brrip_rp.cc (12626:e161d7725d4b) | brrip_rp.cc (12684:44ebd2bc020f) |
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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; --- 16 unchanged lines hidden (view full) --- 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/brrip_rp.hh" 32 | 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; --- 16 unchanged lines hidden (view full) --- 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/brrip_rp.hh" 32 |
33#include <memory> 34 35#include "base/logging.hh" // For fatal_if |
|
33#include "base/random.hh" | 36#include "base/random.hh" |
34#include "debug/CacheRepl.hh" | |
35 36BRRIPRP::BRRIPRP(const Params *p) 37 : BaseReplacementPolicy(p), 38 maxRRPV(p->max_RRPV), hitPriority(p->hit_priority), btp(p->btp) 39{ | 37 38BRRIPRP::BRRIPRP(const Params *p) 39 : BaseReplacementPolicy(p), 40 maxRRPV(p->max_RRPV), hitPriority(p->hit_priority), btp(p->btp) 41{ |
40 if (maxRRPV == 0){ 41 fatal("max_RRPV should be greater than zero.\n"); 42 } | 42 fatal_if(maxRRPV <= 0, "max_RRPV should be greater than zero.\n"); |
43} 44 45void | 43} 44 45void |
46BRRIPRP::touch(CacheBlk *blk) | 46BRRIPRP::invalidate(const std::shared_ptr<ReplacementData>& replacement_data) 47const |
47{ | 48{ |
48 BaseReplacementPolicy::touch(blk); | 49 std::shared_ptr<BRRIPReplData> casted_replacement_data = 50 std::static_pointer_cast<BRRIPReplData>(replacement_data); |
49 | 51 |
52 // Set RRPV to an invalid distance 53 casted_replacement_data->rrpv = maxRRPV + 1; 54} 55 56void 57BRRIPRP::touch(const std::shared_ptr<ReplacementData>& replacement_data) const 58{ 59 std::shared_ptr<BRRIPReplData> casted_replacement_data = 60 std::static_pointer_cast<BRRIPReplData>(replacement_data); 61 |
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50 // Update RRPV if not 0 yet | 62 // Update RRPV if not 0 yet |
51 // Every hit in HP mode makes the block the last to be evicted, while 52 // in FP mode a hit makes the block less likely to be evicted | 63 // Every hit in HP mode makes the entry the last to be evicted, while 64 // in FP mode a hit makes the entry less likely to be evicted |
53 if (hitPriority) { | 65 if (hitPriority) { |
54 blk->rrpv = 0; 55 } else if (blk->rrpv > 0) { 56 blk->rrpv--; | 66 casted_replacement_data->rrpv = 0; 67 } else if (casted_replacement_data->rrpv > 0) { 68 casted_replacement_data->rrpv--; |
57 } 58} 59 60void | 69 } 70} 71 72void |
61BRRIPRP::reset(CacheBlk *blk) | 73BRRIPRP::reset(const std::shared_ptr<ReplacementData>& replacement_data) const |
62{ | 74{ |
63 BaseReplacementPolicy::reset(blk); | 75 std::shared_ptr<BRRIPReplData> casted_replacement_data = 76 std::static_pointer_cast<BRRIPReplData>(replacement_data); |
64 65 // Reset RRPV | 77 78 // Reset RRPV |
66 // Blocks are inserted as "long re-reference" if lower than btp, | 79 // Replacement data is inserted as "long re-reference" if lower than btp, |
67 // "distant re-reference" otherwise 68 if (random_mt.random<unsigned>(1, 100) <= btp) { | 80 // "distant re-reference" otherwise 81 if (random_mt.random<unsigned>(1, 100) <= btp) { |
69 blk->rrpv = maxRRPV-1; | 82 casted_replacement_data->rrpv = maxRRPV-1; |
70 } else { | 83 } else { |
71 blk->rrpv = maxRRPV; | 84 casted_replacement_data->rrpv = maxRRPV; |
72 } 73} 74 | 85 } 86} 87 |
75CacheBlk* 76BRRIPRP::getVictim(const ReplacementCandidates& candidates) | 88ReplaceableEntry* 89BRRIPRP::getVictim(const ReplacementCandidates& candidates) const |
77{ 78 // There must be at least one replacement candidate 79 assert(candidates.size() > 0); 80 | 90{ 91 // There must be at least one replacement candidate 92 assert(candidates.size() > 0); 93 |
81 // Use visitor to search for the victim 82 CacheBlk* blk = candidates[0]; | 94 // Use first candidate as dummy victim 95 ReplaceableEntry* victim = candidates[0]; 96 97 // Store victim->rrpv in a variable to improve code readability 98 int victim_RRPV = std::static_pointer_cast<BRRIPReplData>( 99 victim->replacementData)->rrpv; 100 101 // Visit all candidates to find victim |
83 for (const auto& candidate : candidates) { | 102 for (const auto& candidate : candidates) { |
84 // Stop iteration if found an invalid block 85 if (!candidate->isValid()) { 86 blk = candidate; 87 blk->rrpv = maxRRPV; 88 break; 89 // Update victim block if necessary 90 } else if (candidate->rrpv > blk->rrpv) { 91 blk = candidate; | 103 // Get candidate's rrpv 104 int candidate_RRPV = std::static_pointer_cast<BRRIPReplData>( 105 candidate->replacementData)->rrpv; 106 107 // Stop searching for victims if an invalid entry is found 108 if (candidate_RRPV == maxRRPV + 1) { 109 return candidate; 110 // Update victim entry if necessary 111 } else if (candidate_RRPV > victim_RRPV) { 112 victim = candidate; 113 victim_RRPV = candidate_RRPV; |
92 } 93 } 94 | 114 } 115 } 116 |
95 // Make sure we don't have an invalid rrpv 96 assert(blk->rrpv <= maxRRPV); | 117 // Get difference of victim's RRPV to the highest possible RRPV in 118 // order to update the RRPV of all the other entries accordingly 119 int diff = maxRRPV - victim_RRPV; |
97 | 120 |
98 // Get difference of block's RRPV to the highest possible RRPV in 99 // order to update the RRPV of all the other blocks accordingly 100 unsigned diff = maxRRPV - blk->rrpv; 101 | |
102 // No need to update RRPV if there is no difference 103 if (diff > 0){ 104 // Update RRPV of all candidates 105 for (const auto& candidate : candidates) { | 121 // No need to update RRPV if there is no difference 122 if (diff > 0){ 123 // Update RRPV of all candidates 124 for (const auto& candidate : candidates) { |
106 // Update the block's RPPV with the new value 107 candidate->rrpv += diff; | 125 std::static_pointer_cast<BRRIPReplData>( 126 candidate->replacementData)->rrpv += diff; |
108 } 109 } 110 | 127 } 128 } 129 |
111 DPRINTF(CacheRepl, "set %x, way %x: selecting blk for replacement\n", 112 blk->set, blk->way); | 130 return victim; 131} |
113 | 132 |
114 return blk; | 133std::shared_ptr<ReplacementData> 134BRRIPRP::instantiateEntry() 135{ 136 return std::shared_ptr<ReplacementData>(new BRRIPReplData(maxRRPV)); |
115} 116 117BRRIPRP* 118BRRIPRPParams::create() 119{ 120 return new BRRIPRP(this); 121} | 137} 138 139BRRIPRP* 140BRRIPRPParams::create() 141{ 142 return new BRRIPRP(this); 143} |