Commit graph

40 commits

Author SHA1 Message Date
Andreas Hansson
92f021cbbe mem: Move the point of coherency to the coherent crossbar
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.
2016-02-10 04:08:25 -05:00
Andreas Hansson
219f1c1a7f configs: Make the default memtest behaviour more complex
Add functional and uncacheable accesses by default.
2015-12-17 17:07:22 -05:00
Andreas Hansson
337774e192 config: Update memtest to stress test clean writebacks
This patch adds yet another twist to the memtest cache hierarchy, in that
the writeback_clean option is toggled at every level to match the
clusivity of the downstream cache.
2015-11-06 03:26:44 -05:00
Andreas Hansson
afa252b0b9 config: Update memtest to stress test cache clusivity
This patch adds an new twist to the memtest cache hierarchy, in that
it switches from mostly inclusive to mostly exclusive at every level
in the tree. This has helped weed out plenty issues, and serves as a
good stress tests.
2015-11-06 03:26:42 -05:00
Andreas Hansson
ddfa96cf45 mem: Add explicit Cache subclass and make BaseCache abstract
Open up for other subclasses to BaseCache and transition to using the
explicit Cache subclass.

--HG--
rename : src/mem/cache/BaseCache.py => src/mem/cache/Cache.py
2015-08-21 07:03:23 -04:00
Andreas Hansson
b93c912013 mem: Remove redundant is_top_level cache parameter
This patch takes the final step in removing the is_top_level parameter
from the cache. With the recent changes to read requests and write
invalidations, the parameter is no longer needed, and consequently
removed.

This also means that asymmetric cache hierarchies are now fully
supported (and we are actually using them already with L1 caches, but
no table-walker caches, connected to a shared L2).
2015-07-03 10:14:43 -04:00
Andreas Hansson
ecd4bad351 config: Add soak test for memtest.py
This patch adds a random option to memtest.py which allows the user to
easily test valid random tree topologies. The patch also adds a
wrapper script to run soak tests using the newly introduced option.

We also adjust the progress interval and progress limit check to make
the output less noisy, and avoid false positives.

Bring on the pain.
2015-03-19 04:06:18 -04:00
Andreas Hansson
36dc93a5fa mem: Move crossbar default latencies to subclasses
This patch introduces a few subclasses to the CoherentXBar and
NoncoherentXBar to distinguish the different uses in the system. We
use the crossbar in a wide range of places: interfacing cores to the
L2, as a system interconnect, connecting I/O and peripherals,
etc. Needless to say, these crossbars have very different performance,
and the clock frequency alone is not enough to distinguish these
scenarios.

Instead of trying to capture every possible case, this patch
introduces dedicated subclasses for the three primary use-cases:
L2XBar, SystemXBar and IOXbar. More can be added if needed, and the
defaults can be overridden.
2015-03-02 04:00:47 -05:00
Andreas Hansson
f18d2120fa config: Add memcheck stress test
This is a rather unfortunate copy of the memtest.py example script,
that actually stresses the system with true sharing as opposed to the
false sharing of the MemTest. To do so it uses TrafficGen instances to
generate the reads/writes, and MemCheckerMonitor combined with the
MemChecker to check the validity of the read/written values.

As a bonus, this script also enables the addition of prefetchers, and
the traffic is created to have a mix of random addresses and linear
strides. We use the TaggedPrefetcher since the packets do not have a
request with a PC.

At the moment the code is almost identical to the memtest.py script,
and no effort has been made to factor out the construction of the
tree. The challenge is that the instantiation and connection of the
testers and monitors is done as part of the tree building.
2015-02-16 03:35:23 -05:00
Andreas Hansson
9738f34411 config: Revamp memtest to allow testers on any level
This patch revamps the memtest example script and allows for the
insertion of testers at any level in the cache hierarchy. Previously
all created topologies placed testers only at the very top, and the
tree was thus entirely symmetric. With the changes made, it is possible
to not only place testers at the leaf caches (L1), but also to connect
testers at the L2, L3 etc.

