diff options
author | Daniel R. Carvalho <odanrc@yahoo.com.br> | 2018-02-19 15:13:11 +0100 |
---|---|---|
committer | Daniel Carvalho <odanrc@yahoo.com.br> | 2018-03-22 14:50:23 +0000 |
commit | d207e9ccee411877fdeac80bb68a27900560f50f (patch) | |
tree | 120810cf72c52ed5df29436552e06f1fb11aa5ce /src/mem/cache/tags/fa_lru.hh | |
parent | 0473286ab1e9992a906eff380000bf90c82eeccb (diff) | |
download | gem5-d207e9ccee411877fdeac80bb68a27900560f50f.tar.xz |
mem-cache: Split array indexing and replacement policies.
Replacement policies (LRU, Random) are currently considered as array
indexing methods, but have completely different functionalities:
- Array indexers determine the possible locations for block allocation.
This information is used to generate replacement candidates when
conflicts happen.
- Replacement policies determine which of the replacement candidates
should be evicted to make room for new allocations.
For this reason, they were split into different classes. Advantages:
- Easier and more straightforward to implement other replacement
policies (RRIP, LFU, ARC, ...)
- Allow easier future implementation of cache organization schemes
As now we can't assure the use of sets, the previous way to create a
true LRU is not viable. Now a timestamp_bits parameter controls how
many bits are dedicated for the timestamp, and a true LRU can be
achieved through an infinite number of bits (although a few bits suffice
in practice).
Change-Id: I23750db121f1474d17831137e6ff618beb2b3eda
Reviewed-on: https://gem5-review.googlesource.com/8501
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Diffstat (limited to 'src/mem/cache/tags/fa_lru.hh')
-rw-r--r-- | src/mem/cache/tags/fa_lru.hh | 9 |
1 files changed, 4 insertions, 5 deletions
diff --git a/src/mem/cache/tags/fa_lru.hh b/src/mem/cache/tags/fa_lru.hh index 559f56e28..7f3f99ae0 100644 --- a/src/mem/cache/tags/fa_lru.hh +++ b/src/mem/cache/tags/fa_lru.hh @@ -67,8 +67,6 @@ public: FALRUBlk *prev; /** The next block in LRU order. */ FALRUBlk *next; - /** Has this block been touched? */ - bool isTouched; /** * A bit mask of the sizes of cache that this block is resident in. @@ -204,9 +202,10 @@ public: CacheBlk* findBlock(Addr addr, bool is_secure) const override; /** - * Find a replacement block for the address provided. - * @param pkt The request to a find a replacement candidate for. - * @return The block to place the replacement in. + * Find replacement victim based on address. + * + * @param addr Address to find a victim for. + * @return Cache block to be replaced. */ CacheBlk* findVictim(Addr addr) override; |