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413 commits

Author SHA1 Message Date
Andreas Hansson 66df7b7fd4 config: Add the ability to read a config file using C++ and Python
This patch adds the ability to load in config.ini files generated from
gem5 into another instance of gem5 built without Python configuration
support. The intended use case is for configuring gem5 when it is a
library embedded in another simulation system.

A parallel config file reader is also provided purely in Python to
demonstrate the approach taken and to provided similar functionality
for as-yet-unknown use models. The Python configuration file reader
can read both .ini and .json files.

C++ configuration file reading:

A command line option has been added for scons to enable C++ configuration
file reading: --with-cxx-config

There is an example in util/cxx_config that shows C++ configuration in action.
util/cxx_config/README explains how to build the example.

Configuration is achieved by the object CxxConfigManager. It handles
reading object descriptions from a CxxConfigFileBase object which
wraps a config file reader. The wrapper class CxxIniFile is provided
which wraps an IniFile for reading .ini files. Reading .json files
from C++ would be possible with a similar wrapper and a JSON parser.

After reading object descriptions, CxxConfigManager creates
SimObjectParam-derived objects from the classes in the (generated with this
patch) directory build/ARCH/cxx_config

CxxConfigManager can then build SimObjects from those SimObjectParams (in an
order dictated by the SimObject-value parameters on other objects) and bind
ports of the produced SimObjects.

A minimal set of instantiate-replacing member functions are provided by
CxxConfigManager and few of the member functions of SimObject (such as drain)
are extended onto CxxConfigManager.

Python configuration file reading (configs/example/read_config.py):

A Python version of the reader is also supplied with a similar interface to
CxxConfigFileBase (In Python: ConfigFile) to config file readers.

The Python config file reading will handle both .ini and .json files.

The object construction strategy is slightly different in Python from the C++
reader as you need to avoid objects prematurely becoming the children of other
objects when setting parameters.

Port binding also needs to be strictly in the same port-index order as the
original instantiation.
2014-10-16 05:49:37 -04:00
Andrew Bardsley d8502ee46d config: Add a --without-python option to build process
Add the ability to build libgem5 without embedded Python or the
ability to configure with Python.

This is a prelude to a patch to allow config.ini files to be loaded
into libgem5 using only C++ which would make embedding gem5 within
other simulation systems easier.

This adds a few registration interfaces to things which cross
between Python and C++.  Namely: stats dumping and SimObject resolving
2014-10-16 05:49:32 -04:00
Andrew Lukefahr f94fd44991 sim: draining bug for fast-forwaring multiple cores
fix draining bug where multiple cores hit max_insts_any_thread simultaneously

Committed by: Nilay Vaish <nilay@cs.wisc.edu>
2014-10-11 15:02:22 -05:00
Andreas Hansson c81517c293 config: Add Current as a parameter type
This patch adds the Python parameter type Current, which is used for
the DRAM power modelling (to start with). With this addition we avoid
implicit unit assumptions.
2014-10-09 17:52:00 -04:00
Andreas Hansson 1f6d5f8f84 mem: Rename Bus to XBar to better reflect its behaviour
This patch changes the name of the Bus classes to XBar to better
reflect the actual timing behaviour. The actual instances in the
config scripts are not renamed, and remain as e.g. iobus or membus.

As part of this renaming, the code has also been clean up slightly,
making use of range-based for loops and tidying up some comments. The
only changes outside the bus/crossbar code is due to the delay
variables in the packet.

--HG--
rename : src/mem/Bus.py => src/mem/XBar.py
rename : src/mem/coherent_bus.cc => src/mem/coherent_xbar.cc
rename : src/mem/coherent_bus.hh => src/mem/coherent_xbar.hh
rename : src/mem/noncoherent_bus.cc => src/mem/noncoherent_xbar.cc
rename : src/mem/noncoherent_bus.hh => src/mem/noncoherent_xbar.hh
rename : src/mem/bus.cc => src/mem/xbar.cc
rename : src/mem/bus.hh => src/mem/xbar.hh
2014-09-20 17:18:32 -04:00
Andrew Bardsley 7329c0e20b config: Cleanup .json config file generation
This patch 'completes' .json config files generation by adding in the
SimObject references and String-valued parameters not currently
printed.

TickParamValues are also changed to print in the same tick-value
format as in .ini files.

