mem-cache: Fix invalidation of prefetchers
Add an invalidation function to the AssociativeSet, so that entries
can be properly invalidated by also invalidating their replacement
data.
Both setInvalid and reset have been merged into invalidate to
indicate users that they are using an incorrect approach by
generating compilation errors, and to match CacheBlk's naming
convention.
Change-Id: I568076a3b5adda8b1311d9498b086c0dab457a14
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/24529
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/prefetch/access_map_pattern_matching.hh b/src/mem/cache/prefetch/access_map_pattern_matching.hh
index 397bc78..6e2e194 100644
--- a/src/mem/cache/prefetch/access_map_pattern_matching.hh
+++ b/src/mem/cache/prefetch/access_map_pattern_matching.hh
@@ -89,12 +89,15 @@
/** vector containing the state of the cachelines in this zone */
std::vector<AccessMapState> states;
- AccessMapEntry(size_t num_entries) : states(num_entries, AM_INIT)
- {}
-
- /** Reset the entries to their initial values */
- void reset() override
+ AccessMapEntry(size_t num_entries)
+ : TaggedEntry(), states(num_entries, AM_INIT)
{
+ }
+
+ void
+ invalidate() override
+ {
+ TaggedEntry::invalidate();
for (auto &entry : states) {
entry = AM_INIT;
}
diff --git a/src/mem/cache/prefetch/associative_set.hh b/src/mem/cache/prefetch/associative_set.hh
index e4e1b04..6228fe4 100644
--- a/src/mem/cache/prefetch/associative_set.hh
+++ b/src/mem/cache/prefetch/associative_set.hh
@@ -66,10 +66,10 @@
valid = true;
}
- /**
- * Sets the entry to invalid
- */
- void setInvalid() {
+ /** Invalidates the entry. */
+ virtual void
+ invalidate()
+ {
valid = false;
}
@@ -108,14 +108,6 @@
{
secure = s;
}
-
- /**
- * Resets the entry, this is called when an entry is evicted to allocate
- * a new one. Types inheriting this class should provide its own
- * implementation
- */
- virtual void reset () {
- }
};
/**
@@ -196,6 +188,13 @@
*/
void insertEntry(Addr addr, bool is_secure, Entry* entry);
+ /**
+ * Invalidate an entry and its respective replacement data.
+ *
+ * @param entry Entry to be invalidated.
+ */
+ void invalidate(Entry* entry);
+
/** Iterator types */
using const_iterator = typename std::vector<Entry>::const_iterator;
using iterator = typename std::vector<Entry>::iterator;
diff --git a/src/mem/cache/prefetch/associative_set_impl.hh b/src/mem/cache/prefetch/associative_set_impl.hh
index cc547e2..8acae62 100644
--- a/src/mem/cache/prefetch/associative_set_impl.hh
+++ b/src/mem/cache/prefetch/associative_set_impl.hh
@@ -87,7 +87,7 @@
Entry* victim = static_cast<Entry*>(replacementPolicy->getVictim(
selected_entries));
// There is only one eviction for this replacement
- victim->reset();
+ invalidate(victim);
return victim;
}
@@ -117,4 +117,12 @@
replacementPolicy->reset(entry->replacementData);
}
+template<class Entry>
+void
+AssociativeSet<Entry>::invalidate(Entry* entry)
+{
+ entry->invalidate();
+ replacementPolicy->invalidate(entry->replacementData);
+}
+
#endif//__CACHE_PREFETCH_ASSOCIATIVE_SET_IMPL_HH__
diff --git a/src/mem/cache/prefetch/delta_correlating_prediction_tables.cc b/src/mem/cache/prefetch/delta_correlating_prediction_tables.cc
index 4dbd596..8f7041f 100644
--- a/src/mem/cache/prefetch/delta_correlating_prediction_tables.cc
+++ b/src/mem/cache/prefetch/delta_correlating_prediction_tables.cc
@@ -44,8 +44,10 @@
}
void
-DeltaCorrelatingPredictionTables::DCPTEntry::reset()
+DeltaCorrelatingPredictionTables::DCPTEntry::invalidate()
{
+ TaggedEntry::invalidate();
+
for (auto &delta : deltas) {
delta = 0;
}
diff --git a/src/mem/cache/prefetch/delta_correlating_prediction_tables.hh b/src/mem/cache/prefetch/delta_correlating_prediction_tables.hh
index 86cf957..e4c466c 100644
--- a/src/mem/cache/prefetch/delta_correlating_prediction_tables.hh
+++ b/src/mem/cache/prefetch/delta_correlating_prediction_tables.hh
@@ -75,12 +75,12 @@
* Constructor
* @param num_deltas number of deltas stored in the entry
*/
- DCPTEntry(unsigned int num_deltas) : lastAddress(0), deltaPointer(0),
- deltas(num_deltas)
- {}
+ DCPTEntry(unsigned int num_deltas)
+ : TaggedEntry(), lastAddress(0), deltaPointer(0), deltas(num_deltas)
+ {
+ }
- /** Reset callback called when invalidating the entry */
- void reset() override;
+ void invalidate() override;
/**
* Adds an address to the entry, if the entry already existed, a delta