As part of the changes the object hierarchy is also simplified to
ensure that the visual representation from the DOT printing looks
sensible. Using SubSystems to group the objects is one of the key
features.
2015-02-11 10:23:31 -05:00
Andreas Hansson
6563ec8634 cpu: Tidy up the MemTest and make false sharing more obvious
The MemTest class really only tests false sharing, and as such there
was a lot of old cruft that could be removed. This patch cleans up the
tester, and also makes it more clear what the assumptions are. As part
of this simplification the reference functional memory is also
removed.

The regression configs using MemTest are updated to reflect the
changes, and the stats will be bumped in a separate patch. The example
config will be updated in a separate patch due to more extensive
re-work.

In a follow-on patch a new tester will be introduced that uses the
MemChecker to implement true sharing.
2015-02-11 10:23:28 -05:00
Andreas Hansson
1f6d5f8f84 mem: Rename Bus to XBar to better reflect its behaviour
This patch changes the name of the Bus classes to XBar to better
reflect the actual timing behaviour. The actual instances in the
config scripts are not renamed, and remain as e.g. iobus or membus.

As part of this renaming, the code has also been clean up slightly,
making use of range-based for loops and tidying up some comments. The
only changes outside the bus/crossbar code is due to the delay
variables in the packet.

--HG--
rename : src/mem/Bus.py => src/mem/XBar.py
rename : src/mem/coherent_bus.cc => src/mem/coherent_xbar.cc
rename : src/mem/coherent_bus.hh => src/mem/coherent_xbar.hh
rename : src/mem/noncoherent_bus.cc => src/mem/noncoherent_xbar.cc
rename : src/mem/noncoherent_bus.hh => src/mem/noncoherent_xbar.hh
rename : src/mem/bus.cc => src/mem/xbar.cc
rename : src/mem/bus.hh => src/mem/xbar.hh
2014-09-20 17:18:32 -04:00
Radhika Jagtap
860f00228b config: Fix cache latency param in mem test
This patch fixes the cache latency in mem test which is split into two params,
hit and response latency as per BaseCache.
2014-08-10 05:39:40 -04:00
Ali Saidi
21f1e16763 config: Fix memtest example script 2013-10-17 10:20:45 -05:00
Andreas Hansson
c20105c2ff config: Update script to set cache line size on system
This patch changes the config scripts such that they do not set the
cache line size per cache instance, but rather for the system as a
whole.
2013-07-18 08:31:19 -04:00
Akash Bagdia
7d7ab73862 sim: Add the notion of clock domains to all ClockedObjects
This patch adds the notion of source- and derived-clock domains to the
ClockedObjects. As such, all clock information is moved to the clock
domain, and the ClockedObjects are grouped into domains.

The clock domains are either source domains, with a specific clock
period, or derived domains that have a parent domain and a divider
(potentially chained). For piece of logic that runs at a derived clock
(a ratio of the clock its parent is running at) the necessary derived
clock domain is created from its corresponding parent clock
domain. For now, the derived clock domain only supports a divider,
thus ensuring a lower speed compared to its parent. Multiplier
functionality implies a PLL logic that has not been modelled yet
(create a separate clock instead).

The clock domains should be used as a mechanism to provide a
controllable clock source that affects clock for every clocked object
lying beneath it. The clock of the domain can (in a future patch) be
controlled by a handler responsible for dynamic frequency scaling of
the respective clock domains.

All the config scripts have been retro-fitted with clock domains. For
the System a default SrcClockDomain is created. For CPUs that run at a
different speed than the system, there is a seperate clock domain
created. This domain incorporates the CPU and the associated
caches. As before, Ruby runs under its own clock domain.

The clock period of all domains are pre-computed, such that no virtual
functions or multiplications are needed when calling
clockPeriod. Instead, the clock period is pre-computed when any
changes occur. For this to be possible, each clock domain tracks its
children.
2013-06-27 05:49:49 -04:00
Akash Bagdia
076d04a653 config: Add a system clock command-line option
This patch adds a 'sys_clock' command-line option and use it to assign
clocks to the system during instantiation.

As part of this change, the default clock in the System class is
removed and whenever a system is instantiated a system clock value
must be set. A default value is provided for the command-line option.