This allows .json files to describe a system as fully as the .ini files
currently do.

This patch adds a new function config_value (which mirrors ini_str) to
each ParamValue and to SimObject.  This function can then be explicitly
changed to give different .json and .ini printing behaviour rather than
being written in terms of ini_str.
2014-09-20 17:17:42 -04:00
Geoffrey Blake b0e4de667a config: Fix vectorparam command line parsing
Parsing vectorparams from the command was slightly broken
in that it wouldn't accept the input that the help message
provided to the user and it didn't do the conversion
on the second code path used to convert the string input
to the actual internal representation.  This patch fixes these bugs.
2014-09-09 04:36:34 -04:00
Geoffrey Blake 31e4e475d9 config: Add port splicing capability to PortRef class
The new configuration scripts need the ability to splice
a simobject between a pair of ports that are already connected.
The primary use case is when a CommMonitor needs to be
created after the system is configured and then spliced between
the pair of ports it will monitor.
2014-09-03 07:43:03 -04:00
Mitch Hayenga 23c8540756 config: Change parsing of Addr so hex values work from scripts
When passed from a configuration script with a hexadecimal value (like
"0x80000000"), gem5 would error out. This is because it would call
"toMemorySize" which requires the argument to end with a size specifier (like
1MB, etc).

This modification makes it so raw hex values can be passed through Addr
parameters from the configuration scripts.
2014-09-03 07:42:20 -04:00
Geoffrey Blake 09b5003815 config: Add hooks to enable new config sys
This patch adds helper functions to SimObject.py, params.py and
simulate.py to enable the new configuration system.  Functions like
enumerateParams() in SimObject lets the config system auto-generate
command line options for simobjects to be modified on the command
line.

Params in params.py have __call__() added
to their definition to allow the argparse module to use them
as a type to check command input is in the proper format.
2014-08-10 05:39:13 -04:00
Andrew Bardsley bf78299f04 cpu: Add flag name printing to StaticInst
This patch adds a the member function StaticInst::printFlags to allow all
of an instruction's flags to be printed without using the individual
is... member functions or resorting to exposing the 'flags' vector

It also replaces the enum definition StaticInst::Flags with a
Python-generated enumeration and adds to the enum generation mechanism
in src/python/m5/params.py to allow Enums to be placed in namespaces
other than Enums or, alternatively, in wrapper structs allowing them to
be inherited by other classes (so populating that class's name-space
with the enumeration element names).
2014-05-09 18:58:47 -04:00
Geoffrey Blake 0c1913336a config: Avoid generating a reference to myself for Parent.any
The unproxy code for Parent.any can generate a circular reference
in certain situations with classes hierarchies like those in ClockDomain.py.
This patch solves this by marking ouself as visited to make sure the
search does not resolve to a self-reference.
2014-05-09 18:58:47 -04:00
Curtis Dunham ad019c5c58 scons: Require SWIG >= 2.0.4 and remove vector typemaps
SWIG commit fd666c1 (*) made it unnecessary for gem5 to have these
typemaps to handle Vector types.

* fd666c1440
2014-05-09 18:58:46 -04:00
Sascha Bischoff 2031c03c09 misc: Proper type check and import for PortRef
Rewriting the type checking around PortRef, which was interacting strangely
with other Python scripts.

Tested-by: stephan.diestelhorst@arm.com
2014-04-23 05:18:25 -04:00
Curtis Dunham fa4a262204 stats: better error message for uninitialized statistic
As suggested by Nathan Binkert in 2008:
http://permalink.gmane.org/gmane.comp.emulators.m5.users/2676
2014-02-10 18:24:20 -06:00
Stan Czerniawski 4f77bc230a misc: Fix -q (quiet) flag
Check the right flag.
2014-03-23 11:11:49 -04:00
Matt Horsnell 739c6df94e base: add support for probe points and common probes
The probe patch is motivated by the desire to move analytical and trace code
away from functional code. This is achieved by the probe interface which is
essentially a glorified observer model.

What this means to users:
* add a probe point and a "notify" call at the source of an "event"
* add an isolated module, that is being used to carry out *your* analysis (e.g. generate a trace)
* register that module as a probe listener
Note: an example is given for reference in src/cpu/o3/simple_trace.[hh|cc] and src/cpu/SimpleTrace.py

What is happening under the hood:
* every SimObject maintains has a ProbeManager.
* during initialization (src/python/m5/simulate.py) first regProbePoints and
  the regProbeListeners is called on each SimObject.  this hooks up the probe
  point notify calls with the listeners.

