This class had been trying to keep all indices within the modulus of the
queue size, and to use all elements in the underlying storage by making
the empty and full conditions alias, differentiated by a bool. To keep
track of the difference between a storage location on one trip around
the queue vs other times around, ie an alias once the indices had
wrapped, it also keep track of a "round" value in both the queue itself,
and any iterators it created.
All this bookkeeping significantly complicated the data structure.
Instead, this change modifies it to keep track of a monotonically
increasing index which is wrapped at the time it's used. Only the head
index and current size need to be tracked in the queue itself, and only
a pointer to the queue and an index need to be tracked in the iterators.
Theoretically, it's possible that this value could overflow eventually
since it increases forever, unlike before where the index wrapped and
was never larger than the queue's capacity. In practice, the type of the
index was changed from a uint32_t to a size_t, probably a 64 bit value
in modern systems, which will hold much larger values. Also, the round
counter and the index values together acted like a smaller than 64 bit
value anyway, since the round counter would overflow after 2^32 times
around a less than 2^32 entry queue.
One minor interface difference is that the head() and tail() values
returned by the queue are no longer pre-wrapped to be modulo the queue's
capacity. As long as consumers don't try to be overly clever and feed in
fixed values, do their own bounds checking, etc., something that would
be cumbersome considering the wrapping nature of the structure, this
shouldn't be an issue.
Also, since external consumers no longer need to worry about wrapping,
since only one of them was used in only one place, and because they
weren't even marked as part of the interface, the modulo helper
functions have been eliminated from the queue. If other code wants to
perform modulo arithmetic for some reason (which the queue no longer
requires) they can accomplish basically the same thing in basically the
same amount of code using normal math.
Also, rather than inherit from std::vector, this change makes the vector
internal to the queue. That prevents methods of the vector that aren't
aware of the circular nature of the structure from leaking out if
they're not overridden or otherwise proactively blocked.
On top of simplifying the implementation, this also makes it perform
*slightly* better. To measure that, I ran the following command:
$ time build/ARM/base/circular_queue.test.opt --gtest_repeat=100000 > /dev/null
and found a few percent improvement in total run time. While this
difference was small and not measured against realistic usage of the
data structure, it was still measurable, and at minimum doesn't seem to
have hurt performance.
Change-Id: Ic2baa28de135be7086fa94579bbec451d69b3b15
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/38478
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Maintainer: Gabe Black <gabe.black@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
This commit makes move stats from several classes in mem/ruby
to corresponding Stats::Group's.
For ruby's Profiler, additional changes are made: there are stats that
are profiled for each of RequestType, for each of MachineType, and for
each of combinations of RequestType and MachineType. The current naming
scheme is ...<stat_name>.<request_type_name>.<machine_type_name>. To make
it easier for stats parser to know whether the stat is of RequestType, or
is of MachineType, or is of (RequestType, MachineType), a prefix is added
as follows,
...<meta>.<stat_name>.<request_type_name>.<machine_type_name>
where <meta> is one of {RequestType, MachineType, RequestTypeMachineType}.
Another point of using this naming scheme is that the parser doesn't
need to know all of RequestType and MachineType.
Change-Id: I8b8bdd771c7798954f984d416f521e8eb42d01ed
Signed-off-by: Hoa Nguyen <hoanguyen@ucdavis.edu>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/36478
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Currently, there are some accounts that cannot be added as a
reviewer due to unknown conflicts associated with the email address.
This commit adds the ability for the bot to use
ReviewerInfo._account_id when possible, and to use email addresses
otherwise.
To reduce the number of queries to the server, a json file will be
created in .data/ to store known account ID's.
Change-Id: I9887bec12d14279e61119a615687a339e3f9c994
Signed-off-by: Hoa Nguyen <hoanguyen@ucdavis.edu>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/38236
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
SimObject outputs a warning when its parent is specified more than
once. The cause is most likely that there is unexpected param
specified in the constructor called in the Python interface.
This commit adds a note about this probable cause of this potential
error to the warning message.
Change-Id: I9b6bf5d5fb0c77bfdad5fde42e88f814e8a4b72b
Signed-off-by: Hoa Nguyen <hoanguyen@ucdavis.edu>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/38359
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
These allow you to set the target physical address, and map or unmap the
region of physical memory. This is not automatic for two reasons. First,
the address needs to be configured before the mapping is done, and
there's no way to ensure that ordering when everything is handled
automatically. Second, if the user isn't going to use the address based
mechanism, then the mapping and access to /dev/mem isn't necessary and
may prevent using the other call types.
