Table policies (i.e., replacement, compression, etc) behave
differently depending on the workload, and it is often desired
to be able to selectively switch between them. In this case
the relevant metadata for all the policies must be added to
all of the entries being analyzed.
In order to avoid having to monitor all table entries, a few
of these entries are selected to be sampled and estimate
overall behavior. These sampled entries belong each to a
single policy. Then, based on the predominance of these
samples, the winning policy is applied to the other sets
(followers).
As of now, in order to avoid having to iterate over a vector,
there is a limited number of dueling instances, but it may be
easily extended, if needed.
Based on Set Dueling, proposed in "Adaptive Insertion Policies
for High Performance Caching".
Change-Id: I692a3e5e0ad98581d68167ad7e6b45ab2f4c7b10
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/37895
Tested-by: kokoro <noreply+kokoro@google.com>
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
With this change, when using a DPRINTF statment on a class inheriting
from the Queue or QueueEntry class, the name at the start of the log
line will be meaningful.
Currently affected classes:
MSHRqueue
MSHR
MSHR::TargetList
WriteQueue
WriteQueueEntry
Change-Id: I4e5ac080fec572961f9f1d9f88429ed6e72d8994
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/47040
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Maintainer: Daniel Carvalho <odanrc@yahoo.com.br>
Tested-by: kokoro <noreply+kokoro@google.com>
The AMPM paper (https://www.jilp.org/vol13/v13paper3.pdf) defines
the bandwidth-delay calculation as :
Mbandwidth= (Nrequests/Tepoch)×Tlatency
In the code, Tepoch and Tlatency are in ticks (which is okay),
but Tepoch is converted from Cycles (256K) to Ticks using the
clockEdge(Cycle c) function, which is incorrect as it yields currentTick
+ c * clockPeriod() instead of just c * clockPeriod().
In other words, the divider keeps increasing as time advances.
This patch substitutes clockEdge() with cyclesToTicks() to keep
the epoch length (Tepoch) constant throughout simulation.
Change-Id: I69dee29892fa4b9eb8de8715fd72a535e122687f
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/46479
Reviewed-by: Nathanael Premillieu <nathanael.premillieu@huawei.com>
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
According to the DPC paper : "If the best score is less
than or equal to a fixed value BADSCORE, we turn prefetchoff
during the next phase"
However, the current code will turn prefetch off if the best
*offset* of the learning phase is less than BADSCORE, which
is incorrect.
Change-Id: Ib5790fe1341f2dd6328ec3b018bc52012e376723
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/46259
Reviewed-by: Nathanael Premillieu <nathanael.premillieu@huawei.com>
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
As part of recent decisions regarding namespace
naming conventions, all namespaces will be changed
to snake case.
::Stats became ::statistics.
"statistics" was chosen over "stats" to avoid generating
conflicts with the already existing variables (there are
way too many "stats" in the codebase), which would make
this patch even more disturbing for the users.
Change-Id: If877b12d7dac356f86e3b3d941bf7558a4fd8719
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/45421
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
As part of recent decisions regarding namespace
naming conventions, all namespaces will be changed
to snake case.
::Prefetcher became ::prefetcher.
"prefetch" was chosen over "prefetcher" to avoid generating
conflicts with the already existing variables. "prefetcher"
is a name that is expected to be more common in user's code
than "prefetch".
Change-Id: I8f07217f278a0229e05545b7847f2620ed208c66
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/45410
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Hoa Nguyen <hoanguyen@ucdavis.edu>
As part of recent decisions regarding namespace
naming conventions, all namespaces will be changed
to snake case.
::Compressor became ::compression.
"compression" was chosen over "compressor" to avoid
generating conflicts with the already existing variables,
as well as because the namespace contains more than solely
compressors (e.g., encoders).
Change-Id: I7054845984784b0dffcc4fb90d66c5096a64194d
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/45406
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
As part of recent decisions regarding namespace
naming conventions, all namespaces will be changed
to snake case.
sim_clock::Int became sim_clock::as_int.
"as_int" was chosen because "int" is a reserved
keyword, and this namespace acts as a selector of
how to read the internal variables.
Another possibility to resolve this would be to
remove the namespaces "Float" and "Int" and use
unions instead.
Change-Id: I65f47608d2212424bed1731c7f53d242d5a7d89a
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/45436
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Hoa Nguyen <hoanguyen@ucdavis.edu>
Maintainer: Gabe Black <gabe.black@gmail.com>
The code in the body of a DPRINTF will always be compiled, even if it's
disabled. If TRACING_ON is false, the if around it will short circuit to
false without actually running any code to check the specified
condition, and the body of the if will be elided by the compiler as
unreachable code.
This creates a more consistent environment whether TRACING_ON is on or
not, so that variables which are only used in DPRINTF don't have to be
guarded by their own TRACING_ON #ifs at the call site. It also ensures
that the code inside DPRINTF is always checked to be valid code, even if
the DPRINTF itself will never go off. This helps avoid syntax errors,
etc, which aren't found because of the configuration of the build being
tested with.
Change-Id: Ia95ae229ebcd2fc9828f62e87f037f76b9279819
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/44988
Maintainer: Gabe Black <gabe.black@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
These were not caught by the previous patches because
the grep used ignored:
- anonymous structures
(e.g., "struct {")
- opening braces without leading spaces
(e.g., "struct Name{"),
- weird chars in auto-generation files
(e.g., "struct $name {").
- extra characters after the opening brace.