FAQs:
Why did you develop probe points:
* to remove trace, stats gathering, analytical code out of the functional code.
* the belief that probes could be generically useful.

What is a probe point:
* a probe point is used to notify upon a given event (e.g. cpu commits an instruction)

What is a probe listener:
* a class that handles whatever the user wishes to do when they are notified
  about an event.

What can be passed on notify:
* probe points are templates, and so the user can generate probes that pass any
  type of argument (by const reference) to a listener.

What relationships can be generated (1:1, 1:N, N:M etc):
* there isn't a restriction. You can hook probe points and listeners up in a
  1:1, 1:N, N:M relationship. They become useful when a number of modules
  listen to the same probe points. The idea being that you can add a small
  number of probes into the source code and develop a larger number of useful
  analysis modules that use information passed by the probes.

Can you give examples:
* adding a probe point to the cpu's commit method allows you to build a trace
  module (outputting assembler), you could re-use this to gather instruction
  distribution (arithmetic, load/store, conditional, control flow) stats.

Why is the probe interface currently restricted to passing a const reference:
* the desire, initially at least, is to allow an interface to observe
  functionality, but not to change functionality.
* of course this can be subverted by const-casting.

What is the performance impact of adding probes:
* when nothing is actively listening to the probes they should have a
  relatively minor impact. Profiling has suggested even with a large number of
  probes (60) the impact of them (when not active) is very minimal (<1%).
2014-01-24 15:29:30 -06:00
Andreas Hansson daa781d2db config: Make the Clock a Tick parameter like Latency/Frequency
This patch makes the Clock a TickParamValue just like
Latency/Frequency. There is no longer any need to distinguish it
(originally needed to support multiplication).
2014-01-24 15:29:29 -06:00
Steve Reinhardt d8c9b5431b python: provide better error message for wrapped C++ methods
If you successfully export a C++ SimObject method, but try to
invoke it from Python before the C++ object is created, you
get a confusing error that says the attribute does not exist,
making you question whether you successfully exported the
method at all.  In reality, your only problem is that you're
calling the method too soon.  This patch enhances the error
message to give you a better clue.
2014-01-03 17:08:43 -08:00
Steve Reinhardt ba9ec669bc python: don't die on assignment to cloned object
Updating the SimObject topology of a cloned hierarchy is a little
dangerous, in that cloning is a "deep copy" and the clone does not
inherit SimObject updates the same way it would inherit scalar
variable assignments.

However, because of various SimObject-valued proxy parameters,
like 'memories', 'clk_domain', and 'system', it turns out that
there are a number of implicit topology changes that happen at
instantiation, which means that these changes are impossible to
avoid.  So in order to make cloning systems useful, this error
has to go.  Changing it to a warning produces a lot of noise,
so it seems best just to delete it.
2014-01-03 17:08:42 -08:00
Nilay Vaish 50d250f514 sim: reset stats after startup
Currently statistics are reset after the initial / checkpoint state
has been loaded. But ruby does some checkpoint processing in its
startup() function. So the stats need to be reset after the startup()
function has been called. This patch moves the class to stats.reset()
to achieve this change in functionality.
2013-12-03 10:51:40 -06:00
Steve Reinhardt ext:(%2C%20Nilay%20Vaish%20%3Cnilay%40cs.wisc.edu%3E%2C%20Ali%20Saidi%20%3CAli.Saidi%40ARM.com%3E) de366a16f1 sim: simulate with multiple threads and event queues
This patch adds support for simulating with multiple threads, each of
which operates on an event queue.  Each sim object specifies which eventq
is would like to be on.  A custom barrier implementation is being added
using which eventqs synchronize.

The patch was tested in two different configurations:
1. ruby_network_test.py: in this simulation L1 cache controllers receive
   requests from the cpu. The requests are replied to immediately without
   any communication taking place with any other level.
2. twosys-tsunami-simple-atomic: this configuration simulates a client-server
   system which are connected by an ethernet link.

We still lack the ability to communicate using message buffers or ports. But
other things like simulation start and end, synchronizing after every quantum
are working.

