Commit graph

23 commits

Author SHA1 Message Date
Brad Beckmann
f5aa75fdc5 ruby: support to stallAndWait the mandatory queue
By stalling and waiting the mandatory queue instead of recycling it, one can
ensure that no incoming messages are starved when the mandatory queue puts
signficant of pressure on the L1 cache controller (i.e. the ruby memtester).

--HG--
rename : src/mem/slicc/ast/WakeUpDependentsStatementAST.py => src/mem/slicc/ast/WakeUpAllDependentsStatementAST.py
2011-02-06 22:14:19 -08:00
Brad Beckmann
1b54344aeb MOESI_hammer: Added full-bit directory support 2011-02-06 22:14:18 -08:00
Joel Hestness
02b05bf9be MOESI_hammer: trigge queue fix. 2011-02-06 22:14:17 -08:00
Nilay Vaish
c82a8979a3 Change interface between coherence protocols and CacheMemory
The purpose of this patch is to change the way CacheMemory interfaces with
coherence protocols. Currently, whenever a cache controller (defined in the
protocol under consideration) needs to carry out any operation on a cache
block, it looks up the tag hash map and figures out whether or not the block
exists in the cache. In case it does exist, the operation is carried out
(which requires another lookup). As observed through profiling of different
protocols, multiple such lookups take place for a given cache block. It was
noted that the tag lookup takes anything from 10% to 20% of the simulation
time. In order to reduce this time, this patch is being posted.

I have to acknowledge that the many of the thoughts that went in to this
patch belong to Brad.

Changes to CacheMemory, TBETable and AbstractCacheEntry classes:
1. The lookup function belonging to CacheMemory class now returns a pointer
to a cache block entry, instead of a reference. The pointer is NULL in case
the block being looked up is not present in the cache. Similar change has
been carried out in the lookup function of the TBETable class.
2. Function for setting and getting access permission of a cache block have
been moved from CacheMemory class to AbstractCacheEntry class.
3. The allocate function in CacheMemory class now returns pointer to the
allocated cache entry.

Changes to SLICC:
1. Each action now has implicit variables - cache_entry and tbe. cache_entry,
if != NULL, must point to the cache entry for the address on which the action
is being carried out. Similarly, tbe should also point to the transaction
buffer entry of the address on which the action is being carried out.
2. If a cache entry or a transaction buffer entry is passed on as an
argument to a function, it is presumed that a pointer is being passed on.
3. The cache entry and the tbe pointers received __implicitly__ by the
actions, are passed __explicitly__ to the trigger function.
4. While performing an action, set/unset_cache_entry, set/unset_tbe are to
be used for setting / unsetting cache entry and tbe pointers respectively.
5. is_valid() and is_invalid() has been made available for testing whether
a given pointer 'is not NULL' and 'is NULL' respectively.
6. Local variables are now available, but they are assumed to be pointers
always.
7. It is now possible for an object of the derieved class to make calls to
a function defined in the interface.
8. An OOD token has been introduced in SLICC. It is same as the NULL token
used in C/C++. If you are wondering, OOD stands for Out Of Domain.
9. static_cast can now taken an optional parameter that asks for casting the
given variable to a pointer of the given type.
10. Functions can be annotated with 'return_by_pointer=yes' to return a
pointer.
11. StateMachine has two new variables, EntryType and TBEType. EntryType is
set to the type which inherits from 'AbstractCacheEntry'. There can only be
one such type in the machine. TBEType is set to the type for which 'TBE' is
used as the name.

All the protocols have been modified to conform with the new interface.
2011-01-17 18:46:16 -06:00
Nilay Vaish
d36cc62c11 Ruby: Updates MOESI Hammer protocol
This patch changes the manner in which data is copied from L1 to L2 cache in
the implementation of the Hammer's cache coherence protocol. Earlier, data was
copied directly from one cache entry to another. This has been broken in to
two parts. First, the data is copied from the source cache entry to a
transaction buffer entry. Then, data is copied from the transaction buffer
entry to the destination cache entry.

