The following patches had unexpected interactions with the current
upstream code and have been reverted for now:
e07fd01651f3: power: Add support for power models
831c7f2f9e39: power: Low-power idle power state for idle CPUs
4f749e00b667: power: Add power states to ClockedObject
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
--HG--
extra : amend_source : 0b6fb073c6bbc24be533ec431eb51fbf1b269508
This patch adds some basic support for power models in gem5.
The power interface is defined so it can interact with thermal
models as well. It implements a simple power evaluator that
can be used for simple power models that express power in the
form of a math expression. These expressions can use stats
within the same SimObject (or down its hierarchy) and some
magic variables such as "temp" for temperature.
In future patches we will extend this functionality to allow
slightly more complex expressions.
The model allows it to be extended to use other kinds of models.
Finally, the thermal model is updated to use the power usage as input.
Add 4 power states to the ClockedObject, provides necessary access functions
to check and update the power state. Default power state is UNDEFINED, it is
responsibility of the respective simulation model to provide the startup state
and any other logic for state change.
Add number of transition stat.
Add distribution of time spent in clock gated state.
Add power state residency stat.
Add dump call back function to allow stats update of distribution and residency
stats.
This patch adds basic thermal support to gem5. It models energy dissipation
through a circuital equivalent, which allows us to use RC networks.
This lays down the basic infrastructure to do so, but it does not "work" due
to the lack of power models. For now some hardcoded number is used as a PoC.
The solver is embedded in the patch.
This patch adds some additional information when draining the system which
allows the user to debug which SimObject(s) in the system is failing to drain.
Only enabled for the builds with tracing enabled and is subject to the Drain
debug flag being set at runtime.
This patch addresses an issue with the unserialization of clock
domains. Previously, the previous performance level was not restored
due to a bug in the code, which detected the post-unserialize update
as superfluous. This patch splits the setting of the clock domain into
two parts. The original interface of perfLevel is retained, but the
actual update takes place in signalPerfLevelUpdate, which is private
to the class. The perfLevel method checks that if the new performance
level is different to the previous performance level, and will only
call signalPerfLevelUpdate if there is a change. Therefore, the
performance level is only updated, and voltage domains notified, if
there is an actual change. The split functionality allows
signalPerfLevelUpdate to be called by startup() to explicitly force an
update post unserialization.
Libraries are loaded into the process address space using the
mmap system call. Conveniently, this happens to be a good
time to update the process symbol table with the library's
incoming symbols so we handle the table update from within the
system call.
This works just like an application's normal symbols. The only
difference between a dynamic library and a main executable is
when the symbol table update occurs. The symbol table update for
an executable happens at program load time and is finished before
the process ever begins executing. Since dynamic linking happens
at runtime, the symbol loading happens after the library is
first loaded into the process address space. The library binary
is examined at this time for a symbol section and that section
is parsed for symbol types with specific bindings (global,
local, weak). Subsequently, these symbols are added to the table
and are available for use by gem5 for things like trace
generation.
Checkpointing should work just as it did previously. The address
space (and therefore the library) will be recorded and the symbol
table will be entirely recorded. (It's not possible to do anything
clever like checkpoint a program and then load the program back
with different libraries with LD_LIBRARY_PATH, because the
library becomes part of the address space after being loaded.)
The mmapGrowsDown() method was a static method on the OperatingSystem
class (and derived classes), which worked OK for the templated syscall
emulation methods, but made it hard to access elsewhere. This patch
moves the method to be a virtual function on the LiveProcess method,
where it can be overridden for specific platforms (for now, Alpha).
This patch also changes the value of mmapGrowsDown() from being false
by default and true only on X86Linux32 to being true by default and
false only on Alpha, which seems closer to reality (though in reality
most people use ASLR and this doesn't really matter anymore).
In the process, also got rid of the unused mmap_start field on
LiveProcess and OperatingSystem mmapGrowsUp variable.
For O3, which has a stat that counts reg reads, there is an additional
reg read per mmap() call since there's an arg we no longer ignore.
Otherwise, stats should not be affected.
Breaks the debug output from system calls into two levels: Base and Verbose.
A macro is added specifically for system calls which allows developers to
easily add new debug messages in a consistent manner. The macro also contains
a field to print thread IDs along with the CPU ID.
Adding voltage function which returns the current voltage
for a given clocked object. It's handy for power models and
similar stuff that need to retrieve voltage. Function
frequency() is already there, so I see no reason for not having
this one too.
