From 719eb033fe435133abf15501c249eec10d1c861f Mon Sep 17 00:00:00 2001 From: Andreas Sandberg Date: Tue, 15 Mar 2016 15:45:12 +0000 Subject: cpu: Replace the fastmem with a new CPU model The AtomicSimpleCPU used to be able to access memory directly to speed up simulation if no caches are used. This is fine as long as no switching between CPU models is required. In order to switch to a new CPU model that requires caches, we currently need to checkpoint the system and restore it into a new configuration. The new 'atomic_noncaching' memory mode provides a solution that avoids this issue since caches are bypassed in this mode. This changeset removes the old fastmem option from the AtomicSimpleCPU and introduces a new CPU, NonCachingSimpleCPU, which derives from the AtomicSimpleCPU. The NonCachingSimpleCPU uses the same mechanism as the AtomicSimpleCPU used to use when accessing memory in when fastmem was enabled. This changeset also introduces a new switcheroo test that tests switching between a NonCachingSimpleCPU and a TimingSimpleCPU with caches. Change-Id: If01893f9b37528b14f530c11ce6f53c097582c21 Signed-off-by: Andreas Sandberg Reviewed-on: https://gem5-review.googlesource.com/12419 Reviewed-by: Jason Lowe-Power Maintainer: Jason Lowe-Power --- configs/common/CpuConfig.py | 1 + configs/common/Options.py | 2 -- 2 files changed, 1 insertion(+), 2 deletions(-) (limited to 'configs/common') diff --git a/configs/common/CpuConfig.py b/configs/common/CpuConfig.py index d70e6cfa7..f0d009e95 100644 --- a/configs/common/CpuConfig.py +++ b/configs/common/CpuConfig.py @@ -69,6 +69,7 @@ def _cpu_subclass_tester(name): return tester is_kvm_cpu = _cpu_subclass_tester("BaseKvmCPU") +is_atomic_cpu = _cpu_subclass_tester("AtomicSimpleCPU") def get(name): """Get a CPU class from a user provided class name or alias.""" diff --git a/configs/common/Options.py b/configs/common/Options.py index 29ef74c9a..aed888191 100644 --- a/configs/common/Options.py +++ b/configs/common/Options.py @@ -164,8 +164,6 @@ def addCommonOptions(parser): parser.add_option("-l", "--lpae", action="store_true") parser.add_option("-V", "--virtualisation", action="store_true") - parser.add_option("--fastmem", action="store_true") - # dist-gem5 options parser.add_option("--dist", action="store_true", help="Parallel distributed gem5 simulation.") -- cgit v1.2.3