(e.g., "struct Name { // Comment")
- typedefs (note that this is not caught by the verifier)
(e.g., "typedef struct Name {")
Most of this has been fixed be grepping structures
with the following regex:
grep -nrE --exclude-dir=systemc \
"^ *(typedef)* *(struct|class|enum|union) [^{]*{$" src/
The following makes sure that "struct{" is captured:
grep -nrE --exclude-dir=systemc \
"^ *(struct|class|enum|union){" src/
To find cases that contain a comment after the
opening brace:
grep -nrE --exclude-dir=systemc \
"^ *(struct|class|enum|union)[^{]*{\s*//" src/
Change-Id: I9f822bed628d13b1a09ccd6059373aff63a8d7bd
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/43505
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>
Tested-by: kokoro <noreply+kokoro@google.com>
The systemc dir was not included in this fix.
First it was identified that there were only occurrences
at 0, 1, and 2 levels of indentation (and 2 of 2 spaces,
1 of 3 spaces and 2 of 12 spaces), using:
grep -nrE --exclude-dir=systemc \
"^ *enum [A-Za-z].* {$" src/
Then the following commands were run to replace:
<indent level>enum X ... {
by:
<indent level>enum X ...
<indent level>{
Level 0:
grep -nrl --exclude-dir=systemc \
"^enum [A-Za-z].* {$" src/ | \
xargs sed -Ei \
's/^enum ([A-Za-z].*) \{$/enum \1\n\{/g'
Level 1:
grep -nrl --exclude-dir=systemc \
"^ enum [A-Za-z].* {$" src/ | \
xargs sed -Ei \
's/^ enum ([A-Za-z].*) \{$/ enum \1\n \{/g'
and so on.
Change-Id: Ib186cf379049098ceaec20dfe4d1edcedd5f940d
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/43326
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Gabe Black <gabe.black@gmail.com>
Maintainer: Giacomo Travaglini <giacomo.travaglini@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
The systemc dir was not included in this fix.
First it was identified that there were only occurrences
at 0, 1, 2 and 3 levels of indentation (and a single
occurrence of 2 and 3 spaces), using:
grep -nrE --exclude-dir=systemc \
"^ *struct [A-Za-z].* {$" src/
Then the following commands were run to replace:
<indent level>struct X ... {
by:
<indent level>struct X ...
<indent level>{
Level 0:
grep -nrl --exclude-dir=systemc
"^struct [A-Za-z].* {$" src/ | \
xargs sed -Ei \
's/^struct ([A-Za-z].*) \{$/struct \1\n\{/g'
Level 1:
grep -nrl --exclude-dir=systemc \
"^ struct [A-Za-z].* {$" src/ | \
xargs sed -Ei \
's/^ struct ([A-Za-z].*) \{$/ struct \1\n \{/g'
and so on.
Change-Id: I362ef58c86912dabdd272c7debb8d25d587cd455
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/39017
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Maintainer: Giacomo Travaglini <giacomo.travaglini@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
The systemc dir was not included in this fix.
First it was identified that there were only occurrences
at 0, 1, and 2 levels of indentation, using:
grep -nrE --exclude-dir=systemc \
"^ *class [A-Za-z].* {$" src/
Then the following commands were run to replace:
<indent level>class X ... {
by:
<indent level>class X ...
<indent level>{
Level 0:
grep -nrl --exclude-dir=systemc
"^class [A-Za-z].* {$" src/ | \
xargs sed -Ei \
's/^class ([A-Za-z].*) \{$/class \1\n\{/g'
Level 1:
grep -nrl --exclude-dir=systemc \
"^ class [A-Za-z].* {$" src/ | \
xargs sed -Ei \
's/^ class ([A-Za-z].*) \{$/ class \1\n \{/g'
and so on.
Change-Id: I17615ce16a333d69867b27c7bae0f4fdafd8b2eb
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/39015
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Maintainer: Giacomo Travaglini <giacomo.travaglini@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
We currently use the traditional SI-like prefixes for to represent
binary multipliers in some contexts. This is ambiguous in many cases
since they overload the meaning of the SI prefix.
Here are some examples of commonly used in the industry:
* Storage vendors define 1 MB as 10**6 bytes
* Memory vendors define 1 MB as 2**20 bytes
* Network equipment treats 1Mbit/s as 10**6 bits/s
* Memory vendors define 1Mbit as 2**20 bits
In practice, this means that a FLASH chip on a storage bus uses
decimal prefixes, but that same flash chip on a memory bus uses binary
prefixes. It would also be reasonable to assume that the contents of a
1Mbit FLASH chip would take 0.1s to transfer over a 10Mbit Ethernet
link. That's however not the case due to different meanings of the
prefix.
The quantity 2MX is treated differently by gem5 depending on the unit
X:
* Physical quantities (s, Hz, V, A, J, K, C, F) use decimal prefixes.
* Interconnect and NoC bandwidths (B/s) use binary prefixes.
* Network bandwidths (bps) use decimal prefixes.
* Memory sizes and storage sizes (B) use binary prefixes.
Mitigate this ambiguity by consistently using the ISO/IEC/SI prefixes
for binary multipliers for parameters and comments where appropriate.
Change-Id: I2d24682d207830f3b7b0ad2ff82b55e082cccb32
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/39576
Reviewed-by: Richard Cooper <richard.cooper@arm.com>
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.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>
The function was defined in a .cc file but marked as inline. gcc seems
to often figure out what it should do, but in clang it doesn't export
the function (since it's marked as inline), and during linking external
references, which don't have a local copy since it's not defined in the
.hh file, will fail.
This failure looks particularly odd because the funciton is virtual,
and so the failure is reported as being unable to compose the vtable
in places where the object is constructed, relatively obscure code
which is generated by the build system and obscured by templates from
an external code base (pybind11).
Change-Id: Ib51aefbf9005e4ca8dfebef32c5def472175f115
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/37436
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