When forking a gem5 process, some objects need to clean up resources
(mainly file descriptions) shared between the child and the parent of
the fork. This changeset adds the notifyFork() method to Drainable,
which is called in the child process.
Signed-off-by: Andreas Sandberg <andreas@sandberg.pp.se>
[sascha.bischoff@arm.com: Rebased patches onto a newer gem5 version]
Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
This changeset adds support for changing the simulator output
directory. This can be useful when the simulation goes through several
stages (e.g., a warming phase, a simulation phase, and a verification
phase) since it allows the output from each stage to be located in a
different directory. Relocation is done by calling core.setOutputDir()
from Python or simout.setOutputDirectory() from C++.
This change affects several parts of the design of the gem5's output
subsystem. First, files returned by an OutputDirectory instance (e.g.,
simout) are of the type OutputStream instead of a std::ostream. This
allows us to do some more book keeping and control re-opening of files
when the output directory is changed. Second, new subdirectories are
OutputDirectory instances, which should be used to create files in
that sub-directory.
Signed-off-by: Andreas Sandberg <andreas@sandberg.pp.se>
[sascha.bischoff@arm.com: Rebased patches onto a newer gem5 version]
Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
By ignoring SIG_TRAP, using --debug-break <N> when not connected to
a debugger becomes a no-op. Apparently this was intended to be a
feature, though the rationale is not clear.
If we don't ignore SIG_TRAP, then using --debug-break <N> when not
connected to a debugger causes the simulation process to terminate
at tick N. This is occasionally useful, e.g., if you just want to
collect a trace for a specific window of execution then you can combine
this with --debug-start to do exactly that.
In addition to not ignoring the signal, this patch also updates
the --debug-break help message and deletes a handful of unprotected
calls to Debug::breakpoint() that relied on the prior behavior.
Distributed gem5 (abbreviated dist-gem5) is the result of the
convergence effort between multi-gem5 and pd-gem5 (from Univ. of
Wisconsin). It relies on the base multi-gem5 infrastructure for packet
forwarding, synchronisation and checkpointing but combines those with
the elaborated network switch model from pd-gem5.
--HG--
rename : src/dev/net/multi_etherlink.cc => src/dev/net/dist_etherlink.cc
rename : src/dev/net/multi_etherlink.hh => src/dev/net/dist_etherlink.hh
rename : src/dev/net/multi_iface.cc => src/dev/net/dist_iface.cc
rename : src/dev/net/multi_iface.hh => src/dev/net/dist_iface.hh
rename : src/dev/net/multi_packet.hh => src/dev/net/dist_packet.hh
When adding an option to forward work items to the Python environment,
the new behavior was accidentally enabled by default. Set the value of
exit_on_work_items to False by default to revert to the old behavior
unless the simulation scripts explicitly requests work item
forwarding.
There are cases where we want the Python world to handle work items
instead of the C++ world. However, that's currently not possible. This
changeset adds the forward_work_items option to the System class. Then
it is set to True, work items will generate workbegin/workend
simulation exists with the work item ID as the exit code and the old
C++ handling is completely bypassed.
--HG--
extra : rebase_source : 8de637a744fc4b6ff2bc763f00cdf8ddf2bff885
The writefile pseudo instruction uses OutputDirectory::create and
OutputDirectory::openFile to create the output files. However, by
default these will check the file extention for .gz, and create a gzip
compressed stream if the file ending matches. When writing out files,
we want to write them out exactly as they are in the guest simulation,
and never want to compress them with gzio. Additionally, this causes
m5 writefile to fail when checking the error flags for the output
steam.
With this patch we add an additional no_gz argument to
OutputDirectory::create and OutputDirectory::openFile which allows us
to override the gzip compression. Therefore, for m5 writefile we
disable the filename check, and always create a standard ostream.
There's a well-meaning check in Process::allocFD() to return an invalid
target fd (-1) if the incoming host fd is -1. However, this means that
emulated drivers, which want to allocate a target fd that doesn't
correspond to a host fd, can't use -1 to indicate an intentionally
invalid host fd.
It turns out the allocFD() check is redundant, as callers always test
the host fd for validity before calling. Also, callers never test the
return value of allocFD() for validity, so even if the test failed,
it would likely have the undesirable result of returning -1 to the
target app as a file descriptor without setting errno.
Thus the check is pointless and is now getting in the way, so it seems
we should just get rid of it.
The last SimObject using the legacy serialize API with non-const
methods has now been transitioned to the new API. This changeset
removes the serializeOld() methods from the serialization base class
as they are no longer used.
