3 files changed, 18 insertions, 5 deletions

diff --git a/src/cpu/simple/atomic.cc b/src/cpu/simple/atomic.cc
index c09f0c526..6c31f1ddd 100644
--- a/src/cpu/simple/atomic.cc
+++ b/src/cpu/simple/atomic.cc
@@ -628,6 +628,7 @@ AtomicSimpleCPU::tick()
 
             preExecute();
 
+            Tick stall_ticks = 0;
             if (curStaticInst) {
                 fault = curStaticInst->execute(&t_info, traceData);
 
@@ -641,6 +642,13 @@ AtomicSimpleCPU::tick()
                     traceData = NULL;
                 }
 
+                if (dynamic_pointer_cast<SyscallRetryFault>(fault)) {
+                    // Retry execution of system calls after a delay.
+                    // Prevents immediate re-execution since conditions which
+                    // caused the retry are unlikely to change every tick.
+                    stall_ticks += clockEdge(syscallRetryLatency) - curTick();
+                }
+
                 postExecute();
             }
 
@@ -649,7 +657,6 @@ AtomicSimpleCPU::tick()
                         curStaticInst->isFirstMicroop()))
                 instCnt++;
 
-            Tick stall_ticks = 0;
             if (simulate_inst_stalls && icache_access)
                 stall_ticks += icache_latency;
 
diff --git a/src/cpu/simple/exec_context.hh b/src/cpu/simple/exec_context.hh
index 430790c09..bfae118ad 100644
--- a/src/cpu/simple/exec_context.hh
+++ b/src/cpu/simple/exec_context.hh
@@ -323,12 +323,12 @@ class SimpleExecContext : public ExecContext {
     /**
      * Executes a syscall specified by the callnum.
      */
-    void syscall(int64_t callnum) override
+    void syscall(int64_t callnum, Fault *fault) override
     {
         if (FullSystem)
             panic("Syscall emulation isn't available in FS mode.");
 
-        thread->syscall(callnum);
+        thread->syscall(callnum, fault);
     }
 
     /** Returns a pointer to the ThreadContext. */
diff --git a/src/cpu/simple/timing.cc b/src/cpu/simple/timing.cc
index 43c50b948..1c468dc99 100644
--- a/src/cpu/simple/timing.cc
+++ b/src/cpu/simple/timing.cc
@@ -670,9 +670,15 @@ TimingSimpleCPU::advanceInst(const Fault &fault)
         return;
 
     if (fault != NoFault) {
-        advancePC(fault);
         DPRINTF(SimpleCPU, "Fault occured, scheduling fetch event\n");
-        reschedule(fetchEvent, clockEdge(), true);
+
+        advancePC(fault);
+
+        Tick stall = dynamic_pointer_cast<SyscallRetryFault>(fault) ?
+                     clockEdge(syscallRetryLatency) : clockEdge();
+
+        reschedule(fetchEvent, stall, true);
+
         _status = Faulting;
         return;
     }