From c32b2ac795686d3292d8442d0091c42b17b61797 Mon Sep 17 00:00:00 2001 From: Tiago Muck Date: Mon, 4 Mar 2019 16:42:13 -0600 Subject: [PATCH] mem: Parameterize coherent xbar sanity checks Parameters can be used to change coherent xbar limits for the routing table and outstanding snoops. We need the ability to tweak these values as the current defaults may be violated in simulations with large core counts. Change-Id: Idb64b8c105683d02d8beba5bce13b815181ba824 Signed-off-by: Tiago Muck Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/18789 Reviewed-by: Daniel Carvalho Reviewed-by: Nikos Nikoleris Maintainer: Nikos Nikoleris Tested-by: kokoro --- src/mem/XBar.py | 8 +++++++- src/mem/coherent_xbar.cc | 19 ++++++++++++------- src/mem/coherent_xbar.hh | 13 ++++++++++++- 3 files changed, 31 insertions(+), 9 deletions(-) diff --git a/src/mem/XBar.py b/src/mem/XBar.py index 976a290eb..dab961fed 100644 --- a/src/mem/XBar.py +++ b/src/mem/XBar.py @@ -1,4 +1,4 @@ -# Copyright (c) 2012, 2015, 2017 ARM Limited +# Copyright (c) 2012, 2015, 2017, 2019 ARM Limited # All rights reserved. # # The license below extends only to copyright in the software and shall @@ -101,6 +101,12 @@ class CoherentXBar(BaseXBar): # An optional snoop filter snoop_filter = Param.SnoopFilter(NULL, "Selected snoop filter") + # Maximum number of outstanding snoop requests for sanity checks + max_outstanding_snoops = Param.Int(512, "Max. outstanding snoops allowed") + + # Maximum routing table size for sanity checks + max_routing_table_size = Param.Int(512, "Max. routing table size") + # Determine how this crossbar handles packets where caches have # already committed to responding, by establishing if the crossbar # is the point of coherency or not. diff --git a/src/mem/coherent_xbar.cc b/src/mem/coherent_xbar.cc index 839d95b9d..74c93be0f 100644 --- a/src/mem/coherent_xbar.cc +++ b/src/mem/coherent_xbar.cc @@ -1,5 +1,5 @@ /* - * Copyright (c) 2011-2018 ARM Limited + * Copyright (c) 2011-2019 ARM Limited * All rights reserved * * The license below extends only to copyright in the software and shall @@ -59,6 +59,8 @@ CoherentXBar::CoherentXBar(const CoherentXBarParams *p) : BaseXBar(p), system(p->system), snoopFilter(p->snoop_filter), snoopResponseLatency(p->snoop_response_latency), + maxOutstandingSnoopCheck(p->max_outstanding_snoops), + maxRoutingTableSizeCheck(p->max_routing_table_size), pointOfCoherency(p->point_of_coherency), pointOfUnification(p->point_of_unification) { @@ -325,8 +327,9 @@ CoherentXBar::recvTimingReq(PacketPtr pkt, PortID slave_port_id) outstandingSnoop.insert(pkt->req); // basic sanity check on the outstanding snoops - panic_if(outstandingSnoop.size() > 512, - "Outstanding snoop requests exceeded 512\n"); + panic_if(outstandingSnoop.size() > maxOutstandingSnoopCheck, + "%s: Outstanding snoop requests exceeded %d\n", + name(), maxOutstandingSnoopCheck); } // remember where to route the normal response to @@ -334,8 +337,9 @@ CoherentXBar::recvTimingReq(PacketPtr pkt, PortID slave_port_id) assert(routeTo.find(pkt->req) == routeTo.end()); routeTo[pkt->req] = slave_port_id; - panic_if(routeTo.size() > 512, - "Routing table exceeds 512 packets\n"); + panic_if(routeTo.size() > maxRoutingTableSizeCheck, + "%s: Routing table exceeds %d packets\n", + name(), maxRoutingTableSizeCheck); } // update the layer state and schedule an idle event @@ -401,8 +405,9 @@ CoherentXBar::recvTimingReq(PacketPtr pkt, PortID slave_port_id) assert(routeTo.find(pkt->req) == routeTo.end()); routeTo[pkt->req] = slave_port_id; - panic_if(routeTo.size() > 512, - "Routing table exceeds 512 packets\n"); + panic_if(routeTo.size() > maxRoutingTableSizeCheck, + "%s: Routing table exceeds %d packets\n", + name(), maxRoutingTableSizeCheck); } } } diff --git a/src/mem/coherent_xbar.hh b/src/mem/coherent_xbar.hh index ff28cb743..386b479f7 100644 --- a/src/mem/coherent_xbar.hh +++ b/src/mem/coherent_xbar.hh @@ -1,5 +1,5 @@ /* - * Copyright (c) 2011-2015, 2017 ARM Limited + * Copyright (c) 2011-2015, 2017, 2019 ARM Limited * All rights reserved * * The license below extends only to copyright in the software and shall @@ -278,8 +278,19 @@ class CoherentXBar : public BaseXBar * broadcast needed for probes. NULL denotes an absent filter. */ SnoopFilter *snoopFilter; + /** Cycles of snoop response latency.*/ const Cycles snoopResponseLatency; + + /** Maximum number of outstading snoops sanity check*/ + const unsigned int maxOutstandingSnoopCheck; + + /** Maximum routing table size sanity check*/ + const unsigned int maxRoutingTableSizeCheck; + + /** Is this crossbar the point of coherency? **/ const bool pointOfCoherency; + + /** Is this crossbar the point of unification? **/ const bool pointOfUnification; /** -- 2.30.2