Committed by: Nilay Vaish
2013-11-25 11:21:00 -06:00
Steve Reinhardt a2c21d47a8 tests: suppress output on switcheroo tests
The output from the switcheroo tests is voluminous and
(because it includes timestamps) highly sensitive to
minor changes, leading to extremely large updates to the
reference outputs.  This patch addresses this problem
by suppressing output from the tests.  An internal
parameter can be set to enable the output.  Wiring that
up to a command-line flag (perhaps even the rudimantary
-v/-q options in m5/main.py) is left for future work.
2013-11-14 15:03:42 -08:00
Andreas Hansson c9a8b7b147 sim: Clarify the difference between tracing and debugging
This patch changes the name the command-line options related to debug
output to all start with "debug" rather than being a mix of that and
"trace". It also makes it clear that the breakpoint time is specified
in ticks and not in cycles.
2013-11-01 11:56:13 -04:00
Geoffrey Blake 15938e0492 config: Fix handling of parents for simobject vectors
SimObjectVector objects did not provide the same interface to
the _parent attribute through get_parent() like a normal
SimObject.  It also handled assigning a _parent incorrectly
if objects in a SimObjectVector were changed post-creation,
leading to errors later when the simulator tried to execute.
This patch fixes these two omissions.
2013-10-31 13:41:13 -05:00
Geoffrey Blake 2b9138135e config: Fix ommission of number base in ethernet address param
The ethernet address param tries to convert a hexadecimal
string using int() in python, which defaults to base 10,
need to specify base 16 in this case.
2013-10-17 10:20:45 -05:00
Geoffrey Blake 3d582c767a config: Fix for port references generated multiple times
SimObjects are expected to only generate one port reference per
port belonging to them.  There is a subtle bug with using "not"
here as a VectorPort is seen as not having a reference if it is
either None or empty as per Python docs sec 9.9 for Standard operators.
Intended behavior is to only check if we have not created the reference.
2013-10-17 10:20:45 -05:00
Andreas Hansson fe5212f932 swig: Fix issue with circular import in 2.0.9/2.0.10
This patch fixes an issue which prevented gem5 from running when built
using swig 2.0.9 and 2.0.10. The generated event.py tried to import
m5.internal which in turn relied on importing event. This patch seems
to fix the problem, and so far has not caused any other issues.
2013-09-18 08:46:31 -04:00
Andreas Hansson 3b90f52b61 util: Add ini string as tooltip info in dot output
This patch adds the config ini string as a tooltip that can be
displayed in most browsers rendering the resulting svg. Certain
characters are modified for HTML output.

Tested on chrome and firefox.
2013-09-04 13:23:00 -04:00
Andreas Hansson fad36b35c6 util: Add colours to the dot output
This patch is adding a splash of colour to the dot output to make it
easier to distinguish objects of different types. As a bonus, the
pastel-colour palette also makes the output look like a something from
the 21st century.
2013-09-04 13:22:59 -04:00
Andreas Hansson 62cf785178 util: Add class name to dot graph and output to svg
This patch adds the class name to the label, creates some more space
by increasing the rank separation, and additionally outputs the graph
as an editable SVG in addition to the PDF.
2013-09-04 13:22:58 -04:00
Akash Bagdia e7e17f92db power: Add voltage domains to the clock domains
This patch adds the notion of voltage domains, and groups clock
domains that operate under the same voltage (i.e. power supply) into
domains. Each clock domain is required to be associated with a voltage
domain, and the latter requires the voltage to be explicitly set.

A voltage domain is an independently controllable voltage supply being
provided to section of the design. Thus, if you wish to perform
dynamic voltage scaling on a CPU, its clock domain should be
associated with a separate voltage domain.

The current implementation of the voltage domain does not take into
consideration cases where there are derived voltage domains running at
ratio of native voltage domains, as with the case where there can be
on-chip buck/boost (charge pumps) voltage regulation logic.

The regression and configuration scripts are updated with a generic
voltage domain for the system, and one for the CPUs.
2013-08-19 03:52:28 -04:00
Andreas Hansson 204df3b928 sim: Make MaxTick in Python match the one in C++
This patch aligns the MaxTick in Python with the one in C++. Thus,
both reflect the maximum value that an unsigned 64-bit integer can
have.
2013-07-18 08:29:08 -04:00
Andreas Hansson a0e551869c config: Remove Clock parameter multiplication
This patch removes the multiplication operator support for Clock
parameters as this functionality is now achieved by creating derived
clock domains.