Change-Id: I0f9c32d6bfa402ba59ea1bf5672fb7f11003568d
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/28184
Reviewed-by: Gabe Black <gabe.black@gmail.com>
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>
Tested-by: kokoro <noreply+kokoro@google.com>
This makes it easier to manage the java wrapper since there's only one
file. This change also splits up the command builder which builds the
java jar since we need to run one step which produces the .h, then a
second step to build the library, and then finally the step that
produces the jar. The first step is left as a command builder since the
scons Java builder still doesn't know about the -h option, but the
second step now uses the Jar builder.
Change-Id: I76e2e5e86bb3153f2ba69a75ad94cd4e065cd33d
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/28183
Reviewed-by: Gabe Black <gabe.black@gmail.com>
Maintainer: Gabe Black <gabe.black@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Convert the native implementation from C to C++. Also expand the test to
cycle through the different call mechanisms and call "sum" using each
one. This test should primarily be run on a gem5 native CPU which will
support all call types.
To access a particular call type, get an instance of the gem5.Ops class
from the callTypes static map, using the name of the call type you want
as the key. If you just want whatever the default is, use the additional
key "default".
Change-Id: If4ef812c9746fbf974e54cc9fe515e2b581e9939
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/28182
Reviewed-by: Gabe Black <gabe.black@gmail.com>
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Maintainer: Gabe Black <gabe.black@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
To limit the number of license slots used by SCons when building fast
model components, the fastmodel SConscript set up a group of nodes
which are attached to each simgen run using the SCons SideEffect
method using one of the library files it generates.
To create each unique node, the SCons Value() method was used, passing
it the counter for the loop. In at least version 4 of SCons, what this
ended up doing was setting that library file as a source for each of
the Value() nodes it corresponds to.
That doesn't *seem* like a problem, but then when creating config
include files, files which expose SCons configuration values to C++,
they also create Value() nodes using the value of the config variable.
In cases where that variable is boolean, the value might be 0 or 1.
The result was that the config header depended on Value(0) (for
instance), and then Value(0) depended on a collection of static library
files.
When scons tried to determine whether the config file was up to date,
it tried to check if if its sources had changed. It would check
Value(0), and then Value(0) would try to compute a checksum for its own
source. To do that, it seems to assume that the value can be
interpreted as a string and tries to decode it as utf8. Since the
library is a binary file, that would fail and break the build with a
cryptic message from within the guts of SCons.
To address this, this change replaces the loop index with a call to
object(). Each instance created in that way will be different from
every other, and there will be no way (purposefully or otherwise) to
create a collision with it when creating Value() nodes for some other
purpose.
Change-Id: I56bc842ae66b8cb36d3dcbc25796b708254d6982
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/38617
Reviewed-by: Yu-hsin Wang <yuhsingw@google.com>
Reviewed-by: Ahbong Chang <cwahbong@google.com>
Maintainer: Gabe Black <gabe.black@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
SCons has a system of "tools", which basically detect versions of build
tools (compilers, linkers, etc) and set up an environment with the
appropriate build variable substitutions for that tool to be used.
For instance, there would be a "tool" for gcc, and it would detect if
gcc is present on the system, and if so would set the "CC" variable to
"gcc". An actually tool as defined by SCons would be a lot more
sophisticated than that and set more variables, but that's the basic
idea.
To help modularize the gem5 SConstruct file, I moved code which would
set up git commit hooks into a "tool" which helped modularize it and
reduce the size of SConstruct.
This isn't quite right since, while the code does detect if git was
used to check out the source (if there is a .git file at the root), it
doesn't really modify the environment at all. It will also be invoked
every time any environment is set up, although right now that will only
be the DefaultEnvironment, what's used when loose functions like
Builder or Command are called with, and the "main" environment which
all the others are Clone-d from.
Normally, when SCons sets up a new environment, either implicitly or
when Environment() is called, it sets up a bunch of built in tools
which are fixed within SCons itself. If you want, you can add a "tools"
argument to Environment (or to the DefaultEnvironment() function) which
will replace that list of tools. That can be used to make an
environment use the new "git" tool, but it isn't automatic.
SCons also lets you override default tools by creating your own with
the same name as the default. To make loading the git tool automatic,
I added an override "default" tool which, in addition to setting some
defaults which should apply to all environments, also pulled in other
tools, at that time "git" and "mercurial" (RIP).
Unfortunately, that meant that today, apparently particularly with
SCons version 4, *any* Environment would pull in "git", and all of
"git"'s dependencies, even if SCons wasn't set up enough for those to
work.
