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.
This patch fixes several bugs related to previous inconsistent assumptions on
how many tokens the Owner had. Mike Marty should have fixes these bugs years
ago. :)
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.
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.
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.
In addition to obvious changes, this required a slight change to the slicc
grammar to allow types with :: in them. Otherwise slicc barfs on std::string
which we need for the headers that slicc generates.
This patch includes the necessary regression updates to test the new ruby
configuration system. The patch includes support for multiple ruby protocols
and adds the ruby random tester. The patch removes atomic mode test for
ruby since ruby does not support atomic mode acceses. These tests can be
added back in when ruby supports atomic mode for real.
--HG--
rename : tests/quick/50.memtest/test.py => tests/quick/60.rubytest/test.py
Renamed the MESI directory file to be consistent with all other protocols.
--HG--
rename : src/mem/protocol/MESI_CMP_directory-mem.sm => src/mem/protocol/MESI_CMP_directory-dir.sm
Reorganized ruby python configuration so that protocol and ruby memory system
configuration code can be shared by multiple front-end configuration files
(i.e. memory tester, full system, and hopefully the regression tester). This
code works for memory tester, but have not tested fs mode.
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.
This patch changes the way that Ruby handles atomic RMW instructions. This implementation, unlike the prior one, is protocol independent. It works by locking an address from the sequencer immediately after the read portion of an RMW completes. When that address is locked, the coherence controller will only satisfy requests coming from one port (e.g., the mandatory queue) and will ignore all others. After the write portion completed, the line is unlocked. This should also work with multi-line atomics, as long as the blocks are always acquired in the same order.
