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mem-cache: Implementation of SMS prefetcher (#1454)

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This PR adds the SMS prefetcher described in [this
](https://web.eecs.umich.edu/~twenisch/papers/isca06.pdf) paper.
This work was done in collaboration with @Setu-Gupta, and @xmlizhao

On branch sms
Changes to be committed:
modified: src/mem/cache/prefetch/Prefetcher.py
modified: src/mem/cache/prefetch/SConscript
new file: src/mem/cache/prefetch/sms.cc
new file: src/mem/cache/prefetch/sms.hh

Change-Id: I68d3bb6cf07385177d0f776fb958f652cfc41489
This commit is contained in:
Giacomo Travaglini
2024-10-18 19:15:57 +02:00
committed by GitHub
parent 3fc6cc7763 cf3427f87b
commit 2e271459d0
4 changed files with 263 additions and 2 deletions
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16
src/mem/cache/prefetch/Prefetcher.py vendored
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@@ -599,6 +599,22 @@ class BOPPrefetcher(QueuedPrefetcher):
on_inst = False
class SmsPrefetcher(QueuedPrefetcher):
# Paper: https://web.eecs.umich.edu/~twenisch/papers/isca06.pdf
type = "SmsPrefetcher"
cxx_class = "gem5::prefetch::Sms"
cxx_header = "mem/cache/prefetch/sms.hh"
ft_size = Param.Unsigned(64, "Size of Filter and Active generation table")
pht_size = Param.Unsigned(16384, "Size of pattern history table")
region_size = Param.Unsigned(4096, "Spatial region size")
queue_squash = True
queue_filter = True
cache_snoop = True
prefetch_on_access = True
on_inst = False
class SBOOEPrefetcher(QueuedPrefetcher):
type = "SBOOEPrefetcher"
cxx_class = "gem5::prefetch::SBOOE"

6
src/mem/cache/prefetch/SConscript vendored
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@@ -31,8 +31,9 @@ Import('*')
SimObject('Prefetcher.py', sim_objects=[
'BasePrefetcher', 'MultiPrefetcher', 'QueuedPrefetcher',
'StridePrefetcherHashedSetAssociative', 'StridePrefetcher',
'TaggedPrefetcher', 'IndirectMemoryPrefetcher', 'SignaturePathPrefetcher',
'SignaturePathPrefetcherV2', 'AccessMapPatternMatching', 'AMPMPrefetcher',
'SmsPrefetcher', 'TaggedPrefetcher', 'IndirectMemoryPrefetcher',
'SignaturePathPrefetcher', 'SignaturePathPrefetcherV2',
'AccessMapPatternMatching', 'AMPMPrefetcher',
'DeltaCorrelatingPredictionTables', 'DCPTPrefetcher',
'IrregularStreamBufferPrefetcher', 'SlimAMPMPrefetcher',
'BOPPrefetcher', 'SBOOEPrefetcher', 'STeMSPrefetcher', 'PIFPrefetcher'])
@@ -47,6 +48,7 @@ Source('indirect_memory.cc')
Source('pif.cc')
Source('queued.cc')
Source('sbooe.cc')
Source('sms.cc')
Source('signature_path.cc')
Source('signature_path_v2.cc')
Source('slim_ampm.cc')

