From f26a28929583f2ed7fb55521e49c3f9bef557c05 Mon Sep 17 00:00:00 2001 From: Andreas Hansson Date: Mon, 2 Mar 2015 04:00:35 -0500 Subject: mem: Split port retry for all different packet classes This patch fixes a long-standing isue with the port flow control. Before this patch the retry mechanism was shared between all different packet classes. As a result, a snoop response could get stuck behind a request waiting for a retry, even if the send/recv functions were split. This caused message-dependent deadlocks in stress-test scenarios. The patch splits the retry into one per packet (message) class. Thus, sendTimingReq has a corresponding recvReqRetry, sendTimingResp has recvRespRetry etc. Most of the changes to the code involve simply clarifying what type of request a specific object was accepting. The biggest change in functionality is in the cache downstream packet queue, facing the memory. This queue was shared by requests and snoop responses, and it is now split into two queues, each with their own flow control, but the same physical MasterPort. These changes fixes the previously seen deadlocks. --- src/dev/dma_device.cc | 2 +- src/dev/dma_device.hh | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) (limited to 'src/dev') diff --git a/src/dev/dma_device.cc b/src/dev/dma_device.cc index d53ea2546..f6e476a8e 100644 --- a/src/dev/dma_device.cc +++ b/src/dev/dma_device.cc @@ -146,7 +146,7 @@ DmaPort::drain(DrainManager *dm) } void -DmaPort::recvRetry() +DmaPort::recvReqRetry() { assert(transmitList.size()); trySendTimingReq(); diff --git a/src/dev/dma_device.hh b/src/dev/dma_device.hh index 6df4a287d..933cbeb00 100644 --- a/src/dev/dma_device.hh +++ b/src/dev/dma_device.hh @@ -134,7 +134,7 @@ class DmaPort : public MasterPort protected: bool recvTimingResp(PacketPtr pkt); - void recvRetry() ; + void recvReqRetry() ; void queueDma(PacketPtr pkt); -- cgit v1.2.3