diff options
author | Andreas Hansson <andreas.hansson@arm.com> | 2015-03-02 04:00:35 -0500 |
---|---|---|
committer | Andreas Hansson <andreas.hansson@arm.com> | 2015-03-02 04:00:35 -0500 |
commit | f26a28929583f2ed7fb55521e49c3f9bef557c05 (patch) | |
tree | e5d71fc69566b02a394015776b0f3f4e3be81427 /src/mem/cache/base.hh | |
parent | 6ebe8d863ae0c5a7799e9421da32593ac35e1cc7 (diff) | |
download | gem5-f26a28929583f2ed7fb55521e49c3f9bef557c05.tar.xz |
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.
Diffstat (limited to 'src/mem/cache/base.hh')
-rw-r--r-- | src/mem/cache/base.hh | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/src/mem/cache/base.hh b/src/mem/cache/base.hh index beb818961..bda3df34a 100644 --- a/src/mem/cache/base.hh +++ b/src/mem/cache/base.hh @@ -125,20 +125,20 @@ class BaseCache : public MemObject /** * Schedule a send of a request packet (from the MSHR). Note - * that we could already have a retry or a transmit list of - * responses outstanding. + * that we could already have a retry outstanding. */ void requestBus(RequestCause cause, Tick time) { DPRINTF(CachePort, "Asserting bus request for cause %d\n", cause); - queue.schedSendEvent(time); + reqQueue.schedSendEvent(time); } protected: CacheMasterPort(const std::string &_name, BaseCache *_cache, - MasterPacketQueue &_queue) : - QueuedMasterPort(_name, _cache, _queue) + ReqPacketQueue &_reqQueue, + SnoopRespPacketQueue &_snoopRespQueue) : + QueuedMasterPort(_name, _cache, _reqQueue, _snoopRespQueue) { } /** @@ -176,7 +176,7 @@ class BaseCache : public MemObject const std::string &_label); /** A normal packet queue used to store responses. */ - SlavePacketQueue queue; + RespPacketQueue queue; bool blocked; |