cache: don't allow dirty data in the i-cache

removes the optimization that forwards an exclusive copy to a requester on a
read, only for the i-cache. this optimization isn't necessary because we
typically won't be writing to the i-cache.
This commit is contained in:
Anthony Gutierrez 2012-07-27 16:08:04 -04:00
parent 2eb6b403c9
commit 7bf14aedbf

View file

@ -172,7 +172,7 @@ Cache<TagStore>::satisfyCpuSideRequest(PacketPtr pkt, BlkType *blk,
// on ReadExReq we give up our copy unconditionally
tags->invalidateBlk(blk);
} else if (blk->isWritable() && !pending_downgrade
&& !pkt->sharedAsserted()) {
&& !pkt->sharedAsserted() && !pkt->req->isInstFetch()) {
// we can give the requester an exclusive copy (by not
// asserting shared line) on a read request if:
// - we have an exclusive copy at this level (& below)
@ -180,7 +180,9 @@ Cache<TagStore>::satisfyCpuSideRequest(PacketPtr pkt, BlkType *blk,
// signaling another read request
// - no other cache above has a copy (otherwise it
// would have asseretd shared line on request)
// - we are not satisfying an instruction fetch (this
// prevents dirty data in the i-cache)
if (blk->isDirty()) {
// special considerations if we're owner:
if (!deferred_response && !isTopLevel) {