derek/gem5
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

mem-cache: Remove IP dependency from TaggedEntry

Browse Source 
We don't store a pointer to the indexing policy anymore.
Instead, we register a tag extractor callback when we
construct the TaggedEntry

Change-Id: I79dbc1bc5c5ce90d350e83451f513c05da9f0d61
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
This commit is contained in:
Giacomo Travaglini
2024-08-20 10:31:20 +01:00
parent b6d34db216
commit c52f77a1d7
21 changed files with 126 additions and 98 deletions
Download Patch File Download Diff File Expand all files Collapse all files

3
src/mem/cache/base.cc vendored
View File

@@ -125,7 +125,8 @@ BaseCache::BaseCache(const BaseCacheParams &p, unsigned blk_size)
// forward snoops is overridden in init() once we can query
// whether the connected requestor is actually snooping or not
tempBlock = new TempCacheBlk(blkSize, tags->params().indexing_policy);
tempBlock = new TempCacheBlk(blkSize,
genTagExtractor(tags->params().indexing_policy));
tags->tagsInit();
if (prefetcher)

7
src/mem/cache/cache_blk.hh vendored
View File

@@ -153,7 +153,7 @@ class CacheBlk : public TaggedEntry
std::list<Lock> lockList;
public:
CacheBlk() : TaggedEntry(nullptr)
CacheBlk() : TaggedEntry()
{
invalidate();
}
@@ -526,11 +526,10 @@ class TempCacheBlk final : public CacheBlk
* Creates a temporary cache block, with its own storage.
* @param size The size (in bytes) of this cache block.
*/
TempCacheBlk(unsigned size, TaggedIndexingPolicy *ip) : CacheBlk()
TempCacheBlk(unsigned size, TagExtractor ext) : CacheBlk()
{
data = new uint8_t[size];
setIndexingPolicy(ip);
registerTagExtractor(ext);
}
TempCacheBlk(const TempCacheBlk&) = delete;
using CacheBlk::operator=;

2
src/mem/cache/prefetch/access_map_pattern_matching.cc vendored
View File

@@ -56,7 +56,7 @@ AccessMapPatternMatching::AccessMapPatternMatching(
p.access_map_table_replacement_policy,
p.access_map_table_indexing_policy,
AccessMapEntry(hotZoneSize / blkSize,
p.access_map_table_indexing_policy)),
genTagExtractor(p.access_map_table_indexing_policy))),
numGoodPrefetches(0), numTotalPrefetches(0), numRawCacheMisses(0),
numRawCacheHits(0), degree(startDegree), usefulDegree(startDegree),
epochEvent([this]{ processEpochEvent(); }, name())

5
src/mem/cache/prefetch/access_map_pattern_matching.hh vendored
View File

@@ -95,9 +95,10 @@ class AccessMapPatternMatching : public ClockedObject
/** vector containing the state of the cachelines in this zone */
std::vector<AccessMapState> states;
AccessMapEntry(size_t num_entries, TaggedIndexingPolicy *ip)
: TaggedEntry(ip), states(num_entries, AM_INIT)
AccessMapEntry(size_t num_entries, TagExtractor ext)
: TaggedEntry(), states(num_entries, AM_INIT)
{
registerTagExtractor(ext);
}
void

4
src/mem/cache/prefetch/indirect_memory.cc vendored
View File

@@ -49,12 +49,12 @@ IndirectMemory::IndirectMemory(const IndirectMemoryPrefetcherParams &p)
p.pt_table_replacement_policy,
p.pt_table_indexing_policy,
PrefetchTableEntry(p.num_indirect_counter_bits,
p.pt_table_indexing_policy)),
genTagExtractor(p.pt_table_indexing_policy))),
ipd((name() + ".IPD").c_str(), p.ipd_table_entries, p.ipd_table_assoc,
p.ipd_table_replacement_policy,
p.ipd_table_indexing_policy,
IndirectPatternDetectorEntry(p.addr_array_len, shiftValues.size(),
p.ipd_table_indexing_policy)),
genTagExtractor(p.ipd_table_indexing_policy))),
ipdEntryTrackingMisses(nullptr), byteOrder(p.sys->getGuestByteOrder())
{
}

