From 036263e28057ae39f5fd1df0cbd87094770add80 Mon Sep 17 00:00:00 2001 From: Andreas Hansson Date: Mon, 28 Dec 2015 11:14:10 -0500 Subject: [PATCH] mem: Fix cache sender state handling and add clarification This patch addresses a bug in how the cache attached the MSHR as a sender state. Rather than overwriting any existing sender state it now pushes a new one. The handling of upward snoops is also clarified. --- src/mem/cache/cache.cc | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/src/mem/cache/cache.cc b/src/mem/cache/cache.cc index 67e889453..187ed4801 100644 --- a/src/mem/cache/cache.cc +++ b/src/mem/cache/cache.cc @@ -2330,6 +2330,10 @@ Cache::getTimingPacket() // dirty one. Packet snoop_pkt(tgt_pkt, true, false); snoop_pkt.setExpressSnoop(); + // We are sending this packet upwards, but if it hits we will + // get a snoop response that we end up treating just like a + // normal response, hence it needs the MSHR as its sender + // state snoop_pkt.senderState = mshr; cpuSidePort->sendTimingSnoopReq(&snoop_pkt); @@ -2399,7 +2403,9 @@ Cache::getTimingPacket() } assert(pkt != NULL); - pkt->senderState = mshr; + // play it safe and append (rather than set) the sender state, as + // forwarded packets may already have existing state + pkt->pushSenderState(mshr); return pkt; }