diff options
| -rw-r--r-- | src/mem/cache/cache.cc | 5 | ||||
| -rw-r--r-- | src/mem/cache/mshr.cc | 37 | ||||
| -rw-r--r-- | src/mem/cache/mshr.hh | 45 |
3 files changed, 59 insertions, 28 deletions
diff --git a/src/mem/cache/cache.cc b/src/mem/cache/cache.cc index e3f2777ef..db982c1f0 100644 --- a/src/mem/cache/cache.cc +++ b/src/mem/cache/cache.cc @@ -1318,7 +1318,7 @@ Cache::recvTimingResp(PacketPtr pkt) DPRINTF(Cache, "Block for addr %#llx being updated in Cache\n", pkt->getAddr()); - blk = handleFill(pkt, blk, writebacks, mshr->allocOnFill); + blk = handleFill(pkt, blk, writebacks, mshr->allocOnFill()); assert(blk != nullptr); } @@ -1369,7 +1369,8 @@ Cache::recvTimingResp(PacketPtr pkt) // any deferred targets if possible mshr->promoteWritable(); // NB: we use the original packet here and not the response! - blk = handleFill(tgt_pkt, blk, writebacks, mshr->allocOnFill); + blk = handleFill(tgt_pkt, blk, writebacks, + mshr->allocOnFill()); assert(blk != nullptr); // treat as a fill, and discard the invalidation diff --git a/src/mem/cache/mshr.cc b/src/mem/cache/mshr.cc index dd827ae12..86e77b186 100644 --- a/src/mem/cache/mshr.cc +++ b/src/mem/cache/mshr.cc @@ -65,17 +65,18 @@ using namespace std; MSHR::MSHR() : downstreamPending(false), pendingModified(false), postInvalidate(false), postDowngrade(false), - isForward(false), allocOnFill(false) + isForward(false) { } MSHR::TargetList::TargetList() - : needsWritable(false), hasUpgrade(false) + : needsWritable(false), hasUpgrade(false), allocOnFill(false) {} void -MSHR::TargetList::updateFlags(PacketPtr pkt, Target::Source source) +MSHR::TargetList::updateFlags(PacketPtr pkt, Target::Source source, + bool alloc_on_fill) { if (source != Target::FromSnoop) { if (pkt->needsWritable()) { @@ -88,6 +89,10 @@ MSHR::TargetList::updateFlags(PacketPtr pkt, Target::Source source) if (pkt->isUpgrade() || pkt->cmd == MemCmd::StoreCondReq) { hasUpgrade = true; } + + // potentially re-evaluate whether we should allocate on a fill or + // not + allocOnFill = allocOnFill || alloc_on_fill; } } @@ -96,15 +101,16 @@ MSHR::TargetList::populateFlags() { resetFlags(); for (auto& t: *this) { - updateFlags(t.pkt, t.source); + updateFlags(t.pkt, t.source, t.allocOnFill); } } inline void MSHR::TargetList::add(PacketPtr pkt, Tick readyTime, - Counter order, Target::Source source, bool markPending) + Counter order, Target::Source source, bool markPending, + bool alloc_on_fill) { - updateFlags(pkt, source); + updateFlags(pkt, source, alloc_on_fill); if (markPending) { // Iterate over the SenderState stack and see if we find // an MSHR entry. If we do, set the downstreamPending @@ -119,7 +125,7 @@ MSHR::TargetList::add(PacketPtr pkt, Tick readyTime, } } - emplace_back(pkt, readyTime, order, source, markPending); + emplace_back(pkt, readyTime, order, source, markPending, alloc_on_fill); } @@ -239,7 +245,6 @@ MSHR::allocate(Addr blk_addr, unsigned blk_size, PacketPtr target, order = _order; assert(target); isForward = false; - allocOnFill = alloc_on_fill; _isUncacheable = target->req->isUncacheable(); inService = false; downstreamPending = false; @@ -248,7 +253,7 @@ MSHR::allocate(Addr blk_addr, unsigned blk_size, PacketPtr target, // snoop (mem-side request), so set source according to request here Target::Source source = (target->cmd == MemCmd::HardPFReq) ? Target::FromPrefetcher : Target::FromCPU; - targets.add(target, when_ready, _order, source, true); + targets.add(target, when_ready, _order, source, true, alloc_on_fill); assert(deferredTargets.isReset()); } @@ -305,10 +310,6 @@ MSHR::allocateTarget(PacketPtr pkt, Tick whenReady, Counter _order, // have targets addded if originally allocated uncacheable assert(!