ruby: Fix RubySystem warm-up and cool-down scope

The processes of warming up and cooling down Ruby caches are simulation-wide
processes, not just RubySystem instance-specific processes. Thus, the warm-up
and cool-down variables should be globally visible to any Ruby components
participating in either process. Make these variables static members and track
the warm-up and cool-down processes as appropriate.

This patch also has two side benefits:
1) It removes references to the RubySystem g_system_ptr, which are problematic
for allowing multiple RubySystem instances in a single simulation. Warmup and
cooldown variables being static (global) reduces the need for instance-specific
dereferences through the RubySystem.
2) From the AbstractController, it removes local RubySystem pointers, which are
used inconsistently with other uses of the RubySystem: 11 other uses reference
the RubySystem with the g_system_ptr. Only sequencers have local pointers.

1 files changed, 12 insertions, 6 deletions

diff --git a/src/mem/ruby/system/System.cc b/src/mem/ruby/system/System.cc
index b93dacdfc..75ebc8caf 100644
--- a/src/mem/ruby/system/System.cc
+++ b/src/mem/ruby/system/System.cc
@@ -49,6 +49,11 @@ bool RubySystem::m_randomization;
 uint32_t RubySystem::m_block_size_bytes;
 uint32_t RubySystem::m_block_size_bits;
 uint32_t RubySystem::m_memory_size_bits;
+bool RubySystem::m_warmup_enabled = false;
+// To look forward to allowing multiple RubySystem instances, track the number
+// of RubySystems that need to be warmed up on checkpoint restore.
+unsigned RubySystem::m_systems_to_warmup = 0;
+bool RubySystem::m_cooldown_enabled = false;
 
 RubySystem::RubySystem(const Params *p)
     : ClockedObject(p), m_access_backing_store(p->access_backing_store)
@@ -65,9 +70,6 @@ RubySystem::RubySystem(const Params *p)
     m_block_size_bits = floorLog2(m_block_size_bytes);
     m_memory_size_bits = p->memory_size_bits;
 
-    m_warmup_enabled = false;
-    m_cooldown_enabled = false;
-
     // Setup the global variables used in Ruby
     g_system_ptr = this;
 
@@ -252,6 +254,7 @@ RubySystem::unserialize(Checkpoint *cp, const string &section)
     readCompressedTrace(cache_trace_file, uncompressed_trace,
                         cache_trace_size);
     m_warmup_enabled = true;
+    m_systems_to_warmup++;
 
     vector<Sequencer*> sequencer_map;
     Sequencer* t = NULL;
@@ -307,7 +310,10 @@ RubySystem::startup()
 
         delete m_cache_recorder;
         m_cache_recorder = NULL;
-        m_warmup_enabled = false;
+        m_systems_to_warmup--;
+        if (m_systems_to_warmup == 0) {
+            m_warmup_enabled = false;
+        }
 
         // Restore eventq head
         eventq_head = eventq->replaceHead(eventq_head);
@@ -322,9 +328,9 @@ RubySystem::startup()
 void
 RubySystem::RubyEvent::process()
 {
-    if (ruby_system->m_warmup_enabled) {
+    if (RubySystem::getWarmupEnabled()) {
         ruby_system->m_cache_recorder->enqueueNextFetchRequest();
-    }  else if (ruby_system->m_cooldown_enabled) {
+    } else if (RubySystem::getCooldownEnabled()) {
         ruby_system->m_cache_recorder->enqueueNextFlushRequest();
     }
 }