Go to file
Joel Hestness 1f2e7c1aaa sim: Don't quiesce UDelayEvents with 0 latency
ARM uses UDelayEvents to emulate kernel __*udelay functions and speed up
simulation. UDelayEvents call Pseudoinst::quiesceNs to quiesce the system for
a specified delay. Changeset 10341:0b4d10f53c2d introduced the requirement
that any quiesce process that is started must also be completed by scheduling
an EndQuiesceEvent. This change causes the CPU to hang if an IsQuiesce
instruction is executed, but the corresponding EndQuiesceEvent is not
scheduled.

Changeset 11058:d0934b57735a introduces a fix for uses of PseudoInst::quiesce*
that would conditionally execute the EndQuiesceEvent. ARM UDelayEvents specify
quiesce period of 0 ns (src/arch/arm/linux/system.cc), so changeset 11058
causes these events to now execute full quiesce processes, greatly increasing
the total instructions executed in kernel delay loops and slowing simulation.

This patch updates the UDelayEvent to conditionally execute
PseudoInst::quiesceNs (**a quiesce operation**) only if the specified
delay is >0 ns. The result is ARM delay loops no longer execute instructions
for quiesce handling, and regression time returns to normal.
2015-10-10 16:45:38 -05:00
build_opts scons: Do not build the InOrderCPU 2015-01-20 08:12:45 -05:00
configs config: Fix 'learning gem5' configs after SMT push 2015-10-01 04:07:15 -04:00
ext ext: fix SST connector 2015-10-06 18:08:28 -05:00
src sim: Don't quiesce UDelayEvents with 0 latency 2015-10-10 16:45:38 -05:00
system arm: Add support for ARMv8 (AArch64 & AArch32) 2014-01-24 15:29:34 -06:00
tests tests: Update SMT tests to correctly configure CPUs 2015-10-05 13:13:23 -05:00
util base: remove Trace::enabled flag 2015-09-30 15:21:55 -05:00
.hgignore ext: Add a McPAT regression tester 2014-06-04 07:48:20 -07:00
.hgtags Added tag stable_2015_09_03 for changeset 60eb3fef9c2d 2015-09-03 15:38:46 -05:00
COPYING copyright: Add code for finding all copyright blocks and create a COPYING file 2011-06-02 17:36:07 -07:00
LICENSE copyright: Add code for finding all copyright blocks and create a COPYING file 2011-06-02 17:36:07 -07:00
README misc: README direct to website for dependencies 2014-08-26 10:12:04 -04:00
SConstruct ext: Add the NoMali GPU no-simulation library 2015-07-07 10:03:13 +01:00

This is the gem5 simulator.

The main website can be found at http://www.gem5.org

A good starting point is http://www.gem5.org/Introduction, and for
more information about building the simulator and getting started
please see http://www.gem5.org/Documentation and
http://www.gem5.org/Tutorials.

To build gem5, you will need the following software: g++ or clang,
Python (gem5 links in the Python interpreter), SCons, SWIG, zlib, m4,
and lastly protobuf if you want trace capture and playback
support. Please see http://www.gem5.org/Dependencies for more details
concerning the minimum versions of the aforementioned tools.

Once you have all dependencies resolved, type 'scons
build/<ARCH>/gem5.opt' where ARCH is one of ALPHA, ARM, NULL, MIPS,
POWER, SPARC, or X86. This will build an optimized version of the gem5
binary (gem5.opt) for the the specified architecture. See
http://www.gem5.org/Build_System for more details and options.

With the simulator built, have a look at
http://www.gem5.org/Running_gem5 for more information on how to use
gem5.

The basic source release includes these subdirectories:
   - configs: example simulation configuration scripts
   - ext: less-common external packages needed to build gem5
   - src: source code of the gem5 simulator
   - system: source for some optional system software for simulated systems
   - tests: regression tests
   - util: useful utility programs and files

To run full-system simulations, you will need compiled system firmware
(console and PALcode for Alpha), kernel binaries and one or more disk
images. Please see the gem5 download page for these items at
http://www.gem5.org/Download

If you have questions, please send mail to gem5-users@gem5.org

Enjoy using gem5 and please share your modifications and extensions.