1/** 2 * Copyright (c) 2018 Inria 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are 7 * met: redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer; 9 * redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution; 12 * neither the name of the copyright holders nor the names of its 13 * contributors may be used to endorse or promote products derived from 14 * this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 * 28 * Authors: Daniel Carvalho 29 */ 30 31#include "mem/cache/replacement_policies/random_rp.hh" 32 33#include "base/random.hh"
| 1/** 2 * Copyright (c) 2018 Inria 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are 7 * met: redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer; 9 * redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution; 12 * neither the name of the copyright holders nor the names of its 13 * contributors may be used to endorse or promote products derived from 14 * this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 * 28 * Authors: Daniel Carvalho 29 */ 30 31#include "mem/cache/replacement_policies/random_rp.hh" 32 33#include "base/random.hh"
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34#include "debug/CacheRepl.hh"
| 34#include "mem/cache/blk.hh"
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35 36RandomRP::RandomRP(const Params *p) 37 : BaseReplacementPolicy(p) 38{ 39} 40
| 35 36RandomRP::RandomRP(const Params *p) 37 : BaseReplacementPolicy(p) 38{ 39} 40
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41CacheBlk* 42RandomRP::getVictim(const ReplacementCandidates& candidates)
| 41void 42RandomRP::invalidate(const std::shared_ptr<ReplacementData>& replacement_data) 43const
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43{
| 44{
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| 45 // Unprioritize replacement data victimization 46 std::static_pointer_cast<RandomReplData>( 47 replacement_data)->valid = false; 48} 49 50void 51RandomRP::touch(const std::shared_ptr<ReplacementData>& replacement_data) const 52{ 53} 54 55void 56RandomRP::reset(const std::shared_ptr<ReplacementData>& replacement_data) const 57{ 58 // Unprioritize replacement data victimization 59 std::static_pointer_cast<RandomReplData>( 60 replacement_data)->valid = true; 61} 62 63ReplaceableEntry* 64RandomRP::getVictim(const ReplacementCandidates& candidates) const 65{
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44 // There must be at least one replacement candidate 45 assert(candidates.size() > 0); 46 47 // Choose one candidate at random
| 66 // There must be at least one replacement candidate 67 assert(candidates.size() > 0); 68 69 // Choose one candidate at random
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48 CacheBlk* blk = candidates[random_mt.random<unsigned>(0,
| 70 ReplaceableEntry* victim = candidates[random_mt.random<unsigned>(0,
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49 candidates.size() - 1)]; 50
| 71 candidates.size() - 1)]; 72
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51 // Visit all candidates to find an invalid entry
| 73 // Visit all candidates to search for an invalid entry. If one is found, 74 // its eviction is prioritized
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52 for (const auto& candidate : candidates) {
| 75 for (const auto& candidate : candidates) {
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53 // Give priority to victimise invalid entries 54 if (!candidate->isValid()){ 55 blk = candidate;
| 76 if (!std::static_pointer_cast<RandomReplData>( 77 candidate->replacementData)->valid) { 78 victim = candidate;
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56 break; 57 } 58 } 59
| 79 break; 80 } 81 } 82
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60 // If no invalid blocks were found, choose one of the candidates randomly 61 DPRINTF(CacheRepl, "set %x, way %x: selecting blk for replacement\n", 62 blk->set, blk->way);
| 83 return victim; 84}
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63
| 85
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64 return blk;
| 86std::shared_ptr<ReplacementData> 87RandomRP::instantiateEntry() 88{ 89 return std::shared_ptr<ReplacementData>(new ReplacementData());
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65} 66 67RandomRP* 68RandomRPParams::create() 69{ 70 return new RandomRP(this); 71}
| 90} 91 92RandomRP* 93RandomRPParams::create() 94{ 95 return new RandomRP(this); 96}
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