To break that dependency, this change stops the default tool from
automatically loading the git tool, although it does continue to set
other defaults which have very minimal external dependencies. When
creating the "main" Environment in the SConstruct, the "git" tool is
now added in explicitly. Since the list of tools replaces the original
and doesn't extend it, we have to add in "default" explicitly as well.
Really, the "git" tool should be converted from the tool interface into
something more appropriate, like perhaps a small module under
site_scons which site_init.py can import and call. When that happens,
main can be declared like normal again.
While making this change, I also got rid of a few nonstandard additions
to the main environment that were little used and not really necessary.
When reading the SConstruct, it wasn't very obvious where those extra
values were coming from, and they didn't really add any value.
Change-Id: I574db42fc2196bf62fc13d6754357c753ceb9117
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/38616
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Reviewed-by: Yu-hsin Wang <yuhsingw@google.com>
Maintainer: Gabe Black <gabe.black@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
These values were (seemingly) arbitrarily changed from the original,
non-KVM settings, and no longer matched the comments which were also
copied over. These two bits enable alignment checking on memory accesses
(not normally used on x86), and whether kernel code can write to read
only pages.
Change-Id: I48e560e448e4849607f12e9336d1ab0458ad9407
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/38536
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Implementation of a generic frequency-based sampling
compressor. The compressor goes through a sampling stage,
where no compression is done, and the values are simply
sampled for their frequencies. Then, after enough samples
have been taken, the compressor starts generating
compressed data.
Compression works by comparing chunks to the table of
most frequent values. In theory, a chunk that is present
in the frequency table has its value replaced by the
index of its respective entry in the table. In practice,
the value itself is stored because there is no straight-
forward way to acquire an index from an entry.
Finally, the index can be encoded so that the values
with highest frequency have smaller codeword representation.
Its Huffman coupling can be used similar to the approach
taken in "SC 2 : A Statistical Compression Cache Scheme".
Change-Id: Iae0ebda08e8c08f3b62930fd0fb7e818fd0d141f
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/37335
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
For some segments, there are two base registers. One is the
architecturally visible base, and the other is the effective base used
when actually referencing memory relative to that segment. The process
initialization code was setting the architecturally visible base,
presumably because that's the value used by KVM, but was setting the
effective base to zero.
Change-Id: I06e079f24fa63f0051268437bf00c14578f62612
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/38488
Reviewed-by: Gabe Black <gabe.black@gmail.com>
Maintainer: Gabe Black <gabe.black@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
When a gem5 op is triggered using a KVM MMIO exit event, the PC has
already been advanced beyond the offending instruction. Normally when
a system call or gem5 op is triggered, the PC has not advanced because
the instruction hasn't actually finished executing. This means that if
a gem5 op, and by extension a system call in SE mode, want to advance
the PC to the instruction after the gem5 op, they have to check whether
they were triggered from KVM.
To avoid having to special case these sorts of situations (currently
only in the clone system call), we can have the code which dispatches to
gem5 ops from KVM adjust the next PC so that it points to what the
current PC is. That way the PC can be advanced unconditionally, and will
point to the instruction after the one that triggered the call.
To be fully consistent, we would also need to adjust the current PC.
That would be non-trivial since we'd have to figure out where the
current instruction started, and that may not even be possible to
unambiguously determine given x86's instruction structure. Then we would
also need to restore the original PC to avoid confusing KVM.
Change-Id: I9ef90b2df8e27334dedc25c59eb45757f7220eea
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/38486
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
These pseudo insts are less useful outside of full system, but they
should all still work. Removing this check makes it possible to, for
instance, test them in syscall emulation mode, and removes another
difference between the two styles of simulation.
Change-Id: Ia7d29bfc6f7c5c236045d151930fc171a6966799
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/38485
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Maintainer: Giacomo Travaglini <giacomo.travaglini@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
This is the official scons way to check for things on the system. This
adds two custom checks, one for java packages and one for pkg-config
packages. This change also adds a check for the org.junit java package
which is/will be used for a test for the java wrapper.
Change-Id: I59ca559f257a4c671e9b72a50b5635b5eb61ee69
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/28180
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Maintainer: Gabe Black <gabe.black@gmail.com>
Installing the term utility within the host filesystem is an unlikely
scenario. Most times, the utility will be used in place or trivially
copied to a local directory within the PATH.
Furthermore, the install target hardcoded a privileged installation,
which is a non-standard and insecure technique.
Change-Id: I1592a304017c6b24a9421aa353229fb5a5baae43
Signed-off-by: Adrian Herrera <adrian.herrera@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/38415
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
