From: Tiago Mück <tiago.muck@arm.com>
Date: Fri, 21 Jun 2019 00:06:20 +0000 (-0500)
Subject: mem-ruby: fix possible MOESI_CMP deadlock
X-Git-Tag: v20.1.0.0~655
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=d9cb548d83fa81858599807f54b52e5be35a6b03;p=gem5.git

mem-ruby: fix possible MOESI_CMP deadlock

Freeing the L2 block only after local invalidates are acked in the OLSF
state may lead to a deadlock.

Change-Id: Ia4b60e5bc9e2d3315b874a8c6616478db6eb38c1
Signed-off-by: Tiago Mück <tiago.muck@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/21929
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
---

diff --git a/src/mem/ruby/protocol/MOESI_CMP_directory-L2cache.sm b/src/mem/ruby/protocol/MOESI_CMP_directory-L2cache.sm
index 3c7763f64..989410768 100644
--- a/src/mem/ruby/protocol/MOESI_CMP_directory-L2cache.sm
+++ b/src/mem/ruby/protocol/MOESI_CMP_directory-L2cache.sm
@@ -1910,6 +1910,9 @@ machine(MachineType:L2Cache, "Token protocol")
     i_allocateTBE;
     t_recordFwdXID;
     ee_sendLocalInv;
+    gg_clearLocalSharers;
+    checkCacheNoSharersNoOwner;
+    rr_deallocateL2CacheBlock;
     m_popRequestQueue;
   }
 
@@ -1921,10 +1924,7 @@ machine(MachineType:L2Cache, "Token protocol")
 
   transition(OLSF, All_Acks, I) {
     c_sendDataFromTBEToFwdGETX;
-    gg_clearLocalSharers;
     s_deallocateTBE;
-    checkCacheNoSharersNoOwner;
-    rr_deallocateL2CacheBlock;
     n_popTriggerQueue;
     wa_wakeUpDependents;
   }