mem: Fix WriteLineReq fill behaviour

This patch fixes issues in the interactions between deferred snoops
and WriteLineReq. More specifically, the patch addresses an issue
where deferred snoops caused assertion failures when being serviced on
the arrival of an InvalidateResp. The response packet was perceived to
be invalidating, when actually it is not for the cache that sent out
the original invalidation request.
This commit is contained in:
Andreas Hansson 2015-09-25 07:26:58 -04:00
parent 5570aa9e9a
commit 012dd52dc2

View file

@ -1228,7 +1228,7 @@ Cache::recvTimingResp(PacketPtr pkt)
// allow invalidation responses originating from write-line
// requests to be discarded
bool discard_invalidate = false;
bool is_invalidate = pkt->isInvalidate();
// First offset for critical word first calculations
int initial_offset = initial_tgt->pkt->getOffset(blkSize);
@ -1271,7 +1271,7 @@ Cache::recvTimingResp(PacketPtr pkt)
// treat as a fill, and discard the invalidation
// response
is_fill = true;
discard_invalidate = true;
is_invalidate = false;
}
if (is_fill) {
@ -1327,7 +1327,7 @@ Cache::recvTimingResp(PacketPtr pkt)
if (is_error)
tgt_pkt->copyError(pkt);
if (tgt_pkt->cmd == MemCmd::ReadResp &&
(pkt->isInvalidate() || mshr->hasPostInvalidate())) {
(is_invalidate || mshr->hasPostInvalidate())) {
// If intermediate cache got ReadRespWithInvalidate,
// propagate that. Response should not have
// isInvalidate() set otherwise.
@ -1353,7 +1353,7 @@ Cache::recvTimingResp(PacketPtr pkt)
assert(!is_error);
// response to snoop request
DPRINTF(Cache, "processing deferred snoop...\n");
assert(!(pkt->isInvalidate() && !mshr->hasPostInvalidate()));
assert(!(is_invalidate && !mshr->hasPostInvalidate()));
handleSnoop(tgt_pkt, blk, true, true, mshr->hasPostInvalidate());
break;
@ -1368,8 +1368,7 @@ Cache::recvTimingResp(PacketPtr pkt)
// an invalidate response stemming from a write line request
// should not invalidate the block, so check if the
// invalidation should be discarded
if ((pkt->isInvalidate() || mshr->hasPostInvalidate()) &&
!discard_invalidate) {
if (is_invalidate || mshr->hasPostInvalidate()) {
assert(blk != tempBlock);
tags->invalidate(blk);
blk->invalidate();