From c68032ddcbf0aad10123710e7c7c932bf52061a0 Mon Sep 17 00:00:00 2001 From: Lisa Hsu Date: Tue, 4 Nov 2008 11:35:58 -0500 Subject: decouple eviction from insertion in the cache. --- src/mem/cache/cache_impl.hh | 8 +++++--- src/mem/cache/tags/fa_lru.cc | 7 ++++++- src/mem/cache/tags/fa_lru.hh | 4 +++- src/mem/cache/tags/iic.cc | 7 ++++++- src/mem/cache/tags/iic.hh | 4 +++- src/mem/cache/tags/lru.cc | 18 ++++++++++++++---- src/mem/cache/tags/lru.hh | 16 ++++++++++++---- 7 files changed, 49 insertions(+), 15 deletions(-) (limited to 'src/mem/cache') diff --git a/src/mem/cache/cache_impl.hh b/src/mem/cache/cache_impl.hh index af179ff91..40d1c9c2f 100644 --- a/src/mem/cache/cache_impl.hh +++ b/src/mem/cache/cache_impl.hh @@ -319,6 +319,7 @@ Cache::access(PacketPtr pkt, BlkType *&blk, incMissCount(pkt); return false; } + tags->insertBlock(pkt->getAddr(), blk); blk->status = BlkValid | BlkReadable; } std::memcpy(blk->data, pkt->getPtr(), blkSize); @@ -879,7 +880,7 @@ template typename Cache::BlkType* Cache::allocateBlock(Addr addr, PacketList &writebacks) { - BlkType *blk = tags->findReplacement(addr, writebacks); + BlkType *blk = tags->findVictim(addr, writebacks); if (blk->isValid()) { Addr repl_addr = tags->regenerateBlkAddr(blk->tag, blk->set); @@ -890,6 +891,7 @@ Cache::allocateBlock(Addr addr, PacketList &writebacks) assert(!blk->isWritable()); assert(repl_mshr->needsExclusive()); // too hard to replace block with transient state + // allocation failed, block not inserted return NULL; } else { DPRINTF(Cache, "replacement: replacing %x with %x: %s\n", @@ -903,8 +905,6 @@ Cache::allocateBlock(Addr addr, PacketList &writebacks) } } - // Set tag for new block. Caller is responsible for setting status. - blk->tag = tags->extractTag(addr); return blk; } @@ -937,6 +937,8 @@ Cache::handleFill(PacketPtr pkt, BlkType *blk, tempBlock->set = tags->extractSet(addr); tempBlock->tag = tags->extractTag(addr); DPRINTF(Cache, "using temp block for %x\n", addr); + } else { + tags->insertBlock(addr, blk); } } else { // existing block... probably an upgrade diff --git a/src/mem/cache/tags/fa_lru.cc b/src/mem/cache/tags/fa_lru.cc index aeb20aa4d..f92d4cb37 100644 --- a/src/mem/cache/tags/fa_lru.cc +++ b/src/mem/cache/tags/fa_lru.cc @@ -207,7 +207,7 @@ FALRU::findBlock(Addr addr) const } FALRUBlk* -FALRU::findReplacement(Addr addr, PacketList &writebacks) +FALRU::findVictim(Addr addr, PacketList &writebacks) { FALRUBlk * blk = tail; assert(blk->inCache == 0); @@ -228,6 +228,11 @@ FALRU::findReplacement(Addr addr, PacketList &writebacks) return blk; } +void +FALRU::insertBlock(Addr addr, FALRU::BlkType *blk) +{ +} + void FALRU::moveToHead(FALRUBlk *blk) { diff --git a/src/mem/cache/tags/fa_lru.hh b/src/mem/cache/tags/fa_lru.hh index dfb21c08f..a740d962f 100644 --- a/src/mem/cache/tags/fa_lru.hh +++ b/src/mem/cache/tags/fa_lru.hh @@ -197,7 +197,9 @@ public: * @param writebacks List for any writebacks to be performed. * @return The block to place the replacement in. */ - FALRUBlk* findReplacement(Addr addr, PacketList & writebacks); + FALRUBlk* findVictim(Addr addr, PacketList & writebacks); + + void insertBlock(Addr addr, BlkType *blk); /** * Return the hit latency of this cache. diff --git a/src/mem/cache/tags/iic.cc b/src/mem/cache/tags/iic.cc index 6abc0facf..2b34634ab 100644 --- a/src/mem/cache/tags/iic.cc +++ b/src/mem/cache/tags/iic.cc @@ -297,7 +297,7 @@ IIC::findBlock(Addr addr) const IICTag* -IIC::findReplacement(Addr addr, PacketList &writebacks) +IIC::findVictim(Addr addr, PacketList &writebacks) { DPRINTF(IIC, "Finding Replacement for %x\n", addr); unsigned set = hash(addr); @@ -339,6 +339,11 @@ IIC::findReplacement(Addr addr, PacketList &writebacks) return tag_ptr; } +void +IIC::insertBlock(Addr addr, BlkType* blk) +{ +} + void IIC::freeReplacementBlock(PacketList & writebacks) { diff --git a/src/mem/cache/tags/iic.hh b/src/mem/cache/tags/iic.hh index 26f9858c4..984506a93 100644 --- a/src/mem/cache/tags/iic.hh +++ b/src/mem/cache/tags/iic.hh @@ -435,7 +435,9 @@ class IIC : public BaseTags * @param writebacks List for any writebacks to be performed. * @return The block to place the replacement in. */ - IICTag* findReplacement(Addr addr, PacketList &writebacks); + IICTag* findVictim(Addr addr, PacketList &writebacks); + + void insertBlock(Addr addr, BlkType *blk); /** * Read the data from the internal storage of the given cache block. diff --git a/src/mem/cache/tags/lru.cc b/src/mem/cache/tags/lru.cc index f5cf33696..ff353ff6a 100644 --- a/src/mem/cache/tags/lru.cc +++ b/src/mem/cache/tags/lru.cc @@ -183,12 +183,11 @@ LRU::findBlock(Addr addr) const } LRUBlk* -LRU::findReplacement(Addr addr, PacketList &writebacks) +LRU::findVictim(Addr addr, PacketList &writebacks) { unsigned set = extractSet(addr); // grab a replacement candidate LRUBlk *blk = sets[set].blks[assoc-1]; - sets[set].moveToHead(blk); if (blk->isValid()) { replacements[0]++; totalRefs += blk->refCount; @@ -197,7 +196,14 @@ LRU::findReplacement(Addr addr, PacketList &writebacks) DPRINTF(CacheRepl, "set %x: selecting blk %x for replacement\n", set, regenerateBlkAddr(blk->tag, set)); - } else if (!blk->isTouched) { + } + return blk; +} + +void +LRU::insertBlock(Addr addr, LRU::BlkType *blk) +{ + if (!blk->isTouched) { tagsInUse++; blk->isTouched = true; if (!warmedUp && tagsInUse.value() >= warmupBound) { @@ -206,7 +212,11 @@ LRU::findReplacement(Addr addr, PacketList &writebacks) } } - return blk; + // Set tag for new block. Caller is responsible for setting status. + blk->tag = extractTag(addr); + + unsigned set = extractSet(addr); + sets[set].moveToHead(blk); } void diff --git a/src/mem/cache/tags/lru.hh b/src/mem/cache/tags/lru.hh index 4f4c495f3..79af973a0 100644 --- a/src/mem/cache/tags/lru.hh +++ b/src/mem/cache/tags/lru.hh @@ -180,12 +180,20 @@ public: LRUBlk* findBlock(Addr addr) const; /** - * Find a replacement block for the address provided. - * @param pkt The request to a find a replacement candidate for. + * Find a block to evict for the address provided. + * @param addr The addr to a find a replacement candidate for. * @param writebacks List for any writebacks to be performed. - * @return The block to place the replacement in. + * @return The candidate block. */ - LRUBlk* findReplacement(Addr addr, PacketList &writebacks); + LRUBlk* findVictim(Addr addr, PacketList &writebacks); + + /** + * Insert the new block into the cache. For LRU this means inserting into + * the MRU position of the set. + * @param addr The address to update. + * @param blk The block to update. + */ + void insertBlock(Addr addr, BlkType *blk); /** * Generate the tag from the given address. -- cgit v1.2.3