14
src/mem/cache/prefetch/indirect_memory.hh vendored
View File

@@ -99,13 +99,14 @@ class IndirectMemory : public Queued
*/
bool increasedIndirectCounter;
PrefetchTableEntry(unsigned indirect_counter_bits,
TaggedIndexingPolicy *ip)
: TaggedEntry(ip), address(0), secure(false), streamCounter(0),
PrefetchTableEntry(unsigned indirect_counter_bits, TagExtractor ext)
: TaggedEntry(), address(0), secure(false), streamCounter(0),
enabled(false), index(0), baseAddr(0), shift(0),
indirectCounter(indirect_counter_bits),
increasedIndirectCounter(false)
{}
{
registerTagExtractor(ext);
}
void
invalidate() override
@@ -145,11 +146,12 @@ class IndirectMemory : public Queued
IndirectPatternDetectorEntry(unsigned int num_addresses,
unsigned int num_shifts,
TaggedIndexingPolicy *ip)
: TaggedEntry(ip), idx1(0), idx2(0), secondIndexSet(false),
TagExtractor ext)
: TaggedEntry(), idx1(0), idx2(0), secondIndexSet(false),
numMisses(0),
baseAddr(num_addresses, std::vector<Addr>(num_shifts))
{
registerTagExtractor(ext);
}
void

16
src/mem/cache/prefetch/irregular_stream_buffer.cc vendored
View File

@@ -44,25 +44,27 @@ IrregularStreamBuffer::IrregularStreamBuffer(
prefetchCandidatesPerEntry(p.prefetch_candidates_per_entry),
degree(p.degree),
trainingUnit((name() + ".TrainingUnit").c_str(),
p.training_unit_entries,
p.training_unit_assoc,
p.training_unit_replacement_policy,
p.training_unit_indexing_policy,
TrainingUnitEntry(p.training_unit_indexing_policy)),
p.training_unit_entries,
p.training_unit_assoc,
p.training_unit_replacement_policy,
p.training_unit_indexing_policy,
TrainingUnitEntry(genTagExtractor(p.training_unit_indexing_policy))),
psAddressMappingCache((name() + ".PSAddressMappingCache").c_str(),
p.address_map_cache_entries,
p.address_map_cache_assoc,
p.ps_address_map_cache_replacement_policy,
p.ps_address_map_cache_indexing_policy,
AddressMappingEntry(prefetchCandidatesPerEntry,
p.num_counter_bits, p.ps_address_map_cache_indexing_policy)),
p.num_counter_bits,
genTagExtractor(p.ps_address_map_cache_indexing_policy))),
spAddressMappingCache((name() + ".SPAddressMappingCache").c_str(),
p.address_map_cache_entries,
p.address_map_cache_assoc,
p.sp_address_map_cache_replacement_policy,
p.sp_address_map_cache_indexing_policy,
AddressMappingEntry(prefetchCandidatesPerEntry,
p.num_counter_bits, p.sp_address_map_cache_indexing_policy)),
p.num_counter_bits,
genTagExtractor(p.sp_address_map_cache_indexing_policy))),
structuralAddressCounter(0)
{
assert(isPowerOf2(prefetchCandidatesPerEntry));

13
src/mem/cache/prefetch/irregular_stream_buffer.hh vendored
View File

@@ -67,9 +67,11 @@ class IrregularStreamBuffer : public Queued
*/
struct TrainingUnitEntry : public TaggedEntry
{
TrainingUnitEntry(TaggedIndexingPolicy *ip)
: TaggedEntry(ip), lastAddress(0), lastAddressSecure(false)
{}
TrainingUnitEntry(TagExtractor ext)
: TaggedEntry(), lastAddress(0), lastAddressSecure(false)
{
registerTagExtractor(ext);
}
Addr lastAddress;
bool lastAddressSecure;
};
@@ -93,9 +95,10 @@ class IrregularStreamBuffer : public Queued
{
std::vector<AddressMapping> mappings;
AddressMappingEntry(size_t num_mappings, unsigned counter_bits,
TaggedIndexingPolicy *ip)
: TaggedEntry(ip), mappings(num_mappings, counter_bits)
TagExtractor ext)
: TaggedEntry(), mappings(num_mappings, counter_bits)
{
registerTagExtractor(ext);
}
void

