From 93e283abb348b81d086225f7861d94901c9b0888 Mon Sep 17 00:00:00 2001 From: Nilay Vaish Date: Tue, 11 Dec 2012 10:05:54 -0600 Subject: ruby: add a prefetcher This patch adds a prefetcher for the ruby memory system. The prefetcher is based on a prefetcher implemented by others (well, I don't know who wrote the original). The prefetcher does stride-based prefetching, both unit and non-unit. It obseves the misses in the cache and trains on these. After the training period is over, the prefetcher starts issuing prefetch requests to the controller. --- src/mem/SConscript | 4 +- src/mem/ruby/SConscript | 1 + src/mem/ruby/slicc_interface/AbstractController.hh | 4 + src/mem/ruby/structures/Prefetcher.cc | 469 +++++++++++++++++++++ src/mem/ruby/structures/Prefetcher.hh | 210 +++++++++ src/mem/ruby/structures/RubyPrefetcher.py | 47 +++ src/mem/ruby/structures/SConscript | 37 ++ 7 files changed, 771 insertions(+), 1 deletion(-) create mode 100644 src/mem/ruby/structures/Prefetcher.cc create mode 100644 src/mem/ruby/structures/Prefetcher.hh create mode 100644 src/mem/ruby/structures/RubyPrefetcher.py create mode 100644 src/mem/ruby/structures/SConscript (limited to 'src') diff --git a/src/mem/SConscript b/src/mem/SConscript index 9cf8b08d1..374f904a8 100644 --- a/src/mem/SConscript +++ b/src/mem/SConscript @@ -86,6 +86,7 @@ DebugFlag('RubyGenerated') DebugFlag('RubyMemory') DebugFlag('RubyNetwork') DebugFlag('RubyPort') +DebugFlag('RubyPrefetcher') DebugFlag('RubyQueue') DebugFlag('RubySequencer') DebugFlag('RubySlicc') @@ -96,4 +97,5 @@ DebugFlag('RubyResourceStalls') CompoundFlag('Ruby', [ 'RubyQueue', 'RubyNetwork', 'RubyTester', 'RubyGenerated', 'RubySlicc', 'RubySystem', 'RubyCache', - 'RubyMemory', 'RubyDma', 'RubyPort', 'RubySequencer', 'RubyCacheTrace']) + 'RubyMemory', 'RubyDma', 'RubyPort', 'RubySequencer', 'RubyCacheTrace', + 'RubyPrefetcher']) diff --git a/src/mem/ruby/SConscript b/src/mem/ruby/SConscript index 06f6abd9f..086c2f764 100644 --- a/src/mem/ruby/SConscript +++ b/src/mem/ruby/SConscript @@ -103,6 +103,7 @@ MakeInclude('common/DataBlock.hh') MakeInclude('common/NetDest.hh') MakeInclude('common/Set.hh') MakeInclude('filters/GenericBloomFilter.hh') +MakeInclude('structures/Prefetcher.hh') MakeInclude('system/CacheMemory.hh') MakeInclude('system/DMASequencer.hh') MakeInclude('system/DirectoryMemory.hh') diff --git a/src/mem/ruby/slicc_interface/AbstractController.hh b/src/mem/ruby/slicc_interface/AbstractController.hh index c5cb46f1e..9ab924608 100644 --- a/src/mem/ruby/slicc_interface/AbstractController.hh +++ b/src/mem/ruby/slicc_interface/AbstractController.hh @@ -78,6 +78,10 @@ class AbstractController : public SimObject, public Consumer //! The return value indicates the number of messages written with the //! data from the packet. virtual uint32_t functionalWriteBuffers(PacketPtr&) = 0; + + //! Function for enqueuing a prefetch request + virtual void enqueuePrefetch(const Address&, const RubyRequestType&) + { fatal("Prefetches not implemented!");} }; #endif // __MEM_RUBY_SLICC_INTERFACE_ABSTRACTCONTROLLER_HH__ diff --git a/src/mem/ruby/structures/Prefetcher.cc b/src/mem/ruby/structures/Prefetcher.cc new file mode 100644 index 000000000..5135c2bb2 --- /dev/null +++ b/src/mem/ruby/structures/Prefetcher.cc @@ -0,0 +1,469 @@ +/* + * Copyright (c) 1999-2012 Mark D. Hill and David A. Wood + * 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. + */ + +#include "debug/RubyPrefetcher.hh" +#include "mem/ruby/slicc_interface/RubySlicc_ComponentMapping.hh" +#include "mem/ruby/structures/Prefetcher.hh" +#include "mem/ruby/system/System.hh" + +Prefetcher* +PrefetcherParams::create() +{ + return new Prefetcher(this); +} + +Prefetcher::Prefetcher(const Params *p) + : SimObject(p), m_num_streams(p->num_streams), + m_array(p->num_streams), m_train_misses(p->train_misses), + m_num_startup_pfs(p->num_startup_pfs), m_num_unit_filters(p->unit_filter), + m_num_nonunit_filters(p->nonunit_filter), + m_unit_filter(p->unit_filter, Address(0)), + m_negative_filter(p->unit_filter, Address(0)), + m_nonunit_filter(p->nonunit_filter, Address(0)), + m_prefetch_cross_pages(p->cross_page) +{ + assert(m_num_streams > 0); + assert(m_num_startup_pfs <= MAX_PF_INFLIGHT); + + // create +1 stride filter + m_unit_filter_index = 0; + m_unit_filter_hit = new uint32_t[m_num_unit_filters]; + for (uint32_t i =0; i < m_num_unit_filters; i++) { + m_unit_filter_hit[i] = 0; + } + + // create -1 stride filter + m_negative_filter_index = 0; + m_negative_filter_hit = new uint32_t[m_num_unit_filters]; + for (int i =0; i < m_num_unit_filters; i++) { + m_negative_filter_hit[i] = 0; + } + + // create nonunit stride filter + m_nonunit_index = 0; + m_nonunit_stride = new int[m_num_nonunit_filters]; + m_nonunit_hit = new uint32_t[m_num_nonunit_filters]; + for (int i =0; i < m_num_nonunit_filters; i++) { + m_nonunit_stride[i] = 0; + m_nonunit_hit[i] = 0; + } +} + +Prefetcher::~Prefetcher() +{ + delete m_unit_filter_hit; + delete m_negative_filter_hit; + delete m_nonunit_stride; + delete m_nonunit_hit; +} + +void +Prefetcher::regStats() +{ + numMissObserved + .name(name() + ".miss_observed") + .desc("number of misses observed") + ; + + numAllocatedStreams + .name(name() + ".allocated_streams") + .desc("number of streams allocated for prefetching") + ; + + numPrefetchRequested + .name(name() + ".prefetches_requested") + .desc("number of prefetch requests made") + ; + + numPrefetchAccepted + .name(name() + ".prefetches_accepted") + .desc("number of prefetch requests accepted") + ; + + numDroppedPrefetches + .name(name() + ".dropped_prefetches") + .desc("number of prefetch requests dropped") + ; + + numHits + .name(name() + ".hits") + .desc("number of prefetched blocks accessed") + ; + + numPartialHits + .name(name() + ".partial_hits") + .desc("number of misses observed for a block being prefetched") + ; + + numPagesCrossed + .name(name() + ".pages_crossed") + .desc("number of prefetches across pages") + ; + + numMissedPrefetchedBlocks + .name(name() + ".misses_on_prefetched_blocks") + .desc("number of misses for blocks that were prefetched, yet missed") + ; +} + +void +Prefetcher::observeMiss(const Address& address, const RubyRequestType& type) +{ + DPRINTF(RubyPrefetcher, "Observed miss for %s\n", address); + Address line_addr = line_address(address); + numMissObserved++; + + // check to see if we have already issued a prefetch for this block + uint32_t index = 0; + PrefetchEntry *pfEntry = getPrefetchEntry(line_addr, index); + if (pfEntry != NULL) { + if (pfEntry->requestIssued[index]) { + if (pfEntry->requestCompleted[index]) { + // We prefetched too early and now the prefetch block no + // longer exists in the cache + numMissedPrefetchedBlocks++; + return; + } else { + // The controller has issued the prefetch request, + // but the request for the block arrived earlier. + numPartialHits++; + observePfHit(line_addr); + return; + } + } else { + // The request is still in the prefetch queue of the controller. + // Or was evicted because of other