Nate, this one is for you.
2013-06-27 05:49:50 -04:00
Andreas Hansson 5c7ebee434 x86: Move APIC clock divider to Python
This patch moves the 16x APIC clock divider to the Python code to
avoid the post-instantiation modifications to the clock. The x86 APIC
was the only object setting the clock after creation time and this
required some custom functionality and configuration. With this patch,
the clock multiplier is moved to the Python code and the objects are
instantiated with the appropriate clock.
2013-02-19 05:56:06 -05:00
Sascha Bischoff 2f3b322280 base: Add warn() and inform() to m5.utils for use from python
This patch adds two fuctions to m5.util, warn and inform, which mirror those
found in the C++ side of gem5. These are added in addition to the already
existing m5.util.panic and m5.util.fatal which already mirror the C++
functionality. This ensures that warning and information messages generated
by python are in the same format as those generated by C++.

Occurrences of
    print "Warning: %s..." % name
have been replaced with
    warn("%s...", name)
2013-02-15 17:40:10 -05:00
Andreas Sandberg b904bd5437 sim: Add a system-global option to bypass caches
Virtualized CPUs and the fastmem mode of the atomic CPU require direct
access to physical memory. We currently require caches to be disabled
when using them to prevent chaos. This is not ideal when switching
between hardware virutalized CPUs and other CPU models as it would
require a configuration change on each switch. This changeset
introduces a new version of the atomic memory mode,
'atomic_noncaching', where memory accesses are inserted into the
memory system as atomic accesses, but bypass caches.

To make memory mode tests cleaner, the following methods are added to
the System class:

 * isAtomicMode() -- True if the memory mode is 'atomic' or 'direct'.
 * isTimingMode() -- True if the memory mode is 'timing'.
 * bypassCaches() -- True if caches should be bypassed.

The old getMemoryMode() and setMemoryMode() methods should never be
used from the C++ world anymore.
2013-02-15 17:40:09 -05:00
Andreas Sandberg e5dca84c3f config: Move CPU handover logic to m5.switchCpus()
CPU switching consists of the following steps:
 1. Drain the system
 2. Switch out old CPUs (cpu.switchOut())
 3. Change the system timing mode to the mode the new CPUs require
 4. Flush caches if switching to hardware virtualization
 5. Inform new CPUs of the handover (cpu.takeOverFrom())
 6. Resume the system

m5.switchCpus() previously only did step 2 & 5. Since information
about the new processors' memory system requirements is now exposed,
do all of the steps above.

This patch adds automatic memory system switching and flush (if
needed) to switchCpus(). Additionally, it adds optional draining to
switchCpus(). This has the following implications:

* changeToTiming and changeToAtomic are no longer needed, so they have
  been removed.

* changeMemoryMode is only used internally, so it is has been renamed
  to be private.

* switchCpus requires a reference to the system containing the CPUs as
  its first parameter.

WARNING: This changeset breaks compatibility with existing
configuration scripts since it changes the signature of
m5.switchCpus().
2013-02-15 17:40:08 -05:00
Andreas Sandberg d4eca0591d base: Add support for newer versions of IPython
IPython is used for the interactive gem5 shell if it exists. IPython
made API changes in version 0.11. This patch adds support for IPython
version 0.11 and above.

--HG--
extra : rebase_source : 5388d0919adb58d97f49a1a637db48cba61283a3
2013-02-10 13:23:58 +01:00
Andreas Sandberg 10f1f8c6a4 base: Fix broken IPython argument handling
Prior to this changeset, we used to clear sys.argv before entering the
IPython shell. This caused some versions of IPython to crash because
they assume argv[0] to exist. The correct way of overriding the
arguments passed to IPython is to set the argv keyword argument when
initializing the shell.
2013-02-10 13:23:56 +01:00
Andreas Sandberg a7e0cbeb36 cpu: Introduce sanity checks when switching between CPUs
This patch introduces the following sanity checks when switching
between CPUs:

 * Check that the set of new and old CPUs do not overlap. Having an
   overlap between the set of new CPUs and the set of old CPUs is
   currently not supported. Doing such a switch used to result in the
   following assertion error:
     BaseCPU::takeOverFrom(BaseCPU*): \
       Assertion `!new_itb_port->isConnected()' failed.

