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authorNilay Vaish <nilay@cs.wisc.edu>2013-04-23 00:03:02 -0500
committerNilay Vaish <nilay@cs.wisc.edu>2013-04-23 00:03:02 -0500
commitaa86800e7a142f41a8fe957c367c133dea8d61bf (patch)
tree8d39b0c46569e171263c36de91f9b543502eb783 /src/mem/ruby/common
parente23e3bea8bc332626e026078dc8b23c983fc890f (diff)
downloadgem5-aa86800e7a142f41a8fe957c367c133dea8d61bf.tar.xz
ruby: patch checkpoint restore with garnet
Due to recent changes to clocking system in Ruby and the way Ruby restores state from a checkpoint, garnet was failing to run from a checkpointed state. The problem is that Ruby resets the time to zero while warming up the caches. If any component records a local copy of the time (read calls curCycle()) before the simulation has started, then that component will not operate until that time is reached. In the context of this particular patch, the Garnet Network class calls curCycle() at multiple places. Any non-operational component can block in requests in the memory system, which the system interprets as a deadlock. This patch makes changes so that Garnet can successfully run from checkpointed state. It adds a globally visible time at which the actual execution started. This time is initialized in RubySystem::startup() function. This variable is only meant for components with in Ruby. This replaces the private variable that was maintained within Garnet since it is not possible to figure out the correct time when the value of this variable can be set. The patch also does away with all cases where curCycle() is called with in some Ruby component before the system has actually started executing. This is required due to the quirky manner in which ruby restores from a checkpoint.
Diffstat (limited to 'src/mem/ruby/common')
-rw-r--r--src/mem/ruby/common/Global.cc1
-rw-r--r--src/mem/ruby/common/Global.hh5
2 files changed, 6 insertions, 0 deletions
diff --git a/src/mem/ruby/common/Global.cc b/src/mem/ruby/common/Global.cc
index 407e37307..3fdbd28b6 100644
--- a/src/mem/ruby/common/Global.cc
+++ b/src/mem/ruby/common/Global.cc
@@ -32,3 +32,4 @@ using namespace std;
RubySystem* g_system_ptr = 0;
vector<map<uint32_t, AbstractController *> > g_abs_controls;
+Cycles g_ruby_start;
diff --git a/src/mem/ruby/common/Global.hh b/src/mem/ruby/common/Global.hh
index 671f423f0..8282f5b01 100644
--- a/src/mem/ruby/common/Global.hh
+++ b/src/mem/ruby/common/Global.hh
@@ -33,6 +33,7 @@
#include <vector>
#include "base/str.hh"
+#include "base/types.hh"
class RubySystem;
extern RubySystem* g_system_ptr;
@@ -40,5 +41,9 @@ extern RubySystem* g_system_ptr;
class AbstractController;
extern std::vector<std::map<uint32_t, AbstractController *> > g_abs_controls;
+// A globally visible time at which the actual execution started. Meant only
+// for components with in Ruby. Initialized in RubySystem::startup().
+extern Cycles g_ruby_start;
+
#endif // __MEM_RUBY_COMMON_GLOBAL_HH__