The configs and tests are updated accordingly.
2013-06-27 05:49:49 -04:00
Andreas Hansson
6596059d05 Configs: Fix memtest cache latency to match new parameters
This patch changes the memtest config to use the new response latency
of the cache model.
2012-09-27 08:59:25 -04:00
Andreas Hansson
9d9b71e485 Configs: Fix memtest.py by moving the system port
The memtest.py script used to connect the system port directly to the
SimpleMemory, but the latter is now single ported. Since the system
port is not used for anything in this particular example, a quick fix
is to attach it to the functional bus instead.
2012-09-27 03:24:21 -04:00
Andreas Hansson
f00cba34eb Mem: Make SimpleMemory single ported
This patch changes the simple memory to have a single slave port
rather than a vector port. The simple memory makes no attempts at
modelling the contention between multiple ports, and any such
multiplexing and demultiplexing could be done in a bus (or crossbar)
outside the memory controller. This scenario also matches with the
ongoing work on a SimpleDRAM model, which will be a single-ported
single-channel controller that can be used in conjunction with a bus
(or crossbar) to create a multi-port multi-channel controller.

There are only very few regressions that make use of the vector port,
and these are all for functional accesses only. To facilitate these
cases, memtest and memtest-ruby have been updated to also have a
"functional" bus to perform the (de)multiplexing of the functional
memory accesses.
2012-07-12 12:56:13 -04:00
Andreas Hansson
0d32940711 Bus: Split the bus into a non-coherent and coherent bus
This patch introduces a class hierarchy of buses, a non-coherent one,
and a coherent one, splitting the existing bus functionality. By doing
so it also enables further specialisation of the two types of buses.

A non-coherent bus connects a number of non-snooping masters and
slaves, and routes the request and response packets based on the
address. The request packets issued by the master connected to a
non-coherent bus could still snoop in caches attached to a coherent
bus, as is the case with the I/O bus and memory bus in most system
configurations. No snoops will, however, reach any master on the
non-coherent bus itself. The non-coherent bus can be used as a
template for modelling PCI, PCIe, and non-coherent AMBA and OCP buses,
and is typically used for the I/O buses.

A coherent bus connects a number of (potentially) snooping masters and
slaves, and routes the request and response packets based on the
address, and also forwards all requests to the snoopers and deals with
the snoop responses. The coherent bus can be used as a template for
modelling QPI, HyperTransport, ACE and coherent OCP buses, and is
typically used for the L1-to-L2 buses and as the main system
interconnect.

The configuration scripts are updated to use a NoncoherentBus for all
peripheral and I/O buses.

A bit of minor tidying up has also been done.

--HG--
rename : src/mem/bus.cc => src/mem/coherent_bus.cc
rename : src/mem/bus.hh => src/mem/coherent_bus.hh
rename : src/mem/bus.cc => src/mem/noncoherent_bus.cc
rename : src/mem/bus.hh => src/mem/noncoherent_bus.hh
2012-05-31 13:30:04 -04:00
Andreas Hansson
b00949d88b MEM: Enable multiple distributed generalized memories
This patch removes the assumption on having on single instance of
PhysicalMemory, and enables a distributed memory where the individual
memories in the system are each responsible for a single contiguous
address range.

All memories inherit from an AbstractMemory that encompasses the basic
behaviuor of a random access memory, and provides untimed access
methods. What was previously called PhysicalMemory is now
SimpleMemory, and a subclass of AbstractMemory. All future types of
memory controllers should inherit from AbstractMemory.

To enable e.g. the atomic CPU and RubyPort to access the now
distributed memory, the system has a wrapper class, called
PhysicalMemory that is aware of all the memories in the system and
their associated address ranges. This class thus acts as an
infinitely-fast bus and performs address decoding for these "shortcut"
accesses. Each memory can specify that it should not be part of the
global address map (used e.g. by the functional memories by some
testers). Moreover, each memory can be configured to be reported to
the OS configuration table, useful for populating ATAG structures, and
any potential ACPI tables.

Checkpointing support currently assumes that all memories have the
same size and organisation when creating and resuming from the
checkpoint. A future patch will enable a more flexible
re-organisation.