This has been done to maintain the invariant - at any given instant, multiple
caches under a controller are exclusive with respect to each other.
2011-01-04 21:40:49 -06:00
Nilay Vaish
658849d101 ruby: Converted old ruby debug calls to M5 debug calls
This patch developed by Nilay Vaish converts all the old GEMS-style ruby
debug calls to the appropriate M5 debug calls.
2010-12-01 11:30:04 -08:00
Brad Beckmann
20b2f0ce9f MOESI_hammer: fixed bug for dma reads in single cpu systems 2010-08-24 12:06:53 -07:00
Brad Beckmann
8557480300 ruby: Added merge GETS optimization to hammer
Added an optimization that merges multiple pending GETS requests into a
single request to the owner node.
2010-08-20 11:46:14 -07:00
Brad Beckmann
f57053473a MOESI_hammer: break down miss latency stalled cycles
This patch tracks the number of cycles a transaction is delayed at different
points of the request-forward-response loop.
2010-08-20 11:46:14 -07:00
Brad Beckmann
8b28848321 ruby: added probe filter support to hammer 2010-08-20 11:46:14 -07:00
Brad Beckmann
72044e3f5a ruby: Disable migratory sharing for token and hammer
This patch allows one to disable migratory sharing for those cache blocks that
are accessed by atomic requests.  While the implementations are different
between the token and hammer protocols, the motivation is the same.  For
Alpha, LLSC semantics expect that normal loads do not unlock cache blocks that
have been locked by LL accesses.  Therefore, locked blocks should not transfer
write permissions when responding to these load requests.  Instead, only they
only transfer read permissions so that the subsequent SC access can possibly
succeed.
2010-08-20 11:46:13 -07:00
Brad Beckmann
984adf198a ruby: Updated MOESI_hammer L2 latency behavior
Previously, the MOESI_hammer protocol calculated the same latency for L1 and
L2 hits.  This was because the protocol was written using the old ruby
assumption that L1 hits used the sequencer fast path.  Since ruby no longer
uses the fast-path, the protocol delays L2 hits by placing them on the
trigger queue.
2010-08-20 11:46:13 -07:00
Brad Beckmann
29c45ccd23 ruby: Reduced ruby latencies
The previous slower ruby latencies created a mismatch between the faster M5
cpu models and the much slower ruby memory system.  Specifically smp
interrupts were much slower and infrequent, as well as cpus moving in and out
of spin locks.  The result was many cpus were idle for large periods of time.

These changes fix the latency mismatch.
2010-08-20 11:46:12 -07:00
Brad Beckmann
4b4e725921 ruby: Reincarnated the responding machine profiling
This patch adds back to ruby the capability to understand the response time
for messages that hit in different levels of the cache heirarchy.
Specifically add support for the MI_example, MOESI_hammer, and MOESI_CMP_token
protocols.
2010-08-20 11:46:12 -07:00
Brad Beckmann
61f1d9a3d7 ruby: Reordered protocol buffers
Reordered vnet priorities to agree with PerfectSwitch for protocols MI_example,
MOESI_CMP_token, and MOESI_hammer
2010-03-21 21:22:21 -07:00
Brad Beckmann
c48a735336 ruby: Fix MOESI_hammer cache profiler calls for L2 misses 2010-03-21 21:22:20 -07:00
Brad Beckmann
143d8ea698 ruby: removed last level cache support
Removed the last level cache support and MOESI_hammer's dependency on it.
Replaces the LLC support with the more generic MachineType count.
2010-01-29 20:29:34 -08:00
Brad Beckmann
66279fac3f ruby: Added atomic support to MOESI_hammer 2010-01-29 20:29:23 -08:00
Brad Beckmann
ed81489954 ruby: Ruby changes required to use the python config system
This patch includes the necessary changes to connect ruby objects using
the python configuration system.  Mainly it consists of removing
unnecessary ruby object pointers and connecting the necessary object
pointers using the generated param objects.  This patch includes the
slicc changes necessary to connect generated ruby objects together using
the python configuraiton system.
2010-01-29 20:29:19 -08:00
Steve Reinhardt
c6f1d959be ruby: Make SLICC-generated objects SimObjects.
Also add SLICC support for state-machine parameter defaults
(passed through to Python as SimObject Param defaults).
2010-01-29 20:29:17 -08:00
Brad Beckmann
bc12b8432d ruby: Hammer ruby configuration support 2009-11-18 16:34:32 -08:00
Brad Beckmann
877be2009c ruby: Changes necessary to get the hammer protocol to work in GEM5 2009-11-18 16:34:32 -08:00
Brad Beckmann
b0973035b4 ruby: added the original hammer protocols from old ruby 2009-11-18 16:34:31 -08:00