Daniel Carvalho has uploaded this change for review. (
https://gem5-review.googlesource.com/c/public/gem5/+/18869
Change subject: mem-ruby: Make MultiGrainBloomFilter generic
......................................................................
mem-ruby: Make MultiGrainBloomFilter generic
Allow combining any number of Bloom Filters in the MultiGrain.
Change-Id: I73ae33063e1feed731af6f625d2f64245f21df18
Signed-off-by: Daniel R. Carvalho <[email protected]>
---
M src/mem/ruby/filters/BloomFilters.py
M src/mem/ruby/filters/MultiGrainBloomFilter.cc
M src/mem/ruby/filters/MultiGrainBloomFilter.hh
3 files changed, 57 insertions(+), 48 deletions(-)
diff --git a/src/mem/ruby/filters/BloomFilters.py
b/src/mem/ruby/filters/BloomFilters.py
index e413e2f..2ec671d 100644
--- a/src/mem/ruby/filters/BloomFilters.py
+++ b/src/mem/ruby/filters/BloomFilters.py
@@ -88,10 +88,21 @@
cxx_class = 'MultiGrainBloomFilter'
cxx_header = "mem/ruby/filters/MultiGrainBloomFilter.hh"
+ # The base filter should not be used, since this filter is the
combination
+ # of multiple sub-filters
+ size = 0
+
+ # These should be set together. By default there are two sub-filters
that
+ # hash sequential bitfields
+ num_filters = Param.Int(2, "Number of sub-filters")
+ filters = VectorParam.AbstractBloomFilter([
+ BlockBloomFilter(size = 4096, offset_lsb = 6),
+ BlockBloomFilter(size = 1024, offset_lsb = 18)],
+ "Sub-filters to be combined")
+
# This is the maximum value achievable of the sum of the hashed
respective
- # entry of the two filters
- threshold = 2
- page_filter_size = Param.Int(1024, "Number of entries in the page
filter")
+ # entry of all sub filters
+ threshold = Self.num_filters
class NonCountingBloomFilter(AbstractBloomFilter):
type = 'NonCountingBloomFilter'
diff --git a/src/mem/ruby/filters/MultiGrainBloomFilter.cc
b/src/mem/ruby/filters/MultiGrainBloomFilter.cc
index 903bad2..e1db66e 100644
--- a/src/mem/ruby/filters/MultiGrainBloomFilter.cc
+++ b/src/mem/ruby/filters/MultiGrainBloomFilter.cc
@@ -28,14 +28,15 @@
#include "mem/ruby/filters/MultiGrainBloomFilter.hh"
-#include "base/bitfield.hh"
+#include "base/logging.hh"
#include "params/MultiGrainBloomFilter.hh"
MultiGrainBloomFilter::MultiGrainBloomFilter(
const MultiGrainBloomFilterParams* p)
- : AbstractBloomFilter(p), pageFilter(p->page_filter_size),
- pageFilterSizeBits(floorLog2(p->page_filter_size))
+ : AbstractBloomFilter(p), filters(p->filters)
{
+ fatal_if(p->num_filters != filters.size(), "The number of filters " \
+ "should match the number of filters provided");
}
MultiGrainBloomFilter::~MultiGrainBloomFilter()
@@ -45,62 +46,57 @@
void
MultiGrainBloomFilter::clear()
{
- AbstractBloomFilter::clear();
- for (auto& entry : pageFilter){
- entry = 0;
+ for (auto& sub_filter : filters) {
+ sub_filter->clear();
+ }
+}
+
+void
+MultiGrainBloomFilter::merge(const AbstractBloomFilter* other)
+{
+ auto* cast_other = static_cast<const MultiGrainBloomFilter*>(other);
+ assert(filters.size() == cast_other->filters.size());
+ for (int i = 0; i < filters.size(); ++i){
+ filters[i]->merge(cast_other->filters[i]);
}
}
void
MultiGrainBloomFilter::set(Addr addr)
{
- const int index = hash(addr);
- assert(index < filter.size());
- filter[index] = 1;
+ for (auto& sub_filter : filters) {
+ sub_filter->set(addr);
+ }
+}
- const int page_index = pageHash(addr);
- assert(page_index < pageFilter.size());
- pageFilter[page_index] = 1;
+void
+MultiGrainBloomFilter::unset(Addr addr)
+{
+ for (auto& sub_filter : filters) {
+ sub_filter->unset(addr);
+ }
}
int
MultiGrainBloomFilter::getCount(Addr addr) const
{
- const int index = hash(addr);
- const int page_index = pageHash(addr);
- assert(index < filter.size());
- assert(page_index < pageFilter.size());
- return filter[index] + pageFilter[page_index];
+ int count = 0;
+ for (const auto& sub_filter : filters) {
+ count += sub_filter->getCount(addr);
+ }
+ return count;
}
int
MultiGrainBloomFilter::getTotalCount() const
{
- int count = AbstractBloomFilter::getTotalCount();
-
- for (const auto& entry : pageFilter) {
- count += entry;
+ int count = 0;
+ for (const auto& sub_filter : filters) {
+ count += sub_filter->getTotalCount();
}
-
return count;
}
-int
-MultiGrainBloomFilter::hash(Addr addr) const
-{
- // grap a chunk of bits after byte offset
- return bits(addr, blkBits + sizeBits - 1, blkBits);
-}
-
-int
-MultiGrainBloomFilter::pageHash(Addr addr) const
-{
- int num_bits = blkBits + sizeBits - 1;
-
- // grap a chunk of bits after first chunk
- return bits(addr, num_bits + pageFilterSizeBits - 1, num_bits);
-}
-
MultiGrainBloomFilter*
MultiGrainBloomFilterParams::create()
{
diff --git a/src/mem/ruby/filters/MultiGrainBloomFilter.hh
b/src/mem/ruby/filters/MultiGrainBloomFilter.hh
index e895788..04c375e 100644
--- a/src/mem/ruby/filters/MultiGrainBloomFilter.hh
+++ b/src/mem/ruby/filters/MultiGrainBloomFilter.hh
@@ -35,6 +35,11 @@
struct MultiGrainBloomFilterParams;
+/**
+ * This BloomFilter has multiple sub-filters, each with its own hashing
+ * functionality. The results of the operations are the results of applying
+ * them to each sub-filter.
+ */
class MultiGrainBloomFilter : public AbstractBloomFilter
{
public:
@@ -43,18 +48,15 @@
void clear() override;
void set(Addr addr) override;
+ void unset(Addr addr) override;
+ void merge(const AbstractBloomFilter* other) override;
int getCount(Addr addr) const override;
int getTotalCount() const override;
private:
- int hash(Addr addr) const;
- int pageHash(Addr addr) const;
-
- // The block filter uses the filter vector declared in the base class
- /** The page number filter. */
- std::vector<int> pageFilter;
- int pageFilterSizeBits;
+ /** Sub-filters used by this filter. */
+ std::vector<AbstractBloomFilter*> filters;
};
#endif // __MEM_RUBY_FILTERS_MULTIGRAINBLOOMFILTER_HH__
--
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Gerrit-Project: public/gem5
Gerrit-Branch: master
Gerrit-Change-Id: I73ae33063e1feed731af6f625d2f64245f21df18
Gerrit-Change-Number: 18869
Gerrit-PatchSet: 1
Gerrit-Owner: Daniel Carvalho <[email protected]>
Gerrit-MessageType: newchange
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