gem5/src/mem/cache/tags/lfu.cc
Sanchayan Maity 6f9826e621 mem: cache: tags: Implement LFU Cache replacement policy
Implement Least Frequently Used Cache replacement policy.
2017-03-23 17:21:09 +05:30

81 lines
1.6 KiB
C++

/*
* Authors: Sanchayan Maity
*/
/**
* @file
* Definitions of a LFU tag store.
*/
#include "mem/cache/tags/lfu.hh"
#include "debug/CacheRepl.hh"
#include "mem/cache/base.hh"
LFU::LFU(const Params *p) : BaseSetAssoc(p)
{
}
CacheBlk*
LFU::accessBlock(Addr addr, bool is_secure, Cycles &lat, int master_id)
{
CacheBlk *blk = BaseSetAssoc::accessBlock(addr,
is_secure, lat, master_id);
return blk;
}
CacheBlk*
LFU::findVictim(Addr addr)
{
int set = extractSet(addr);
int minimum;
BlkType *blk = nullptr;
for (int i = 0; i < allocAssoc; ++i) {
BlkType *b = sets[set].blks[i];
if (i == 0) {
minimum = b->refCount;
blk = b;
}
else if (b->refCount < minimum) {
minimum = b->refCount;
blk = b;
}
}
assert(!blk || blk->way < allocAssoc);
if (blk && blk->isValid()) {
DPRINTF(CacheRepl,
"set %x: selecting blk %x for replacement\n",
set, regenerateBlkAddr(blk->tag, set));
}
return blk;
}
void
LFU::insertBlock(PacketPtr pkt, BlkType *blk)
{
BaseSetAssoc::insertBlock(pkt, blk);
int set = extractSet(pkt->getAddr());
sets[set].moveToHead(blk);
}
void
LFU::invalidate(CacheBlk *blk)
{
BaseSetAssoc::invalidate(blk);
int set = blk->set;
sets[set].moveToTail(blk);
}
LFU*
LFUParams::create()
{
return new LFU(this);
}