Add functionality to generate a back trace if gem5 crashes (SIGABRT or
SIGSEGV). The current implementation uses glibc's stack traversal
support if available and stubs out the call to print_backtrace()
otherwise.
This patch adds explicit overrides as this is now required when using
"-Wall" with clang >= 3.5, the latter now part of the most recent
XCode. The patch consequently removes "virtual" for those methods
where "override" is added. The latter should be enough of an
indication.
As part of this patch, a few minor issues that clang >= 3.5 complains
about are also resolved (unused methods and variables).
This patch moves away from using M5_ATTR_OVERRIDE and the m5::hashmap
(and similar) abstractions, as these are no longer needed with gcc 4.7
and clang 3.1 as minimum compiler versions.
Trying to run an SE system with varying threads per core (SMT cores + Non-SMT
cores) caused failures due to the CPU id assignment logic. The comment
about thread assignment (worrying about core 0 not having tid 0) seems
not to be valid given that our configuration scripts initialize them in
order.
This removes that constraint so a heterogenously threaded sytem can work.
The recent changeset to readlink() to handle reading the /proc/self/exe link
introduces a number of problems. This patch fixes two:
1) Because readlink() called on /proc/self/exe now uses LiveProcess::progName()
to find the binary path, it will only get the zeroth parameter of the simulated
system command line. However, if a config script also specifies the process'
executable, the executable parameter is used to create the LiveProcess rather
than the zeroth command line parameter. Thus, the zeroth command line parameter
is not necessarily the correct path to the binary executing in the simulated
system. To fix this, add a LiveProcess data member, 'executable', which is
correctly set during instantiation and returned from progName().
2) If a config script allows a user to pass a relative path as the zeroth
simulated system command line parameter or process executable, readlink() will
incorrecly return a relative path when called on '/proc/self/exe'.
/proc/self/exe is always set to a full path, so running benchmarks can fail if
a relative path is returned. To fix this, clean up the handling of
LiveProcess::progName() within readlink() to get the full binary path.
NOTE: This patch still leaves the potential problem that host full path to the
binary bleeds into the simulated system, potentially causing the appearance of
non-deterministic simulated system execution.
This patch fixes a use-after-delete issue in the packet probe points
by adding a PacketInfo struct to retain the key fields before passing
the packet onwards. We want to probe the packet after it is
successfully sent, but by that time the fields may be modified, and
the packet may even be deleted.
Amazingly enough the issue has gone undetected for months, and only
recently popped up in our regressions.
This commit addresses gem5 checkpoints' linear versioning bottleneck.
Since development is distributed across many private trees, there exists
a sort of 'race' for checkpoint version numbers: internally a checkpoint
version may be used but then resynchronizing with the external tree causes
a conflict on that version. This change replaces the linear version number
with a set of unique strings called tags. Now the only conflicts that can
arise are of tag names, where collisions are much easier to avoid.
The checkpoint upgrader (util/cpt_upgrader.py) upgrades the version
representation, as one would expect. Each tag version implements its
upgrader code in a python file in the util/cpt_upgraders directory
rather than adding a function to the upgrader script itself.
The version tags are stored in the 'Globals' section rather than 'root'
(as the version was previously) because 'Globals' gets unserialized
first and can provide a warning before any other unserialization errors
can occur.
This is in support of tag-based checkpoint versioning. It should be
possible to examine an optional parameter in a checkpoint during
unserialization and not have it throw a warning.
Event auto-serialization no longer in use and has been broken ever
since the introduction of PDES support almost two years
ago. Additionally, serializing the individual event queues is
undesirable since it exposes the thread structure of the
simulator. What this means in practice is that the number of threads
in the simulator must be the same when taking a checkpoint and when
loading the checkpoint.
This changeset removes support for the AutoSerialize event flag and
the associated serialization code.
This changeset removes the support for the autoserialize parameter in
GlobalSimLoopExitEvent (including exitSimLoop()) and
LocalSimLoopExitEvent.
Auto-serialization of the LocalSimLoopExitEvent was never used, so
this is not expected to affect anything. However, it was sometimes
used for GlobalSimLoopExitEvent. Unfortunately, serialization of
global events has never been supported, so checkpoints with such
events will currently cause simulation panics.
The serialize parameter to exitSimLoop() has been left in-place to
maintain API compatibility (removing it would affect m5ops). Instead
of just dropping it, we now print a warning if the parameter is set
and the exit event is scheduled in the future (i.e., not at the
current tick).
The object resolver isn't serialization specific and shouldn't live in
serialize.hh. Move it to sim_object.hh since it queries to the
SimObject hierarchy.