2
src/mem/cache/prefetch/pif.cc vendored
View File

@@ -48,7 +48,7 @@ PIF::PIF(const PIFPrefetcherParams &p)
index((name() + ".PIFIndex").c_str(), p.index_entries, p.index_assoc,
p.index_replacement_policy,
p.index_indexing_policy,
IndexEntry(p.index_indexing_policy)),
IndexEntry(genTagExtractor(p.index_indexing_policy))),
streamAddressBuffer(p.stream_address_buffer_entries),
listenersPC()
{

7
src/mem/cache/prefetch/pif.hh vendored
View File

@@ -137,7 +137,12 @@ class PIF : public Queued
struct IndexEntry : public TaggedEntry
{
using TaggedEntry::TaggedEntry;
IndexEntry(TagExtractor ext)
: TaggedEntry()
{
registerTagExtractor(ext);
}
HistoryBuffer::iterator historyIt;
};

22
src/mem/cache/prefetch/signature_path.cc vendored
View File

@@ -48,18 +48,18 @@ SignaturePath::SignaturePath(const SignaturePathPrefetcherParams &p)
prefetchConfidenceThreshold(p.prefetch_confidence_threshold),
lookaheadConfidenceThreshold(p.lookahead_confidence_threshold),
signatureTable((name() + ".SignatureTable").c_str(),
p.signature_table_entries,
p.signature_table_assoc,
p.signature_table_replacement_policy,
p.signature_table_indexing_policy,
SignatureEntry(p.signature_table_indexing_policy)),
p.signature_table_entries,
p.signature_table_assoc,
p.signature_table_replacement_policy,
p.signature_table_indexing_policy,
SignatureEntry(genTagExtractor(p.signature_table_indexing_policy))),
patternTable((name() + ".PatternTable").c_str(),
p.pattern_table_entries,
p.pattern_table_assoc,
p.pattern_table_replacement_policy,
p.pattern_table_indexing_policy,
PatternEntry(stridesPerPatternEntry, p.num_counter_bits,
p.pattern_table_indexing_policy))
p.pattern_table_entries,
p.pattern_table_assoc,
p.pattern_table_replacement_policy,
p.pattern_table_indexing_policy,
PatternEntry(stridesPerPatternEntry, p.num_counter_bits,
genTagExtractor(p.pattern_table_indexing_policy)))
{
fatal_if(prefetchConfidenceThreshold < 0,
"The prefetch confidence threshold must be greater than 0\n");

13
src/mem/cache/prefetch/signature_path.hh vendored
View File

@@ -80,9 +80,11 @@ class SignaturePath : public Queued
signature_t signature;
/** Last accessed block within a page */
stride_t lastBlock;
SignatureEntry(TaggedIndexingPolicy *ip)
: TaggedEntry(ip), signature(0), lastBlock(0)
{}
SignatureEntry(TagExtractor ext)
: TaggedEntry(), signature(0), lastBlock(0)
{
registerTagExtractor(ext);
}
};
/** Signature table */
AssociativeCache<SignatureEntry> signatureTable;
@@ -105,10 +107,11 @@ class SignaturePath : public Queued
/** use counter, used by SPPv2 */
SatCounter8 counter;
PatternEntry(size_t num_strides, unsigned counter_bits,
TaggedIndexingPolicy *ip)
: TaggedEntry(ip), strideEntries(num_strides, counter_bits),
TagExtractor ext)
: TaggedEntry(), strideEntries(num_strides, counter_bits),
counter(counter_bits)
{
registerTagExtractor(ext);
}
/** Reset the entries to their initial values */