 * Check that all new CPUs are in the switched out state.

 * Check that all old CPUs are in the switched in state.
2013-01-07 13:05:44 -05:00
Andreas Hansson 01c5598373 mem: Add interleaving bits to the address ranges
This patch adds support for interleaving bits for the address
ranges. What was previously just a start and end address, now has an
additional three fields, for the high bit, and number of bits to use
for interleaving, and a match value to compare against. If the number
of interleaving bits is set to zero it is effectively disabled.

A number of convenience functions are added to the range to enquire
about the interleaving, its granularity and the number of stripes it
is part of.
2013-01-07 13:05:38 -05:00
Andreas Hansson e6c57786a4 config: Traverse lists when visiting children in all proxy
This patch makes the all proxy traverse any potential list that is
encountered in the object hierarchy instead of only looking at
children that are SimObjects. An example of where this is useful is
when creating a multi-channel memory system as a list of controllers,
whilst ensuring that the memories are still visible in the system.
2013-01-07 13:05:38 -05:00
Andreas Sandberg 050f24c796 sim: Add drain methods to request additional cleanup operations
This patch adds the following two methods to the Drainable base class:

memWriteback() - Write back all dirty cache lines to memory using
functional accesses.

memInvalidate() - Invalidate memory system buffers. Dirty data
won't be written back.

Specifying calling memWriteback() after draining will allow us to
checkpoint systems with caches. memInvalidate() can be used to drop
memory system buffers in preparation for switching to an accelerated
CPU model that bypasses the gem5 memory system (e.g., hardware
virtualized CPUs).

Note: This patch only adds the methods to Drainable, the code for
flushing the TLB and the cache is committed separately.
2012-11-02 11:32:02 -05:00
Andreas Sandberg aae6134b54 sim: Add SWIG interface for Serializable
This changeset adds a SWIG interface for the Serializable class, which
fixes a warning when compiling the SWIG interface for the event
queue. Currently, the only method exported is the name() method.
2012-11-02 11:32:02 -05:00
Andreas Sandberg dc01535c7e python: Rename doDrain()->drain() and make it do the right thing
There is no point in exporting the old drain() method in
Simulate.py. It should only be used internally by doDrain(). This
patch moves the old drain() method into doDrain() and renames
doDrain() to drain().
2012-11-02 11:32:02 -05:00
Andreas Sandberg 196397fea4 sim: Reuse the code to change memory mode.
changeToAtomic and changeToTiming both do essentially the same thing,
they check the type of their input argument, drain the system, and
switch to the desired memory mode. This patch moves all of that code
to a separate method (changeMemoryMode) and calls that from both
changeToAtomic and changeToTiming.
2012-11-02 11:32:02 -05:00
Andreas Sandberg b81a977e6a sim: Move the draining interface into a separate base class
This patch moves the draining interface from SimObject to a separate
class that can be used by any object needing draining. However,
objects not visible to the Python code (i.e., objects not deriving
from SimObject) still depend on their parents informing them when to
drain. This patch also gets rid of the CountedDrainEvent (which isn't
really an event) and replaces it with a DrainManager.
2012-11-02 11:32:01 -05:00
Andreas Sandberg c0ab52799c sim: Include object header files in SWIG interfaces
When casting objects in the generated SWIG interfaces, SWIG uses
classical C-style casts ( (Foo *)bar; ). In some cases, this can
degenerate into the equivalent of a reinterpret_cast (mainly if only a
forward declaration of the type is available). This usually works for
most compilers, but it is known to break if multiple inheritance is
used anywhere in the object hierarchy.

This patch introduces the cxx_header attribute to Python SimObject
definitions, which should be used to specify a header to include in
the SWIG interface. The header should include the declaration of the
wrapped object. We currently don't enforce header the use of the
header attribute, but a warning will be generated for objects that do
not use it.
2012-11-02 11:32:01 -05:00
Andreas Sandberg 7e25052fee Partly revert [4f54b0f229b5] and move draining to m5.changeToTiming
Changeset 4f54b0f229b5 removed the call to doDrain in changeToTiming
based on the assumption that the system does not need draining when
running in atomic mode. This is a false assumption since at least the
System class requires the system to be drained before it allows
switching of memory modes. This patch reverts that part of the
changeset.
2012-11-02 11:32:00 -05:00