summaryrefslogtreecommitdiff
path: root/src/mem
diff options
context:
space:
mode:
authorDaniel R. Carvalho <odanrc@yahoo.com.br>2018-03-09 16:44:23 +0100
committerDaniel Carvalho <odanrc@yahoo.com.br>2018-03-30 18:38:17 +0000
commitc2d03ba24f52aec96bf569309a59022e0d4e3c21 (patch)
tree2cf87a19c6ba796bca4ec1297595b02b4f57e63d /src/mem
parent2b5245bdd8b6cb11462a37528cfe0d6e637aacff (diff)
downloadgem5-c2d03ba24f52aec96bf569309a59022e0d4e3c21.tar.xz
mem-cache: Create LFU replacement policy
Implementation of a Least Frequently Used replacement policy. Change-Id: I772afccd3a7955777e53d59341e922718db44e5c Reviewed-on: https://gem5-review.googlesource.com/8890 Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com> Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Diffstat (limited to 'src/mem')
-rw-r--r--src/mem/cache/replacement_policies/ReplacementPolicies.py5
-rw-r--r--src/mem/cache/replacement_policies/SConscript1
-rw-r--r--src/mem/cache/replacement_policies/lfu_rp.cc69
-rw-r--r--src/mem/cache/replacement_policies/lfu_rp.hh70
4 files changed, 145 insertions, 0 deletions
diff --git a/src/mem/cache/replacement_policies/ReplacementPolicies.py b/src/mem/cache/replacement_policies/ReplacementPolicies.py
index 5f7ecfc5c..0beb3e60f 100644
--- a/src/mem/cache/replacement_policies/ReplacementPolicies.py
+++ b/src/mem/cache/replacement_policies/ReplacementPolicies.py
@@ -40,6 +40,11 @@ class FIFORP(BaseReplacementPolicy):
cxx_class = 'FIFORP'
cxx_header = "mem/cache/replacement_policies/fifo_rp.hh"
+class LFURP(BaseReplacementPolicy):
+ type = 'LFURP'
+ cxx_class = 'LFURP'
+ cxx_header = "mem/cache/replacement_policies/lfu_rp.hh"
+
class LRURP(BaseReplacementPolicy):
type = 'LRURP'
cxx_class = 'LRURP'
diff --git a/src/mem/cache/replacement_policies/SConscript b/src/mem/cache/replacement_policies/SConscript
index 4ac8fe8e6..26c450a79 100644
--- a/src/mem/cache/replacement_policies/SConscript
+++ b/src/mem/cache/replacement_policies/SConscript
@@ -35,6 +35,7 @@ SimObject('ReplacementPolicies.py')
Source('base.cc')
Source('brrip_rp.cc')
Source('fifo_rp.cc')
+Source('lfu_rp.cc')
Source('lru_rp.cc')
Source('mru_rp.cc')
Source('random_rp.cc')
diff --git a/src/mem/cache/replacement_policies/lfu_rp.cc b/src/mem/cache/replacement_policies/lfu_rp.cc
new file mode 100644
index 000000000..90a5ee227
--- /dev/null
+++ b/src/mem/cache/replacement_policies/lfu_rp.cc
@@ -0,0 +1,69 @@
+/**
+ * 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
+ */
+
+#include "mem/cache/replacement_policies/lfu_rp.hh"
+
+#include "debug/CacheRepl.hh"
+
+LFURP::LFURP(const Params *p)
+ : BaseReplacementPolicy(p)
+{
+}
+
+CacheBlk*
+LFURP::getVictim(const ReplacementCandidates& candidates)
+{
+ // There must be at least one replacement candidate
+ assert(candidates.size() > 0);
+
+ // Visit all candidates to find victim
+ CacheBlk* blk = candidates[0];
+ for (const auto& candidate : candidates) {
+ // Stop iteration if found an invalid block
+ if (!candidate->isValid()) {
+ blk = candidate;
+ break;
+ // Update victim block if necessary
+ } else if (candidate->refCount < blk->refCount) {
+ blk = candidate;
+ }
+ }
+
+ DPRINTF(CacheRepl, "set %x, way %x: selecting blk for replacement\n",
+ blk->set, blk->way);
+
+ return blk;
+}
+
+LFURP*
+LFURPParams::create()
+{
+ return new LFURP(this);
+}
diff --git a/src/mem/cache/replacement_policies/lfu_rp.hh b/src/mem/cache/replacement_policies/lfu_rp.hh
new file mode 100644
index 000000000..affc849a2
--- /dev/null
+++ b/src/mem/cache/replacement_policies/lfu_rp.hh
@@ -0,0 +1,70 @@
+/**
+ * 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
+ */
+
+/**
+ * @file
+ * Declaration of a Least Frequently Used replacement policy.
+ * The victim is chosen using the reference frequency. The least referenced
+ * block is always chosen to be evicted, regardless of the amount of times
+ * it has been touched, or how long has passed since its last touch.
+ */
+
+#ifndef __MEM_CACHE_REPLACEMENT_POLICIES_LFU_RP_HH__
+#define __MEM_CACHE_REPLACEMENT_POLICIES_LFU_RP_HH__
+
+#include "mem/cache/replacement_policies/base.hh"
+#include "params/LFURP.hh"
+
+class LFURP : public BaseReplacementPolicy
+{
+ public:
+ /** Convenience typedef. */
+ typedef LFURPParams Params;
+
+ /**
+ * Construct and initiliaze this replacement policy.
+ */
+ LFURP(const Params *p);
+
+ /**
+ * Destructor.
+ */
+ ~LFURP() {}
+
+ /**
+ * Find replacement victim using reference frequency.
+ *
+ * @param cands Replacement candidates, selected by indexing policy.
+ * @return Cache block to be replaced.
+ */
+ CacheBlk* getVictim(const ReplacementCandidates& candidates) override;
+};
+
+#endif // __MEM_CACHE_REPLACEMENT_POLICIES_LFU_RP_HH__