12
src/mem/cache/prefetch/signature_path_v2.cc vendored
View File

@@ -54,12 +54,12 @@ namespace prefetch
SignaturePathV2::SignaturePathV2(const SignaturePathPrefetcherV2Params &p)
: SignaturePath(p),
globalHistoryRegister((name() + ".GlobalHistoryRegister").c_str(),
p.global_history_register_entries,
p.global_history_register_entries,
p.global_history_register_replacement_policy,
p.global_history_register_indexing_policy,
GlobalHistoryEntry(
p.global_history_register_indexing_policy))
p.global_history_register_entries,
p.global_history_register_entries,
p.global_history_register_replacement_policy,
p.global_history_register_indexing_policy,
GlobalHistoryEntry(
genTagExtractor(p.global_history_register_indexing_policy)))
{
}

8
src/mem/cache/prefetch/signature_path_v2.hh vendored
View File

@@ -62,10 +62,12 @@ class SignaturePathV2 : public SignaturePath
double confidence;
stride_t lastBlock;
stride_t delta;
GlobalHistoryEntry(TaggedIndexingPolicy *ip)
: TaggedEntry(ip), signature(0), confidence(0.0), lastBlock(0),
GlobalHistoryEntry(TagExtractor ext)
: TaggedEntry(), signature(0), confidence(0.0), lastBlock(0),
delta(0)
{}
{
registerTagExtractor(ext);
}
};
/** Global History Register */
AssociativeCache<GlobalHistoryEntry> globalHistoryRegister;

28
src/mem/cache/prefetch/spatio_temporal_memory_streaming.cc vendored
View File

@@ -42,21 +42,21 @@ STeMS::STeMS(const STeMSPrefetcherParams &p)
spatialRegionSizeBits(floorLog2(p.spatial_region_size)),
reconstructionEntries(p.reconstruction_entries),
activeGenerationTable((name() + ".ActiveGenerationTable").c_str(),
p.active_generation_table_entries,
p.active_generation_table_assoc,
p.active_generation_table_replacement_policy,
p.active_generation_table_indexing_policy,
ActiveGenerationTableEntry(
spatialRegionSize / blkSize,
p.active_generation_table_indexing_policy)),
p.active_generation_table_entries,
p.active_generation_table_assoc,
p.active_generation_table_replacement_policy,
p.active_generation_table_indexing_policy,
ActiveGenerationTableEntry(
spatialRegionSize / blkSize,
genTagExtractor(p.active_generation_table_indexing_policy))),
patternSequenceTable((name() + ".PatternSequenceTable").c_str(),
p.pattern_sequence_table_entries,
p.pattern_sequence_table_assoc,
p.pattern_sequence_table_replacement_policy,
p.pattern_sequence_table_indexing_policy,
ActiveGenerationTableEntry(
spatialRegionSize / blkSize,
p.pattern_sequence_table_indexing_policy)),
p.pattern_sequence_table_entries,
p.pattern_sequence_table_assoc,
p.pattern_sequence_table_replacement_policy,
p.pattern_sequence_table_indexing_policy,
ActiveGenerationTableEntry(
spatialRegionSize / blkSize,
genTagExtractor(p.pattern_sequence_table_indexing_policy))),
rmob(p.region_miss_order_buffer_entries),
addDuplicateEntriesToRMOB(p.add_duplicate_entries_to_rmob),
lastTriggerCounter(0)

6
src/mem/cache/prefetch/spatio_temporal_memory_streaming.hh vendored
View File

@@ -94,11 +94,11 @@ class STeMS : public Queued
/** Sequence of accesses */
std::vector<SequenceEntry> sequence;
ActiveGenerationTableEntry(int num_positions,
TaggedIndexingPolicy *ip)
: TaggedEntry(ip), paddress(0), pc(0),
ActiveGenerationTableEntry(int num_positions, TagExtractor ext)
: TaggedEntry(), paddress(0), pc(0),
seqCounter(0), sequence(num_positions)
{
registerTagExtractor(ext);
}
void

8
src/mem/cache/prefetch/stride.cc vendored
View File

@@ -63,9 +63,10 @@ namespace prefetch
{
Stride::StrideEntry::StrideEntry(const SatCounter8& init_confidence,
TaggedIndexingPolicy *ip)
: TaggedEntry(ip), confidence(init_confidence)
TagExtractor ext)
: TaggedEntry(), confidence(init_confidence)
{
registerTagExtractor(ext);
invalidate();
}
@@ -114,7 +115,8 @@ Stride::allocateNewContext(int context)
pcTableInfo.assoc,
pcTableInfo.replacementPolicy,
pcTableInfo.indexingPolicy,
StrideEntry(initConfidence, pcTableInfo.indexingPolicy)));
StrideEntry(initConfidence,
genTagExtractor(pcTableInfo.indexingPolicy))));
DPRINTF(HWPrefetch, "Adding context %i with stride entries\n", context);

