013-01-14 10:05:12 -06:00
Nilay Vaish
2012983718 Ruby: remove reference to g_system_ptr from class Message
This patch was initiated so as to remove reference to g_system_ptr,
the pointer to Ruby System that is used for getting the current time.
That simple change actual requires changing a lot many things in slicc and
garnet. All these changes are related to how time is handled.

In most of the places, g_system_ptr has been replaced by another clock
object. The changes have been done under the assumption that all the
components in the memory system are on the same clock frequency, but the
actual clocks might be distributed.
2013-01-14 10:05:10 -06:00
Nilay Vaish
cf232de461 Ruby: use ClockedObject in Consumer class
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.
2013-01-14 10:04:21 -06:00
Mitch Hayenga
c7dbd5e768 mem: Make LL/SC locks fine grained
The current implementation in gem5 just keeps a list of locks per cacheline.
Due to this, a store to a non-overlapping portion of the cacheline can cause an
LL/SC pair to fail.  This patch simply adds an address range to the lock
structure, so that the lock is only invalidated if the store overlaps the lock
range.
2013-01-08 08:54:07 -05:00
Mitch Hayenga
dc4a0aa2fa mem: Fix use-after-free bug
Running with valgrind I noticed a use after free originating from
simple_mem.cc.  It looks like this is a known issue and this additional call
site was missed in an earlier patch.
2013-01-08 08:54:06 -05:00
Andreas Sandberg
964aa49d15 mem: Fix guest corruption when caches handle uncacheable accesses
When the classic gem5 cache sees an uncacheable memory access, it used
to ignore it or silently drop the cache line in case of a
write. Normally, there shouldn't be any data in the cache belonging to
an uncacheable address range. However, since some architecture models
don't implement cache maintenance instructions, there might be some
dirty data in the cache that is discarded when this happens. The
reason it has mostly worked before is because such cache lines were
most likely evicted by normal memory activity before a TLB flush was
requested by the OS.

Previously, the cache model would invalidate cache lines when they
were accessed by an uncacheable write. This changeset alters this
behavior so all uncacheable memory accesses cause a cache flush with
an associated writeback if necessary. This is implemented by reusing
the cache flushing machinery used when draining the cache, which
implies that writebacks are performed using functional accesses.
2013-01-07 13:05:47 -05:00
Andreas Sandberg
d44f2f611f mem: Remove the IIC replacement policy
The IIC replacement policy seems to be unused and has probably
gathered too much bit rot to be useful. This patch removes the IIC and
its associated cache parameters.
2013-01-07 13:05:39 -05:00
Andreas Hansson
921490a060 sim: Fatal if a clocked object is set to have a clock of 0
This patch adds a check to the clocked object constructor to ensure it
is not configured to have a clock period of 0.
2013-01-07 13:05:39 -05:00
Andreas Hansson
18b147acef mem: Merge ranges that are part of the conf table
This patch adds basic merging of address ranges when determining which
address ranges should be reported in the configuration table. By
performing this merging it is possible to distribute an address range
across many memory channels (controllers). This is essential to enable
address interleaving.
2013-01-07 13:05:38 -05:00
Andreas Hansson
01c5598373 mem: Add interleaving bits to the address ranges
This patch adds support for interleaving bits for the address
ranges. What was previously just a start and end address, now has an
additional three fields, for the high bit, and number of bits to use
for interleaving, and a match value to compare against. If the number
of interleaving bits is set to zero it is effectively disabled.

A number of convenience functions are added to the range to enquire
about the interleaving, its granularity and the number of stripes it
is part of.
2013-01-07 13:05:38 -05:00
Andreas Hansson
e0d93fde99 base: Simplify the AddrRangeMap by removing unused code
This patch cleans up the AddrRangeMap in preparation for the addition
of interleaving by removing unused code. The non-const editions of
find are never used, and hence the duplication is not needed.
2013-01-07 13:05:38 -05:00
Andreas Hansson
15a979c6be mem: Tidy up bus addr range debug messages
This patch tidies up a number of the bus DPRINTFs related to range
manipulation. In particular, it shifts the message about range changes
to the start of the member function, and also adds information about
when all ranges are received.
2013-01-07 13:05:38 -05:00
Andreas Hansson
caf6786ad5 mem: Skip address mapper range checks to allow more flexibility
This patch makes the address mapper less stringent about checking the
before and after ranges, i.e. the original and remapped ranges. The
checks were not really necessary, and there are situations when the
previous checks were too strict.
2013-01-07 13:05:38 -05:00
Andreas Hansson
71da1d2157 base: Encapsulate the underlying fields in AddrRange
This patch makes the start and end address private in a move to
prevent direct manipulation and matching of ranges based on these
fields. This is done so that a transition to ranges with interleaving
support is possible.