--HG--
rename : src/mem/PhysicalMemory.py => src/mem/AbstractMemory.py
rename : src/mem/PhysicalMemory.py => src/mem/SimpleMemory.py
rename : src/mem/physical.cc => src/mem/abstract_mem.cc
rename : src/mem/physical.hh => src/mem/abstract_mem.hh
rename : src/mem/physical.cc => src/mem/simple_mem.cc
rename : src/mem/physical.hh => src/mem/simple_mem.hh
2012-04-06 13:46:31 -04:00
Andreas Hansson
6cf9f182f6 MEM: Fix residual bus ports and make them master/slave
This patch cleans up a number of remaining uses of bus.port which
is now split into bus.master and bus.slave. The only non-trivial change
is the memtest where the level building now has to be aware of the role
of the ports used in the previous level.
2012-02-14 14:15:30 -05:00
Gabe Black
ec20ee2f7c SE/FS: Make SE vs. FS mode a runtime parameter. 2012-01-28 07:24:34 -08:00
Steve Reinhardt
6d9fc4175e memtest: scale associativity and mshrs according to config
Use the actual fanouts in the tree specification to scale
cache associativity and mshrs instead of dumb constants.
2010-08-25 21:55:42 -07:00
Steve Reinhardt
1fbe466345 sim: make Python Root object a singleton
Enforce that the Python Root SimObject is instantiated only
once.  The C++ Root object already panics if more than one is
created.  This change avoids the need to track what the root
object is, since it's available from Root.getInstance() (if it
exists).  It's now redundant to have the user pass the root
object to functions like instantiate(), checkpoint(), and
restoreCheckpoint(), so that arg is gone.  Users who use
configs/common/Simulate.py should not notice.
2010-08-17 05:06:22 -07:00
Nathan Binkert
9a8cb7db7e python: Move more code into m5.util allow SCons to use that code.
Get rid of misc.py and just stick misc things in __init__.py
Move utility functions out of SCons files and into m5.util
Move utility type stuff from m5/__init__.py to m5/util/__init__.py
Remove buildEnv from m5 and allow access only from m5.defines
Rename AddToPath to addToPath while we're moving it to m5.util
Rename read_command to readCommand while we're moving it
Rename compare_versions to compareVersions while we're moving it.

--HG--
rename : src/python/m5/convert.py => src/python/m5/util/convert.py
rename : src/python/m5/smartdict.py => src/python/m5/util/smartdict.py
2009-09-22 15:24:16 -07:00
Steve Reinhardt
884807a68a Fix up a bunch of multilevel coherence issues.
Atomic mode seems to work.  Timing is closer but not there yet.

--HG--
extra : convert_revision : 0dea5c3d4b973d009e9d4a4c21b9cad15961d56f
2007-07-15 20:11:06 -07:00
Steve Reinhardt
9172876dd7 Fix problem with unset max_loads in memtest.
Also make default 0, and make that mean run forever.

--HG--
extra : convert_revision : 3e60a52b1c5e334a9ef3d744cf7ee1d851ba4aa9
2007-07-15 14:32:55 -07:00
Steve Reinhardt
b1bdc3b3d9 Punt on old -n/-c memtest args.
Also added comments to document treespec format.

--HG--
extra : convert_revision : fa9e8f66b68b96a4efca8a7fe6e7c37367382d9d
2007-07-15 14:07:31 -07:00
Steve Reinhardt
ad560a6642 Add --force-bus option to memtest.py.
--HG--
extra : convert_revision : 101735cca426903704ff2edaff051fa7c5bfc46c
2007-07-15 13:22:49 -07:00
Steve Reinhardt
4bcfa916f1 New tree-based algorithm for creating more complex cache hierarchies.
--HG--
extra : convert_revision : de8dd4ef5dae0f3e084461e8ef7c549653e61d3f
2007-07-14 23:49:24 -07:00
Steve Reinhardt
9117c94f9c Get rid of coherence protocol object.
--HG--
extra : convert_revision : 4ff144342dca23af9a12a2169ca318a002654b42
2007-06-27 20:54:13 -07:00
Steve Reinhardt
83af0fdcf5 Getting closer...
configs/example/memtest.py:
    Add progress interval option.
src/base/traceflags.py:
    Add MemTest flag.
src/cpu/memtest/memtest.cc:
    Clean up tracing.
src/cpu/memtest/memtest.hh:
    Get rid of unused code.