161
src/mem/cache/prefetch/sms.cc vendored Normal file
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@@ -0,0 +1,161 @@
/*
* Copyright (c) 2024 Samsung Electronics
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met: redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer;
* redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution;
* neither the name of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/**
* @file
* Describes a SMS prefetcher based on template policies.
*/
#include "mem/cache/prefetch/sms.hh"
#include "debug/HWPrefetch.hh"
#include "params/SmsPrefetcher.hh"
namespace gem5
{
namespace prefetch
{
Sms::Sms(const SmsPrefetcherParams &p)
: Queued(p), Max_Contexts(p.ft_size), MAX_PHTSize(p.pht_size),
Region_Size(p.region_size)
{
AGT.clear();
AGTPC.clear();
FT.clear();
PHT.clear();
fifoFT.clear();
lruAGT.clear();
lruPHT.clear();
}
void
Sms::notifyEvict(const EvictionInfo &info)
{
//Check if any active generation has ended
Addr region_base = roundDown(info.addr, Region_Size);
std::pair <Addr,Addr> pc_offset = AGTPC[region_base];
if (AGT.find(region_base) != AGT.end()) {
//remove old recording
if (PHT.find(pc_offset) != PHT.end()) {
PHT[pc_offset].clear();
}
//Move from AGT to PHT
for (std::set<Addr>::iterator it = AGT[region_base].begin();
it != AGT[region_base].end(); it ++) {
PHT[pc_offset].insert(*it);
}
lruPHT.push_front(pc_offset);
}
while (PHT.size() > MAX_PHTSize) {
PHT.erase(lruPHT.back());
lruPHT.pop_back();
}
AGTPC.erase(region_base);
AGT.erase(region_base);
}
void
Sms::calculatePrefetch(const PrefetchInfo &pfi,
std::vector<AddrPriority> &addresses,
const CacheAccessor &cache)
{
if (!pfi.hasPC()) {
DPRINTF(HWPrefetch, "Ignoring request with no PC.\n");
return;
}
Addr blk_addr = blockAddress(pfi.getAddr());
Addr pc = pfi.getPC();
Addr region_base = roundDown(blk_addr, Region_Size);
Addr offset = blk_addr - region_base;
//Training
if (AGT.find(region_base) != AGT.end()) {
assert (FT.find(region_base) == FT.end());
// Record Pattern
AGT[region_base].insert(offset);
//update LRU
for (std::deque <Addr>::iterator lit = lruAGT.begin();
lit != lruAGT.end(); lit ++) {
if ((*lit) == region_base) {
lruAGT.erase(lit);
lruAGT.push_front(region_base);
break;
}
}
} else if (FT.find(region_base) != FT.end()) {
//move entry from FT to AGT
AGT[region_base].insert(FT[region_base].second);
AGTPC[region_base] = FT[region_base];
lruAGT.push_front(region_base);
//Record latest offset
AGT[region_base].insert(offset);
//Recycle FT entry
FT.erase(region_base);
//Make space for next entry
while (AGT.size() > Max_Contexts) {
AGT.erase(lruAGT.back());
AGTPC.erase(lruAGT.back());
lruAGT.pop_back();
}
} else {
// Trigger Access
FT[region_base] = std::make_pair (pc,offset);
fifoFT.push_front(region_base);
while (FT.size() > Max_Contexts) {
FT.erase(fifoFT.back());
fifoFT.pop_back();
}
}
//Prediction
std::pair <Addr, Addr> pc_offset = std::make_pair(pc,offset);
if (PHT.find(pc_offset) != PHT.end()) {
for (std::set<Addr>::iterator it = PHT[pc_offset].begin();
it != PHT[pc_offset].end(); it ++) {
Addr pref_addr = blockAddress(region_base + (*it));
addresses.push_back(AddrPriority(pref_addr,0));
}
for (std::deque < std::pair <Addr,Addr> >::iterator lit
= lruPHT.begin(); lit != lruPHT.end(); lit ++) {
if ((*lit) == pc_offset) {
lruPHT.erase(lit);
lruPHT.push_front(pc_offset);
break;
}
}
}
}
} // namespace prefetch
} // namespace gem5

82
src/mem/cache/prefetch/sms.hh vendored Normal file
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@@ -0,0 +1,82 @@
/*
* Copyright (c) 2024 Samsung Electronics
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met: redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer;
* redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution;
* neither the name of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/**
* @file
* Describes a SMS prefetcher.
*/
#ifndef __MEM_CACHE_PREFETCH_SMS_HH__
#define __MEM_CACHE_PREFETCH_SMS_HH__
#include <set>
#include "mem/cache/prefetch/queued.hh"
#include "mem/packet.hh"
namespace gem5
{
struct SmsPrefetcherParams;
namespace prefetch
{
class Sms : public Queued
{
private:
const int Max_Contexts; //= 64;
const uint64_t MAX_PHTSize; //= 512;
const Addr Region_Size; //= 4096;
std::map< Addr, std::set<Addr> > AGT;
std::map< Addr, std::pair<Addr,Addr> > AGTPC;
std::map< Addr, std::pair<Addr,Addr> > FT;
std::map< std::pair <Addr,Addr> , std::set<Addr> > PHT;
std::deque<Addr> fifoFT;
std::deque<Addr> lruAGT;
std::deque< std::pair <Addr,Addr> > lruPHT;
using EvictionInfo = CacheDataUpdateProbeArg;
void notifyEvict(const EvictionInfo &info) override;
public:
Sms(const SmsPrefetcherParams &p);
~Sms() = default;
void calculatePrefetch(const PrefetchInfo &pfi,
std::vector<AddrPriority> &addresses,
const CacheAccessor &cache) override;
};
} // namespace prefetch
} // namespace gem5
#endif // __MEM_CACHE_PREFETCH_SMS_HH__