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author | Daniel R. Carvalho <odanrc@yahoo.com.br> | 2018-02-19 15:13:11 +0100 |
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committer | Daniel Carvalho <odanrc@yahoo.com.br> | 2018-03-22 14:50:23 +0000 |
commit | d207e9ccee411877fdeac80bb68a27900560f50f (patch) | |
tree | 120810cf72c52ed5df29436552e06f1fb11aa5ce /src/mem/cache/replacement_policies/ReplacementPolicies.py | |
parent | 0473286ab1e9992a906eff380000bf90c82eeccb (diff) | |
download | gem5-d207e9ccee411877fdeac80bb68a27900560f50f.tar.xz |
mem-cache: Split array indexing and replacement policies.
Replacement policies (LRU, Random) are currently considered as array
indexing methods, but have completely different functionalities:
- Array indexers determine the possible locations for block allocation.
This information is used to generate replacement candidates when
conflicts happen.
- Replacement policies determine which of the replacement candidates
should be evicted to make room for new allocations.
For this reason, they were split into different classes. Advantages:
- Easier and more straightforward to implement other replacement
policies (RRIP, LFU, ARC, ...)
- Allow easier future implementation of cache organization schemes
As now we can't assure the use of sets, the previous way to create a
true LRU is not viable. Now a timestamp_bits parameter controls how
many bits are dedicated for the timestamp, and a true LRU can be
achieved through an infinite number of bits (although a few bits suffice
in practice).
Change-Id: I23750db121f1474d17831137e6ff618beb2b3eda
Reviewed-on: https://gem5-review.googlesource.com/8501
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Diffstat (limited to 'src/mem/cache/replacement_policies/ReplacementPolicies.py')
-rw-r--r-- | src/mem/cache/replacement_policies/ReplacementPolicies.py | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/src/mem/cache/replacement_policies/ReplacementPolicies.py b/src/mem/cache/replacement_policies/ReplacementPolicies.py new file mode 100644 index 000000000..64743819b --- /dev/null +++ b/src/mem/cache/replacement_policies/ReplacementPolicies.py @@ -0,0 +1,46 @@ +# Copyright (c) 2018 Inria +# All rights reserved. +# +# Redistribution and use in source and binary forms, with or without +# modification, are permitted provided that the following conditions are +# met: redistributions of source code must retain the above copyright +# notice, this list of conditions and the following disclaimer; +# redistributions in binary form must reproduce the above copyright +# notice, this list of conditions and the following disclaimer in the +# documentation and/or other materials provided with the distribution; +# neither the name of the copyright holders nor the names of its +# contributors may be used to endorse or promote products derived from +# this software without specific prior written permission. +# +# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. +# +# Authors: Daniel Carvalho + +from m5.params import * +from m5.proxy import * +from m5.SimObject import SimObject + +class BaseReplacementPolicy(SimObject): + type = 'BaseReplacementPolicy' + abstract = True + cxx_header = "mem/cache/replacement_policies/base.hh" + +class LRURP(BaseReplacementPolicy): + type = 'LRURP' + cxx_class = 'LRURP' + cxx_header = "mem/cache/replacement_policies/lru_rp.hh" + +class RandomRP(BaseReplacementPolicy): + type = 'RandomRP' + cxx_class = 'RandomRP' + cxx_header = "mem/cache/replacement_policies/random_rp.hh" |