requests. + return; + } + } + + // check to see if this address is in the unit stride filter + bool alloc = false; + bool hit = accessUnitFilter(m_unit_filter, m_unit_filter_hit, + m_unit_filter_index, line_addr, 1, alloc); + if (alloc) { + // allocate a new prefetch stream + initializeStream(line_addr, 1, getLRUindex(), type); + } + if (hit) { + DPRINTF(RubyPrefetcher, " *** hit in unit stride buffer\n"); + return; + } + + hit = accessUnitFilter(m_negative_filter, m_negative_filter_hit, + m_negative_filter_index, line_addr, -1, alloc); + if (alloc) { + // allocate a new prefetch stream + initializeStream(line_addr, -1, getLRUindex(), type); + } + if (hit) { + DPRINTF(RubyPrefetcher, " *** hit in unit negative unit buffer\n"); + return; + } + + // check to see if this address is in the non-unit stride filter + int stride = 0; // NULL value + hit = accessNonunitFilter(address, &stride, alloc); + if (alloc) { + assert(stride != 0); // ensure non-zero stride prefetches + initializeStream(line_addr, stride, getLRUindex(), type); + } + if (hit) { + DPRINTF(RubyPrefetcher, " *** hit in non-unit stride buffer\n"); + return; + } +} + +void +Prefetcher::observePfMiss(const Address& address) +{ + numPartialHits++; + DPRINTF(RubyPrefetcher, "Observed partial hit for %s\n", address); + issueNextPrefetch(address, NULL); +} + +void +Prefetcher::observePfHit(const Address& address) +{ + numHits++; + DPRINTF(RubyPrefetcher, "Observed hit for %s\n", address); + issueNextPrefetch(address, NULL); +} + +void +Prefetcher::issueNextPrefetch(const Address &address, PrefetchEntry *stream) +{ + // get our corresponding stream fetcher + if (stream == NULL) { + uint32_t index = 0; + stream = getPrefetchEntry(address, index); + } + + // if (for some reason), this stream is unallocated, return. + if (stream == NULL) { + DPRINTF(RubyPrefetcher, "Unallocated stream, returning\n"); + return; + } + + // extend this prefetching stream by 1 (or more) + Address page_addr = page_address(stream->m_address); + Address line_addr = next_stride_address(stream->m_address, + stream->m_stride); + + // possibly stop prefetching at page boundaries + if (page_addr != page_address(line_addr)) { + numPagesCrossed++; + if (!m_prefetch_cross_pages) { + // Deallocate the stream since we are not prefetching + // across page boundries + stream->m_is_valid = false; + return; + } + } + + // launch next prefetch + stream->m_address = line_addr; + stream->m_use_time = g_system_ptr->getTime(); + DPRINTF(RubyPrefetcher, "Requesting prefetch for %s\n", line_addr); + m_controller->enqueuePrefetch(line_addr, stream->m_type); +} + +uint32_t +Prefetcher::getLRUindex(void) +{ + uint32_t lru_index = 0; + Time lru_access = m_array[lru_index].m_use_time; + + for (uint32_t i = 0; i < m_num_streams; i++) { + if (!m_array[i].m_is_valid) { + return i; + } + if (m_array[i].m_use_time < lru_access) { + lru_access = m_array[i].m_use_time; + lru_index = i; + } + } + + return lru_index; +} + +void +Prefetcher::clearNonunitEntry(uint32_t index) +{ + m_nonunit_filter[index].setAddress(0); + m_nonunit_stride[index] = 0; + m_nonunit_hit[index] = 0; +} + +void +Prefetcher::initializeStream(const Address& address, int stride, + uint32_t index, const RubyRequestType& type) +{ + numAllocatedStreams++; + + // initialize the stream prefetcher + PrefetchEntry *mystream = &(m_array[index]); + mystream->m_address = line_address(address); + mystream->m_stride = stride; + mystream->m_use_time = g_system_ptr->getTime(); + mystream->m_is_valid = true; + mystream->m_type = type; + + // create a number of initial prefetches for this stream + Address page_addr = page_address(mystream->m_address); + Address line_addr = line_address(mystream->m_address); + Address prev_addr = line_addr; + + // insert a number of prefetches into the prefetch table + for (int k = 0; k < m_num_startup_pfs; k++) { + line_addr = next_stride_address(line_addr, stride); + // possibly stop prefetching at page boundaries + if (page_addr != page_address(line_addr)) { + numPagesCrossed++; + if (!m_prefetch_cross_pages) { + // deallocate this stream prefetcher + mystream->m_is_valid = false; + return; + } + } + + // launch prefetch + numPrefetchRequested++; + DPRINTF(RubyPrefetcher, "Requesting prefetch for %s\n", line_addr); + m_controller->enqueuePrefetch(line_addr, m_array[index].m_type); + prev_addr = line_addr; + } + + // update the address to be the last address prefetched + mystream->m_address = line_addr; +} + +PrefetchEntry * +Prefetcher::getPrefetchEntry(const Address &address, uint32_t &index) +{ + // search all streams for a match + for (int i = 0; i < m_num_streams; i++) { + // search all the outstanding prefetches for this stream + if (m_array[i].m_is_valid) { + for (int j = 0; j < m_num_startup_pfs; j++) { + if (next_stride_address(m_array[i].m_address, + -(m_array[i].m_stride*j)) == address) { + return &(m_array[i]); + } + } + } + } + return NULL; +} + +bool +Prefetcher::accessUnitFilter(std::vector
& filter_table, + uint32_t *filter_hit, uint32_t &index, const Address &address, + int stride, bool &alloc) +{ + //reset the alloc flag + alloc = false; + + Address line_addr = line_address(address); + for (int i = 0; i < m_num_unit_filters; i++) { + if (filter_table[i] == line_addr) { + filter_table[i] = next_stride_address(filter_table[i], stride); + filter_hit[i]++; + if (filter_hit[i] >= m_train_misses) { + alloc = true; + } + return true; + } + } + + // enter this address in the table + int local_index = index; + filter_table[local_index] = next_stride_address(line_addr, stride); + filter_hit[local_index] = 0; + local_index = local_index + 1; + if (local_index >= m_num_unit_filters) { + local_index = 0; + } + + index = local_index; + return false; +} + +bool +Prefetcher::accessNonunitFilter(const Address& address, int *stride, + bool &alloc) +{ + //reset the alloc flag + alloc = false; + + /// look for non-unit strides based on a (user-defined) page size + Address page_addr = page_address(address); + Address line_addr = line_address(address); + + for (uint32_t i = 0; i < m_num_nonunit_filters; i++) { + if (page_address(m_nonunit_filter[i]) == page_addr) { + // hit in the non-unit filter + // compute the actual stride (for this reference) + int delta = line_addr.getAddress() - m_nonunit_filter[i].getAddress(); + + if (delta != 0) { + // no zero stride prefetches + // check that the stride matches (for the last N times) + if (delta == m_nonunit_stride[i]) { + // -> stride hit + // increment count (if > 2) allocate stream + m_nonunit_hit[i]++; + if (m_nonunit_hit[i] > m_train_misses) { + //This stride HAS to be the multiplicative constant of + //dataBlockBytes (bc next_stride_address is calculated based + //on this multiplicative constant!) + *stride = m_nonunit_stride[i]/RubySystem::getBlockSizeBytes(); + + // clear this filter entry + clearNonunitEntry(i); + alloc = true; + } + } else { + // delta didn't match ... reset m_nonunit_hit count for this entry + m_nonunit_hit[i] = 0; + } + + // update the last address seen & the stride + m_nonunit_stride[i] = delta; + m_nonunit_filter[i] = line_addr; + return true; + } else { + return false; + } + } + } + + // not found: enter this address in the table + m_nonunit_filter[m_nonunit_index] = line_addr; + m_nonunit_stride[m_nonunit_index] = 0; + m_nonunit_hit[m_nonunit_index] = 0; + + m_nonunit_index = m_nonunit_index + 1; + if (m_nonunit_index >= m_num_nonunit_filters) { + m_nonunit_index = 0; + } + return false; +} + +void +Prefetcher::print(std::ostream& out) const +{ + out << name() << " Prefetcher State\n"; + // print out unit filter + out << "unit table:\n"; + for (int i = 0; i < m_num_unit_filters; i++) { + out << m_unit_filter[i] << std::endl; + } + + out << "negative table:\n"; + for (int i = 0; i < m_num_unit_filters; i++) { + out << m_negative_filter[i] << std::endl; + } + + // print out non-unit stride filter + out << "non-unit table:\n"; + for (int i = 0; i < m_num_nonunit_filters; i++) { + out << m_nonunit_filter[i] << " " + << m_nonunit_stride[i] << " " + << m_nonunit_hit[i] << std::endl; + } + + // print out allocated stream buffers + out << "streams:\n"; + for (int i = 0; i < m_num_streams; i++) { + out << m_array[i].m_address << " " + << m_array[i].m_stride << " " + << m_array[i].m_is_valid << " " + << m_array[i].m_use_time << std::endl; + } +} diff --git a/src/mem/ruby/structures/Prefetcher.hh b/src/mem/ruby/structures/Prefetcher.hh new file mode 100644 index 000000000..f64d39f8a --- /dev/null +++ b/src/mem/ruby/structures/Prefetcher.hh @@ -0,0 +1,210 @@ +/* + * Copyright (c) 1999-2012 Mark D. Hill and David A. Wood + * 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. + */ + +#ifndef PREFETCHER_H +#define PREFETCHER_H + +// Implements Power 4 like prefetching + +#include + +#include "base/statistics.hh" +#include "mem/ruby/buffers/MessageBuffer.hh" +#include "mem/ruby/common/Address.hh" +#include "mem/ruby/common/Global.hh" +#include "mem/ruby/slicc_interface/AbstractController.hh" +#include "mem/ruby/slicc_interface/RubyRequest.hh" +#include "params/Prefetcher.hh" +#include "sim/sim_object.hh" + +#define MAX_PF_INFLIGHT 8 + +class PrefetchEntry +{ + public: + /// constructor + PrefetchEntry() + { + // default: 1 cache-line stride + m_stride = (1 << RubySystem::getBlockSizeBits()); + m_use_time = Cycles(0); + m_is_valid = false; + } + + //! The base address for the stream prefetch + Address m_address; + + //! stride distance to get next address from + int m_stride; + + //! the last time that any prefetched request was used + Cycles m_use_time; + + //! valid bit for each stream + bool m_is_valid; + + //! L1D prefetches loads and stores + RubyRequestType m_type; + + //! Bitset for tracking prefetches for which addresses have been + //! issued, which ones have completed. + std::bitset requestIssued; + std::bitset requestCompleted; +}; + +class Prefetcher : public SimObject +{ + public: + typedef PrefetcherParams Params; + Prefetcher(const Params *p); + ~Prefetcher(); + + void issueNextPrefetch(const Address &address, PrefetchEntry *stream); + /** + * Implement the prefetch hit(miss) callback interface. + * These functions are called by the cache when it hits(misses) + * on a line with the line's prefetch bit set. If this address + * hits in m_array we will continue prefetching the stream. + */ + void observePfHit(const Address& address); + void observePfMiss(const Address& address); + + /** + * Observe a memory miss from the cache. + * + * @param address The physical address that missed out of the cache. + */ + void