1 files changed, 48 insertions, 4 deletions

diff --git a/cpu/memtest/memtest.cc b/cpu/memtest/memtest.cc
index b55af332a..e967c79da 100644
--- a/cpu/memtest/memtest.cc
+++ b/cpu/memtest/memtest.cc
@@ -28,9 +28,10 @@
 
 // FIX ME: make trackBlkAddr use blocksize from actual cache, not hard coded
 
-#include <string>
-#include <sstream>
 #include <iomanip>
+#include <set>
+#include <sstream>
+#include <string>
 #include <vector>
 
 #include "base/misc.hh"
@@ -44,6 +45,8 @@
 
 using namespace std;
 
+int TESTER_ALLOCATOR=0;
+
 MemTest::MemTest(const string &name,
                  MemInterface *_cache_interface,
                  FunctionalMemory *main_mem,
@@ -58,7 +61,8 @@ MemTest::MemTest(const string &name,
                  Addr _traceAddr,
                  Counter max_loads_any_thread,
                  Counter max_loads_all_threads)
-    : BaseCPU(name, 1, 0, 0, max_loads_any_thread, max_loads_all_threads),
+    : BaseCPU(name, 1, true, 0, 0, max_loads_any_thread,
+              max_loads_all_threads),
       tickEvent(this),
       cacheInterface(_cache_interface),
       mainMem(main_mem),
@@ -110,6 +114,8 @@ MemTest::MemTest(const string &name,
     noResponseCycles = 0;
     numReads = 0;
     tickEvent.schedule(0);
+
+    id = TESTER_ALLOCATOR++;
 }
 
 static void
@@ -126,6 +132,11 @@ printData(ostream &os, uint8_t *data, int nbytes)
 void
 MemTest::completeRequest(MemReqPtr &req, uint8_t *data)
 {
+    //Remove the address from the list of outstanding
+    std::set<unsigned>::iterator removeAddr = outstandingAddrs.find(req->paddr);
+    assert(removeAddr != outstandingAddrs.end());
+    outstandingAddrs.erase(removeAddr);
+
     switch (req->cmd) {
       case Read:
         if (memcmp(req->data, data, req->size) != 0) {
@@ -157,6 +168,10 @@ MemTest::completeRequest(MemReqPtr &req, uint8_t *data)
         break;
 
       case Copy:
+        //Also remove dest from outstanding list
+        removeAddr = outstandingAddrs.find(req->dest);
+        assert(removeAddr != outstandingAddrs.end());
+        outstandingAddrs.erase(removeAddr);
         numCopiesStat++;
         break;
 
@@ -211,7 +226,7 @@ MemTest::tick()
     if (!tickEvent.scheduled())
         tickEvent.schedule(curTick + 1);
 
-    if (++noResponseCycles >= 5000) {
+    if (++noResponseCycles >= 500000) {
         cerr << name() << ": deadlocked at cycle " << curTick << endl;
         fatal("");
     }
@@ -231,6 +246,16 @@ MemTest::tick()
     unsigned source_align = rand() % 100;
     unsigned dest_align = rand() % 100;
 
+    //If we aren't doing copies, use id as offset, and do a false sharing
+    //mem tester
+    if (percentCopies == 0) {
+        //We can eliminate the lower bits of the offset, and then use the id
+        //to offset within the blks
+        offset1 &= ~63; //Not the low order bits
+        offset1 += id;
+        access_size = 0;
+    }
+
     MemReqPtr req = new MemReq();
 
     if (cacheable < percentUncacheable) {
@@ -250,6 +275,13 @@ MemTest::tick()
 
     if (cmd < percentReads) {
         // read
+
+        //For now we only allow one outstanding request per addreess per tester
+        //This means we assume CPU does write forwarding to reads that alias something
+        //in the cpu store buffer.
+        if (outstandingAddrs.find(req->paddr) != outstandingAddrs.end()) return;
+        else outstandingAddrs.insert(req->paddr);
+
         req->cmd = Read;
         uint8_t *result = new uint8_t[8];
         checkMem->access(Read, req->paddr, result, req->size);
@@ -272,6 +304,13 @@ MemTest::tick()
         }
     } else if (cmd < (100 - percentCopies)){
         // write
+
+        //For now we only allow one outstanding request per addreess per tester
+        //This means we assume CPU does write forwarding to reads that alias something
+        //in the cpu store buffer.
+        if (outstandingAddrs.find(req->paddr) != outstandingAddrs.end()) return;
+        else outstandingAddrs.insert(req->paddr);
+
         req->cmd = Write;
         memcpy(req->data, &data, req->size);
         checkMem->access(Write, req->paddr, req->data, req->size);
@@ -297,6 +336,11 @@ MemTest::tick()
         // copy
         Addr source = ((base) ? baseAddr1 : baseAddr2) + offset1;
         Addr dest = ((base) ? baseAddr2 : baseAddr1) + offset2;
+        if (outstandingAddrs.find(source) != outstandingAddrs.end()) return;
+        else outstandingAddrs.insert(source);
+        if (outstandingAddrs.find(dest) != outstandingAddrs.end()) return;
+        else outstandingAddrs.insert(dest);
+
         if (source_align >= percentSourceUnaligned) {
             source = blockAddr(source);
         }