| /** |
| * 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/random_rp.hh" |
| |
| #include "base/random.hh" |
| #include "debug/CacheRepl.hh" |
| |
| RandomRP::RandomRP(const Params *p) |
| : BaseReplacementPolicy(p) |
| { |
| } |
| |
| CacheBlk* |
| RandomRP::getVictim(const ReplacementCandidates& candidates) |
| { |
| // There must be at least one replacement candidate |
| assert(candidates.size() > 0); |
| |
| // Choose one candidate at random |
| CacheBlk* blk = candidates[random_mt.random<unsigned>(0, |
| candidates.size() - 1)]; |
| |
| // Visit all candidates to find an invalid entry |
| for (const auto& candidate : candidates) { |
| // Give priority to victimise invalid entries |
| if (!candidate->isValid()){ |
| blk = candidate; |
| break; |
| } |
| } |
| |
| // If no invalid blocks were found, choose one of the candidates randomly |
| DPRINTF(CacheRepl, "set %x, way %x: selecting blk for replacement\n", |
| blk->set, blk->way); |
| |
| return blk; |
| } |
| |
| RandomRP* |
| RandomRPParams::create() |
| { |
| return new RandomRP(this); |
| } |