3
src/mem/cache/prefetch/stride.hh vendored
View File

@@ -136,8 +136,7 @@ class Stride : public Queued
/** Tagged by hashed PCs. */
struct StrideEntry : public TaggedEntry
{
StrideEntry(const SatCounter8& init_confidence,
TaggedIndexingPolicy *ip);
StrideEntry(const SatCounter8& init_confidence, TagExtractor ext);
void invalidate() override;

2
src/mem/cache/tags/base_set_assoc.cc vendored
View File

@@ -84,7 +84,7 @@ BaseSetAssoc::tagsInit()
blk->replacementData = replacementPolicy->instantiateEntry();
// This is not used as of now but we set it for security
blk->setIndexingPolicy(indexingPolicy);
blk->registerTagExtractor(genTagExtractor(indexingPolicy));
}
}

2
src/mem/cache/tags/sector_blk.cc vendored
View File

@@ -112,7 +112,7 @@ SectorSubBlk::print() const
}
SectorBlk::SectorBlk()
: TaggedEntry(nullptr), _validCounter(0)
: TaggedEntry(), _validCounter(0)
{
}

47
src/mem/cache/tags/tagged_entry.hh vendored
View File

@@ -112,12 +112,19 @@ class TaggedEntry : public ReplaceableEntry
public:
using KeyType = TaggedTypes::KeyType;
using IndexingPolicy = TaggedIndexingPolicy;
using TagExtractor = std::function<Addr(Addr)>;
TaggedEntry(IndexingPolicy *ip)
: _valid(false), _secure(false), _tag(MaxAddr), indexingPolicy(ip)
TaggedEntry()
: _valid(false), _secure(false), _tag(MaxAddr)
{}
~TaggedEntry() = default;
void
registerTagExtractor(TagExtractor ext)
{
extractTag = ext;
}
/**
* Checks if the entry is valid.
*
@@ -177,12 +184,6 @@ class TaggedEntry : public ReplaceableEntry
clearSecure();
}
void
setIndexingPolicy(IndexingPolicy *ip)
{
indexingPolicy = ip;
}
std::string
print() const override
{
@@ -201,11 +202,8 @@ class TaggedEntry : public ReplaceableEntry
/** Set secure bit. */
virtual void setSecure() { _secure = true; }
Addr
extractTag(Addr addr) const
{
return indexingPolicy->extractTag(addr);
}
/** Clear secure bit. Should be only used by the invalidation function. */
void clearSecure() { _secure = false; }
/** Set valid bit. The block must be invalid beforehand. */
virtual void
@@ -215,6 +213,9 @@ class TaggedEntry : public ReplaceableEntry
_valid = true;
}
/** Callback used to extract the tag from the entry */
TagExtractor extractTag;
private:
/**
* Valid bit. The contents of this entry are only valid if this bit is set.
@@ -231,14 +232,22 @@ class TaggedEntry : public ReplaceableEntry
/** The entry's tag. */
Addr _tag;
/** Reference to the indexing policy */
IndexingPolicy *indexingPolicy;
/** Clear secure bit. Should be only used by the invalidation function. */
void clearSecure() { _secure = false; }
};
/**
* This helper generates an a tag extractor function object
* which will be typically used by Replaceable entries indexed
* with the TaggedIndexingPolicy.
* It allows to "decouple" indexing from tagging. Those entries
* would call the functor without directly holding a pointer
* to the indexing policy which should reside in the cache.
*/
static constexpr auto
genTagExtractor(TaggedIndexingPolicy *ip)
{
return [ip] (Addr addr) { return ip->extractTag(addr); };
}
} // namespace gem5
#endif//__CACHE_TAGGED_ENTRY_HH__