--HG--
extra : convert_revision : 92bd8241a6c90bfb6d908e5a5132cbdb500cbb87
2007-06-21 11:59:17 -07:00
Steve Reinhardt
35cf19d441 More major reorg of cache. Seems to work for atomic mode now,
timing mode still broken.

configs/example/memtest.py:
    Revamp options.
src/cpu/memtest/memtest.cc:
    No need for memory initialization.
    No need to make atomic response... memory system should do that now.
src/cpu/memtest/memtest.hh:
    MemTest really doesn't want to snoop.
src/mem/bridge.cc:
    checkFunctional() cleanup.
src/mem/bus.cc:
src/mem/bus.hh:
src/mem/cache/base_cache.cc:
src/mem/cache/base_cache.hh:
src/mem/cache/cache.cc:
src/mem/cache/cache.hh:
src/mem/cache/cache_blk.hh:
src/mem/cache/cache_builder.cc:
src/mem/cache/cache_impl.hh:
src/mem/cache/coherence/coherence_protocol.cc:
src/mem/cache/coherence/coherence_protocol.hh:
src/mem/cache/coherence/simple_coherence.hh:
src/mem/cache/miss/SConscript:
src/mem/cache/miss/mshr.cc:
src/mem/cache/miss/mshr.hh:
src/mem/cache/miss/mshr_queue.cc:
src/mem/cache/miss/mshr_queue.hh:
src/mem/cache/prefetch/base_prefetcher.cc:
src/mem/cache/tags/fa_lru.cc:
src/mem/cache/tags/fa_lru.hh:
src/mem/cache/tags/iic.cc:
src/mem/cache/tags/iic.hh:
src/mem/cache/tags/lru.cc:
src/mem/cache/tags/lru.hh:
src/mem/cache/tags/split.cc:
src/mem/cache/tags/split.hh:
src/mem/cache/tags/split_lifo.cc:
src/mem/cache/tags/split_lifo.hh:
src/mem/cache/tags/split_lru.cc:
src/mem/cache/tags/split_lru.hh:
src/mem/packet.cc:
src/mem/packet.hh:
src/mem/physical.cc:
src/mem/physical.hh:
src/mem/tport.cc:
    More major reorg.  Seems to work for atomic mode now,
    timing mode still broken.

--HG--
extra : convert_revision : 7e70dfc4a752393b911880ff028271433855ae87
2007-06-17 17:27:53 -07:00
Steve Reinhardt
9f1c104ccd memtest.py:
Make clocks more reasonable.
Fix bug in sense of options.timing flag.

configs/example/memtest.py:
    Fix bug in sense of options.timing flag.
configs/example/memtest.py:
    Make clocks more reasonable.

--HG--
extra : convert_revision : 3715697988c56e92a4da129b42026d0623f5e85e
2007-05-22 06:22:27 -07:00
Steve Reinhardt
0305159abf PhysicalMemory has vector of uniform ports instead of one special one.
configs/example/memtest.py:
    PhysicalMemory has vector of uniform ports instead of one special one.
    Other updates to fix obsolete brokenness.
src/mem/physical.cc:
src/mem/physical.hh:
src/python/m5/objects/PhysicalMemory.py:
    Have vector of uniform ports instead of one special one.
src/python/swig/pyobject.cc:
    Add comment.

--HG--
extra : convert_revision : a4a764dcdcd9720bcd07c979d0ece311fc8cb4f1
2007-05-19 00:24:34 -04:00
Ron Dreslinski
6098f57b08 Update for maxtick in splash2/memtest configs
configs/example/memtest.py:
configs/splash2/run.py:
    Update for maxtick

--HG--
extra : convert_revision : 94106625be1ebc2b614db16720a4861e47222c0b
2006-11-12 11:42:07 -05:00
Ron Dreslinski
ad783962c5 Give physical memory some latency to stress the system
--HG--
extra : convert_revision : 3ca32ff9140770d0774cac5e82807a0574db09dd
2006-10-20 13:36:26 -04:00
Ron Dreslinski
316e0fa879 Add a config file in the example with the memtester and some parser options.
--HG--
extra : convert_revision : e70ccc3de4f7a3ae20ff9ec672853ee1555ed41b
2006-10-20 13:32:24 -04:00