From d3ec34201c14d551e864372a89ccddb1c255e77a Mon Sep 17 00:00:00 2001 From: Nikos Nikoleris Date: Mon, 9 Oct 2017 13:57:49 +0100 Subject: cpu-o3: Prevent cpu from suspending if it is already draining Suspending the current thread context while draining due to a quiesce pseudo instruction (for example a wfi instruction) could deadlock the cpu and prevent it from successfully draining. This change ensures that the cpu is not draining before suspending the thread context. Change-Id: I7c019847f5a870d4bc9ce2b19936bc3dc45e5fd7 Reviewed-by: Andreas Sandberg Reviewed-on: https://gem5-review.googlesource.com/5881 Reviewed-by: Jason Lowe-Power Maintainer: Andreas Sandberg --- src/cpu/o3/thread_context_impl.hh | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'src/cpu/o3') diff --git a/src/cpu/o3/thread_context_impl.hh b/src/cpu/o3/thread_context_impl.hh index fdaa35134..d9f84fb52 100755 --- a/src/cpu/o3/thread_context_impl.hh +++ b/src/cpu/o3/thread_context_impl.hh @@ -1,5 +1,5 @@ /* - * Copyright (c) 2010-2012, 2016 ARM Limited + * Copyright (c) 2010-2012, 2016-2017 ARM Limited * Copyright (c) 2013 Advanced Micro Devices, Inc. * All rights reserved * @@ -109,6 +109,11 @@ O3ThreadContext::suspend() if (thread->status() == ThreadContext::Suspended) return; + if (cpu->isDraining()) { + DPRINTF(O3CPU, "Ignoring suspend on TC due to pending drain\n"); + return; + } + thread->lastActivate = curTick(); thread->lastSuspend = curTick(); -- cgit v1.2.3