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authorKorey Sewell <ksewell@umich.edu>2008-02-27 17:50:29 -0500
committerKorey Sewell <ksewell@umich.edu>2008-02-27 17:50:29 -0500
commit8fb74c238cbf7a394d5d547dea987e35eddfca79 (patch)
treefc5c67f02bc8c67956b0dcb57c26425ca0c8e6b9
parentb45cf21a8e2ead22996daa0960747db8ec95db71 (diff)
downloadgem5-8fb74c238cbf7a394d5d547dea987e35eddfca79.tar.xz
Add comments in code to describe bug conditions.
This should help if somebody gets to the bug fix before me (or someone else)... --HG-- extra : convert_revision : 0ae64c58ef4f7b02996f31e9e9e6bfad344719e2
-rw-r--r--src/cpu/o3/cpu.cc7
-rw-r--r--src/cpu/o3/free_list.hh12
2 files changed, 17 insertions, 2 deletions
diff --git a/src/cpu/o3/cpu.cc b/src/cpu/o3/cpu.cc
index 84aea0479..c75a08213 100644
--- a/src/cpu/o3/cpu.cc
+++ b/src/cpu/o3/cpu.cc
@@ -671,7 +671,12 @@ FullO3CPU<Impl>::removeThread(unsigned tid)
// Copy Thread Data From RegFile
// If thread is suspended, it might be re-allocated
- //this->copyToTC(tid);
+ // this->copyToTC(tid);
+
+
+ // @todo: 2-27-2008: Fix how we free up rename mappings
+ // here to alleviate the case for double-freeing registers
+ // in SMT workloads.
// Unbind Int Regs from Rename Map
for (int ireg = 0; ireg < TheISA::NumIntRegs; ireg++) {
diff --git a/src/cpu/o3/free_list.hh b/src/cpu/o3/free_list.hh
index d05068800..97b56909e 100644
--- a/src/cpu/o3/free_list.hh
+++ b/src/cpu/o3/free_list.hh
@@ -174,7 +174,17 @@ SimpleFreeList::addReg(PhysRegIndex freed_reg)
freeFloatRegs.push(freed_reg);
}
- //assert(freeIntRegs.size() <= numPhysicalIntRegs);
+ // These assert conditions ensure that the number of free
+ // registers are not more than the # of total Physical Registers.
+ // If this were false, it would mean that registers
+ // have been freed twice, overflowing the free register
+ // pool and potentially crashing SMT workloads.
+ // ----
+ // Comment out for now so as to not potentially break
+ // CMP and single-threaded workloads
+ // ----
+ // assert(freeIntRegs.size() <= numPhysicalIntRegs);
+ // assert(freeFloatRegs.size() <= numPhysicalFloatRegs);
}
inline void