From 8fb74c238cbf7a394d5d547dea987e35eddfca79 Mon Sep 17 00:00:00 2001 From: Korey Sewell Date: Wed, 27 Feb 2008 17:50:29 -0500 Subject: [PATCH] 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 --- src/cpu/o3/cpu.cc | 7 ++++++- src/cpu/o3/free_list.hh | 12 +++++++++++- 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::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 -- 2.30.2