diff --git a/src/mem/cache/prefetch/indirect_memory.cc b/src/mem/cache/prefetch/indirect_memory.cc
index 7031051..0fd72cc 100644
--- a/src/mem/cache/prefetch/indirect_memory.cc
+++ b/src/mem/cache/prefetch/indirect_memory.cc
@@ -183,7 +183,7 @@
} else {
// Third access! no pattern has been found so far,
// release the IPD entry
- ipd_entry->reset();
+ ipd.invalidate(ipd_entry);
ipdEntryTrackingMisses = nullptr;
}
} else {
@@ -237,7 +237,7 @@
pt_entry->enabled = true;
pt_entry->indirectCounter.reset();
// Release the current IPD Entry
- entry->reset();
+ ipd.invalidate(entry);
// Do not track more misses
ipdEntryTrackingMisses = nullptr;
return;
diff --git a/src/mem/cache/prefetch/indirect_memory.hh b/src/mem/cache/prefetch/indirect_memory.hh
index f177c5c..07f3cb5 100644
--- a/src/mem/cache/prefetch/indirect_memory.hh
+++ b/src/mem/cache/prefetch/indirect_memory.hh
@@ -101,7 +101,10 @@
increasedIndirectCounter(false)
{}
- void reset() override {
+ void
+ invalidate() override
+ {
+ TaggedEntry::invalidate();
address = 0;
secure = false;
streamCounter = 0;
@@ -136,16 +139,20 @@
IndirectPatternDetectorEntry(unsigned int num_addresses,
unsigned int num_shifts)
- : idx1(0), idx2(0), secondIndexSet(false), numMisses(0),
+ : TaggedEntry(), idx1(0), idx2(0), secondIndexSet(false),
+ numMisses(0),
baseAddr(num_addresses, std::vector<Addr>(num_shifts))
- {}
+ {
+ }
- void reset() override {
+ void
+ invalidate() override
+ {
+ TaggedEntry::invalidate();
idx1 = 0;
idx2 = 0;
secondIndexSet = false;
numMisses = 0;
- setInvalid();
}
};
/** Indirect Pattern Detector (IPD) table */
diff --git a/src/mem/cache/prefetch/irregular_stream_buffer.hh b/src/mem/cache/prefetch/irregular_stream_buffer.hh
index c97fde8..fefebc5 100644
--- a/src/mem/cache/prefetch/irregular_stream_buffer.hh
+++ b/src/mem/cache/prefetch/irregular_stream_buffer.hh
@@ -79,13 +79,18 @@
* Maps a set of contiguous addresses to another set of (not necessarily
* contiguos) addresses, with their corresponding confidence counters
*/
- struct AddressMappingEntry : public TaggedEntry {
+ struct AddressMappingEntry : public TaggedEntry
+ {
std::vector<AddressMapping> mappings;
AddressMappingEntry(size_t num_mappings, unsigned counter_bits)
- : mappings(num_mappings, counter_bits)
- {}
- void reset() override
+ : TaggedEntry(), mappings(num_mappings, counter_bits)
{
+ }
+
+ void
+ invalidate() override
+ {
+ TaggedEntry::invalidate();
for (auto &entry : mappings) {
entry.address = 0;
entry.counter.reset();
diff --git a/src/mem/cache/prefetch/signature_path.hh b/src/mem/cache/prefetch/signature_path.hh
index 3bf4dd2..d2464e2 100644
--- a/src/mem/cache/prefetch/signature_path.hh
+++ b/src/mem/cache/prefetch/signature_path.hh
@@ -99,12 +99,16 @@
/** use counter, used by SPPv2 */
SatCounter counter;
PatternEntry(size_t num_strides, unsigned counter_bits)
- : strideEntries(num_strides, counter_bits), counter(counter_bits)
- {}
+ : TaggedEntry(), strideEntries(num_strides, counter_bits),
+ counter(counter_bits)
+ {
+ }
/** Reset the entries to their initial values */
- void reset() override
+ void
+ invalidate() override
{
+ TaggedEntry::invalidate();
for (auto &entry : strideEntries) {
entry.counter.reset();
entry.stride = 0;
diff --git a/src/mem/cache/prefetch/spatio_temporal_memory_streaming.cc b/src/mem/cache/prefetch/spatio_temporal_memory_streaming.cc
index cf6144a..2bcd2fe 100644
--- a/src/mem/cache/prefetch/spatio_temporal_memory_streaming.cc
+++ b/src/mem/cache/prefetch/spatio_temporal_memory_streaming.cc
@@ -96,7 +96,7 @@
// this also sets the values of the entry
pst_entry->update(agt_entry);
// Free the AGT entry
- agt_entry.setInvalid();
+ activeGenerationTable.invalidate(&agt_entry);
}
}
}
diff --git a/src/mem/cache/prefetch/spatio_temporal_memory_streaming.hh b/src/mem/cache/prefetch/spatio_temporal_memory_streaming.hh
index 34cf5d1..725fa38 100644
--- a/src/mem/cache/prefetch/spatio_temporal_memory_streaming.hh
+++ b/src/mem/cache/prefetch/spatio_temporal_memory_streaming.hh
@@ -86,12 +86,16 @@
/** Sequence of accesses */
std::vector<SequenceEntry> sequence;
- ActiveGenerationTableEntry(int num_positions) : paddress(0), pc(0),
+ ActiveGenerationTableEntry(int num_positions)
+ : TaggedEntry(), paddress(0), pc(0),
seqCounter(0), sequence(num_positions)
- {}
-
- void reset() override
{
+ }
+
+ void
+ invalidate() override
+ {
+ TaggedEntry::invalidate();
paddress = 0;
pc = 0;
seqCounter = 0;
