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Diffstat (limited to 'src/mem/cache/tags/iic_repl/gen.cc')
| -rw-r--r-- | src/mem/cache/tags/iic_repl/gen.cc | 246 |
1 files changed, 246 insertions, 0 deletions
diff --git a/src/mem/cache/tags/iic_repl/gen.cc b/src/mem/cache/tags/iic_repl/gen.cc new file mode 100644 index 000000000..bc4e6b86a --- /dev/null +++ b/src/mem/cache/tags/iic_repl/gen.cc @@ -0,0 +1,246 @@ +/* + * Copyright (c) 2002-2005 The Regents of The University of Michigan + * 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: Erik Hallnor + * Steve Reinhardt + */ + +/** + * @file + * Definitions of the Generational replacement policy. + */ + +#include <string> + +#include "base/misc.hh" +#include "mem/cache/tags/iic.hh" +#include "mem/cache/tags/repl/gen.hh" +#include "params/GenRepl.hh" +#include "sim/host.hh" + +using namespace std; + +GenRepl::GenRepl(const Params *p) // fix this, should be set by cache + : Repl(p), num_pools(p->num_pools), fresh_res(p->fresh_res), + pool_res(p->pool_res), num_entries(0), num_pool_entries(0), misses(0), + pools(pools = new GenPool[num_pools+1]) +{ +} + +GenRepl::~GenRepl() +{ + delete [] pools; +} + +unsigned long +GenRepl::getRepl() +{ + unsigned long tmp; + GenReplEntry *re; + int i; + int num_seen = 0; + if (!(num_pool_entries>0)) { + fatal("No blks available to replace"); + } + num_entries--; + num_pool_entries--; + for (i = 0; i < num_pools; i++) { + while ((re = pools[i].pop())) { + num_seen++; + // Remove invalidated entries + if (!re->valid) { + delete re; + continue; + } + if (iic->clearRef(re->tag_ptr)) { + pools[(((i+1)== num_pools)? i :i+1)].push(re, misses); + } + else { + tmp = re->tag_ptr; + delete re; + + repl_pool.sample(i); + + return tmp; + } + } + } + fatal("No replacement found"); + return 0xffffffff; +} + +unsigned long * +GenRepl::getNRepl(int n) +{ + unsigned long *tmp; + GenReplEntry *re; + int i; + if (!(num_pool_entries>(n-1))) { + fatal("Not enough blks available to replace"); + } + num_entries -= n; + num_pool_entries -= n; + tmp = new unsigned long[n]; /* array of cache_blk pointers */ + int blk_index = 0; + for (i = 0; i < num_pools && blk_index < n; i++) { + while (blk_index < n && (re = pools[i].pop())) { + // Remove invalidated entries + if (!re->valid) { + delete re; + continue; + } + if (iic->clearRef(re->tag_ptr)) { + pools[(((i+1)== num_pools)? i :i+1)].push(re, misses); + } + else { + tmp[blk_index] = re->tag_ptr; + blk_index++; + delete re; + repl_pool.sample(i); + } + } + } + if (blk_index >= n) + return tmp; + /* search the fresh pool */ + + fatal("No N replacements found"); + return NULL; +} + +void +GenRepl::doAdvance(std::list<unsigned long> &demoted) +{ + int i; + int num_seen = 0; + GenReplEntry *re; + misses++; + for (i=0; i<num_pools; i++) { + while (misses-pools[i].oldest > pool_res && (re = pools[i].pop())!=NULL) { + if (iic->clearRef(re->tag_ptr)) { + pools[(((i+1)== num_pools)? i :i+1)].push(re, misses); + /** @todo Not really demoted, but use it for now. */ + demoted.push_back(re->tag_ptr); + advance_pool.sample(i); + } + else { + pools[(((i-1)<0)?i:i-1)].push(re, misses); + demoted.push_back(re->tag_ptr); + demote_pool.sample(i); + } + } + num_seen += pools[i].size; + } + while (misses-pools[num_pools].oldest > fresh_res + && (re = pools[num_pools].pop())!=NULL) { + num_pool_entries++; + if (iic->clearRef(re->tag_ptr)) { + pools[num_pools/2].push(re, misses); + /** @todo Not really demoted, but use it for now. */ + demoted.push_back(re->tag_ptr); + advance_pool.sample(num_pools); + } + else { + pools[num_pools/2-1].push(re, misses); + demoted.push_back(re->tag_ptr); + demote_pool.sample(num_pools); + } + } +} + +void* +GenRepl::add(unsigned long tag_index) +{ + GenReplEntry *re = new GenReplEntry; + re->tag_ptr = tag_index; + re->valid = true; + pools[num_pools].push(re, misses); + num_entries++; + return (void*)re; +} + +void +GenRepl::regStats(const string name) +{ + using namespace Stats; + + /** GEN statistics */ + repl_pool + .init(0, 16, 1) + .name(name + ".repl_pool_dist") + .desc("Dist. of Repl. across pools") + .flags(pdf) + ; + + advance_pool + .init(0, 16, 1) + .name(name + ".advance_pool_dist") + .desc("Dist. of Repl. across pools") + .flags(pdf) + ; + + demote_pool + .init(0, 16, 1) + .name(name + ".demote_pool_dist") + .desc("Dist. of Repl. across pools") + .flags(pdf) + ; +} + +int +GenRepl::fixTag(void* _re, unsigned long old_index, unsigned long new_index) +{ + GenReplEntry *re = (GenReplEntry*)_re; + assert(re->valid); + if (re->tag_ptr == old_index) { + re->tag_ptr = new_index; + return 1; + } + fatal("Repl entry: tag ptrs do not match"); + return 0; +} + +bool +GenRepl::findTagPtr(unsigned long index) +{ + for (int i = 0; i < num_pools + 1; ++i) { + list<GenReplEntry*>::const_iterator iter = pools[i].entries.begin(); + list<GenReplEntry*>::const_iterator end = pools[i].entries.end(); + for (; iter != end; ++iter) { + if ((*iter)->valid && (*iter)->tag_ptr == index) { + return true; + } + } + } + return false; +} + +GenRepl * +GenReplParams::create() +{ + return new GenRepl(this); +} |