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authorRon Dreslinski <rdreslin@umich.edu>2004-11-12 14:40:07 -0500
committerRon Dreslinski <rdreslin@umich.edu>2004-11-12 14:40:07 -0500
commit501db90f2ce7c083294e7981d6ef78b1420d671a (patch)
treed817a12fc7a56902ea07637433b0c6e416a1d164 /cpu/memtest/memtest.cc
parente2de2ea192b23b32b5ca7578cc9b6660ef3e0404 (diff)
downloadgem5-501db90f2ce7c083294e7981d6ef78b1420d671a.tar.xz
Make changes so that coherence works on a timing bus for the top-level of caches.
This added a snoopResponse callback to the caches, and a NACK to requests. cpu/memtest/memtest.cc: Modified to work with do_events: No multiple requests to the same block outstanding at the same time from the same tester Using false sharing, each tester does only 1 byte access using it's id as the blk offset Allow for cycles before signaling deadlock, with do events it can take time to complete (NACK/blocked bus) cpu/memtest/memtest.hh: Updated to keep an id with each tester (used for address generation) Updated to keep a list of outstanding address to prevent multiple outstanding per tester //Should really look into doing store forwarding within the tester, then we can test more functionality --HG-- extra : convert_revision : 05fbcf547e4ffab9d220aeb73126ed787ca82239
Diffstat (limited to 'cpu/memtest/memtest.cc')
-rw-r--r--cpu/memtest/memtest.cc49
1 files changed, 46 insertions, 3 deletions
diff --git a/cpu/memtest/memtest.cc b/cpu/memtest/memtest.cc
index 6584a62ba..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,
@@ -111,6 +114,8 @@ MemTest::MemTest(const string &name,
noResponseCycles = 0;
numReads = 0;
tickEvent.schedule(0);
+
+ id = TESTER_ALLOCATOR++;
}
static void
@@ -127,6 +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) {
@@ -158,6 +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;
@@ -212,7 +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("");
}
@@ -232,6 +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) {
@@ -251,6 +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);
@@ -273,6 +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);
@@ -298,6 +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);
}