_isUncacheable); - // potentially re-evaluate whether we should allocate on a fill or - // not - allocOnFill = allocOnFill || alloc_on_fill; - // if there's a request already in service for this MSHR, we will // have to defer the new target until after the response if any of // the following are true: @@ -326,13 +327,15 @@ MSHR::allocateTarget(PacketPtr pkt, Tick whenReady, Counter _order, // need to put on deferred list if (hasPostInvalidate()) replaceUpgrade(pkt); - deferredTargets.add(pkt, whenReady, _order, Target::FromCPU, true); + deferredTargets.add(pkt, whenReady, _order, Target::FromCPU, true, + alloc_on_fill); } else { // No request outstanding, or still OK to append to // outstanding request: append to regular target list. Only // mark pending if current request hasn't been issued yet // (isn't in service). - targets.add(pkt, whenReady, _order, Target::FromCPU, !inService); + targets.add(pkt, whenReady, _order, Target::FromCPU, !inService, + alloc_on_fill); } } @@ -431,7 +434,7 @@ MSHR::handleSnoop(PacketPtr pkt, Counter _order) // recipient does not care there is no harm in doing so } targets.add(cp_pkt, curTick(), _order, Target::FromSnoop, - downstreamPending && targets.needsWritable); + downstreamPending && targets.needsWritable, false); if (pkt->needsWritable()) { // This transaction will take away our pending copy @@ -527,7 +530,7 @@ MSHR::print(std::ostream &os, int verbosity, const std::string &prefix) const prefix, blkAddr, blkAddr + blkSize - 1, isSecure ? "s" : "ns", isForward ? "Forward" : "", - allocOnFill ? "AllocOnFill" : "", + allocOnFill() ? "AllocOnFill" : "", needsWritable() ? "Wrtbl" : "", _isUncacheable ? "Unc" : "", inService ? "InSvc" : "", diff --git a/src/mem/cache/mshr.hh b/src/mem/cache/mshr.hh index 253f5f388..437f8d4e4 100644 --- a/src/mem/cache/mshr.hh +++ b/src/mem/cache/mshr.hh @@ -128,11 +128,14 @@ class MSHR : public QueueEntry, public Printable const Source source; //!< Request from cpu, memory, or prefetcher? const bool markedPending; //!< Did we mark upstream MSHR //!< as downstreamPending? + const bool allocOnFill; //!< Should the response servicing this + //!< target list allocate in the cache? Target(PacketPtr _pkt, Tick _readyTime, Counter _order, - Source _source, bool _markedPending) + Source _source, bool _markedPending, bool alloc_on_fill) : recvTime(curTick()), readyTime(_readyTime), order(_order), - pkt(_pkt), source(_source), markedPending(_markedPending) + pkt(_pkt), source(_source), markedPending(_markedPending), + allocOnFill(alloc_on_fill) {} }; @@ -141,6 +144,8 @@ class MSHR : public QueueEntry, public Printable public: bool needsWritable; bool hasUpgrade; + /** Set when the response should allocate on fill */ + bool allocOnFill; TargetList(); @@ -150,10 +155,12 @@ class MSHR : public QueueEntry, public Printable * * @param pkt Packet considered for the flag update * @param source Indicates the source of the packet + * @param alloc_on_fill Whether the pkt would allocate on a fill */ - void updateFlags(PacketPtr pkt, Target::Source source); + void updateFlags(PacketPtr pkt, Target::Source source, + bool alloc_on_fill); - void resetFlags() { needsWritable = hasUpgrade = false; } + void resetFlags() { needsWritable = hasUpgrade = allocOnFill = false; } /** * Goes through the list of targets and uses them to populate @@ -163,9 +170,29 @@ class MSHR : public QueueEntry, public Printable */ void populateFlags(); - bool isReset() const { return !needsWritable && !hasUpgrade; } + /** + * Tests if the flags of this TargetList have their default + * values. + */ + bool isReset() const { + return !needsWritable && !hasUpgrade && !allocOnFill; + } + + /** + * Add the specified packet in the TargetList. This function + * stores information related to the added packet and updates + * accordingly the flags. + * + * @param pkt Packet considered for adding + * @param readTime Tick at which the packet is processed by this cache + * @param order A counter giving a unique id to each target + * @param source Indicates the source agent of the packet + * @param markPending Set for deferred targets or pending MSHRs + * @param alloc_on_fill Whether it should allocate on a fill + */ void add(PacketPtr pkt, Tick readyTime, Counter order, - Target::Source source, bool markPending); + Target::Source source, bool markPending, + bool alloc_on_fill); /** * Convert upgrades to the equivalent request if the cache line they @@ -184,9 +211,6 @@ class MSHR : public QueueEntry, public Printable /** MSHR list iterator. */ typedef List::iterator Iterator; - /** Keep track of whether we should allocate on fill or not */ - bool allocOnFill; - /** The pending* and post* flags are only valid if inService is * true. Using the accessor functions lets us detect if these * flags are accessed improperly. @@ -209,6 +233,9 @@ class MSHR : public QueueEntry, public Printable bool sendPacket(Cache &cache); + bool allocOnFill() const { + return targets.allocOnFill; + } private: /** |