As a result of hiding the start and end, a number of member functions
are needed to perform the comparisons and manipulations that
previously took place directly on the members. An accessor function is
provided for the start address, and a function is added to test if an
address is within a range. As a result of the latter the != and ==
operator is also removed in favour of the member function. A member
function that returns a string representation is also created to allow
debug printing.

In general, this patch does not add any functionality, but it does
take us closer to a situation where interleaving (and more cleverness)
can be added under the bonnet without exposing it to the user. More on
that in a later patch.
2013-01-07 13:05:38 -05:00
Andreas Hansson
cfdaf53104 mem: Remove the joining of neighbouring ranges
This patch temporarily removes the joining of ranges when creating the
backing store, to reserve this functionality for the interleaved
ranges that are about to be introduced.

When creating the mmaps for the backing store, there is no point in
creating larger contigous chunks that what is necessary. The larger
chunks will only make life more difficult for the host.

Merging will be re-added later, but then only for interleaved ranges.
2013-01-07 13:05:38 -05:00
Andreas Hansson
f456c7983d mem: Add tracing support in the communication monitor
This patch adds packet tracing to the communication monitor using a
protobuf as the mechanism for creating the trace.

If no file is specified, then the tracing is disabled. If a file is
specified, then for every packet that is successfully sent, a protobuf
message is serialized to the file.
2013-01-07 13:05:37 -05:00
Andreas Hansson
852a7bcf92 mem: Add sanity check to packet queue size
This patch adds a basic check to ensure that the packet queue does not
grow absurdly large. The queue should only be used to store packets
that were delayed due to blocking from the neighbouring port, and not
for actual storage. Thus, a limit of 100 has been chosen for now
(which is already quite substantial).
2013-01-07 13:05:35 -05:00
Andreas Hansson
ce5fc494e3 ruby: Fix missing cxx_header in Switch
This patch addresses a warning related to the swig interface
generation for the Switch class. The cxx_header is now specified
correctly, and the header in question has got a few includes added to
make it all compile.
2013-01-07 13:05:35 -05:00
Andreas Hansson
174269978a mem: Fix a bug in the memory serialization file naming
This patch fixes a bug that caused multiple systems to overwrite each
other physical memory. The system name is now included in the filename
such that this is avoided.
2013-01-07 13:05:35 -05:00
Ali Saidi
9a645d6e9b cache: add note about where conflicts are handled 2013-01-07 13:05:32 -05:00
Nilay Vaish
f3d0be210f ruby: add support for prefetching to MESI protocol 2012-12-11 10:05:56 -06:00
Nilay Vaish
9b72a0f627 ruby: change slicc to allow for constructor args
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.
2012-12-11 10:05:55 -06:00
Nilay Vaish
93e283abb3 ruby: add a prefetcher
This patch adds a prefetcher for the ruby memory system. The prefetcher
is based on a prefetcher implemented by others (well, I don't know
who wrote the original). The prefetcher does stride-based prefetching,
both unit and non-unit. It obseves the misses in the cache and trains on
these. After the training period is over, the prefetcher starts issuing
prefetch requests to the controller.
2012-12-11 10:05:54 -06:00
Nilay Vaish
d502384795 ruby: add functions for computing next stride/page address 2012-12-11 10:05:53 -06:00
Nilay Vaish
2d6470936c sim: have a curTick per eventq
This patch adds a _curTick variable to an eventq. This variable is updated
whenever an event is serviced in function serviceOne(), or all events upto
a particular time are processed in function serviceEvents(). This change
helps when there are eventqs that do not make use of curTick for scheduling
events.
2012-11-16 10:27:47 -06:00