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authorNilay Vaish <nilay@cs.wisc.edu>2014-11-06 05:42:21 -0600
committerNilay Vaish <nilay@cs.wisc.edu>2014-11-06 05:42:21 -0600
commit0811f21f67493a77b0c5a69260715d7cce7341e7 (patch)
treea2d5bd98ccb5fa17637ff791f66184d220e0e341 /configs
parent3022d463fbe1f969aadf7284ade996539c9454f9 (diff)
downloadgem5-0811f21f67493a77b0c5a69260715d7cce7341e7.tar.xz
ruby: provide a backing store
Ruby's functional accesses are not guaranteed to succeed as of now. While this is not a problem for the protocols that are currently in the mainline repo, it seems that coherence protocols for gpus rely on a backing store to supply the correct data. The aim of this patch is to make this backing store configurable i.e. it comes into play only when a particular option: --access-backing-store is invoked. The backing store has been there since M5 and GEMS were integrated. The only difference is that earlier the system used to maintain the backing store and ruby's copy was write-only. Sometime last year, we moved to data being supplied supplied by ruby in SE mode simulations. And now we have patches on the reviewboard, which remove ruby's copy of memory altogether and rely completely on the system's memory to supply data. This patch adds back a SimpleMemory member to RubySystem. This member is used only if the option: access-backing-store is set to true. By default, the memory would not be accessed.
Diffstat (limited to 'configs')
-rw-r--r--configs/ruby/Ruby.py8
1 files changed, 8 insertions, 0 deletions
diff --git a/configs/ruby/Ruby.py b/configs/ruby/Ruby.py
index 35ff66a0c..b99e251d3 100644
--- a/configs/ruby/Ruby.py
+++ b/configs/ruby/Ruby.py
@@ -56,6 +56,9 @@ def define_options(parser):
default='2GHz',
help="Clock for blocks running at Ruby system's speed")
+ parser.add_option("--access-backing-store", action="store_true", default=False,
+ help="Should ruby maintain a second copy of memory")
+
# Options related to cache structure
parser.add_option("--ports", action="store", type="int", default=4,
help="used of transitions per cycle which is a proxy \
@@ -229,3 +232,8 @@ def create_system(options, full_system, system, piobus = None, dma_ports = []):
ruby._cpu_ports = cpu_sequencers
ruby.num_of_sequencers = len(cpu_sequencers)
ruby.random_seed = options.random_seed
+
+ # Create a backing copy of physical memory in case required
+ if options.access_backing_store:
+ ruby.phys_mem = SimpleMemory(range=AddrRange(options.mem_size),
+ in_addr_map=False)