mem-cache: Make compression size threshold a percentage
By changing the parameter into a percentage, changing the block
size will automatically reconfigure the size threshold. Also,
change the default percentage to 50% to avoid storing blocks
unlikely to co-allocate in compressed format.
Change-Id: I1458f19db39becc2d40c00269132fea01770016f
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/33385
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
diff --git a/src/mem/cache/compressors/Compressors.py b/src/mem/cache/compressors/Compressors.py
index 01cb619..9fa06f2 100644
--- a/src/mem/cache/compressors/Compressors.py
+++ b/src/mem/cache/compressors/Compressors.py
@@ -37,9 +37,9 @@
block_size = Param.Int(Parent.cache_line_size, "Block size in bytes")
chunk_size_bits = Param.Unsigned(32,
"Size of a parsing data chunk (in bits)")
- size_threshold = Param.Unsigned(Parent.cache_line_size, "Minimum size, "
- "in bytes, in which a block must be compressed to. Otherwise it is "
- "stored in its uncompressed state")
+ size_threshold_percentage = Param.Percent(50,
+ "Minimum percentage of the block size, a compressed block must "
+ "achieve to be stored in compressed format")
class BaseDictionaryCompressor(BaseCacheCompressor):
type = 'BaseDictionaryCompressor'
diff --git a/src/mem/cache/compressors/base.cc b/src/mem/cache/compressors/base.cc
index 5b96e97..e12e36e 100644
--- a/src/mem/cache/compressors/base.cc
+++ b/src/mem/cache/compressors/base.cc
@@ -77,7 +77,7 @@
Base::Base(const Params *p)
: SimObject(p), blkSize(p->block_size), chunkSizeBits(p->chunk_size_bits),
- sizeThreshold(p->size_threshold),
+ sizeThreshold((blkSize * p->size_threshold_percentage) / 100),
stats(*this)
{
fatal_if(64 % chunkSizeBits,