observeMiss(const Address& address, const RubyRequestType& type); + + /** + * Print out some statistics + */ + void print(std::ostream& out) const; + void setController(AbstractController *_ctrl) + { m_controller = _ctrl; } + + void regStats(); + + private: + /** + * Returns an unused stream buffer (or if all are used, returns the + * least recently used (accessed) stream buffer). + * @return The index of the least recently used stream buffer. + */ + uint32_t getLRUindex(void); + + //! clear a non-unit stride prefetcher entry + void clearNonunitEntry(uint32_t index); + + //! allocate a new stream buffer at a specific index + void initializeStream(const Address& address, int stride, + uint32_t index, const RubyRequestType& type); + + //! get pointer to the matching stream entry, returns NULL if not found + //! index holds the multiple of the stride this address is. + PrefetchEntry* getPrefetchEntry(const Address &address, + uint32_t &index); + + /// access a unit stride filter to determine if there is a hit + bool accessUnitFilter(std::vector
& filter_table, + uint32_t *hit_table, uint32_t &index, const Address &address, + int stride, bool &alloc); + + /// access a unit stride filter to determine if there is a hit + bool accessNonunitFilter(const Address& address, int *stride, + bool &alloc); + + //! number of prefetch streams available + uint32_t m_num_streams; + //! an array of the active prefetch streams + std::vector m_array; + + //! number of misses I must see before allocating a stream + uint32_t m_train_misses; + //! number of initial prefetches to startup a stream + uint32_t m_num_startup_pfs; + //! number of stride filters + uint32_t m_num_unit_filters; + //! number of non-stride filters + uint32_t m_num_nonunit_filters; + + /// a unit stride filter array: helps reduce BW requirement of + /// prefetching + std::vector
m_unit_filter; + /// a round robin pointer into the unit filter group + uint32_t m_unit_filter_index; + //! An array used to count the of times particular filter entries + //! have been hit + uint32_t *m_unit_filter_hit; + + //! a negative nit stride filter array: helps reduce BW requirement + //! of prefetching + std::vector
m_negative_filter; + /// a round robin pointer into the negative filter group + uint32_t m_negative_filter_index; + /// An array used to count the of times particular filter entries + /// have been hit + uint32_t *m_negative_filter_hit; + + /// a non-unit stride filter array: helps reduce BW requirement of + /// prefetching + std::vector
m_nonunit_filter; + /// An array of strides (in # of cache lines) for the filter entries + int *m_nonunit_stride; + /// An array used to count the of times particular filter entries + /// have been hit + uint32_t *m_nonunit_hit; + /// a round robin pointer into the unit filter group + uint32_t m_nonunit_index; + + /// Used for allowing prefetches across pages. + bool m_prefetch_cross_pages; + + AbstractController *m_controller; + + //! Count of accesses to the prefetcher + Stats::Scalar numMissObserved; + //! Count of prefetch streams allocated + Stats::Scalar numAllocatedStreams; + //! Count of prefetch requests made + Stats::Scalar numPrefetchRequested; + //! Count of prefetch requests accepted + Stats::Scalar numPrefetchAccepted; + //! Count of prefetches dropped + Stats::Scalar numDroppedPrefetches; + //! Count of successful prefetches + Stats::Scalar numHits; + //! Count of partial successful prefetches + Stats::Scalar numPartialHits; + //! Count of pages crossed + Stats::Scalar numPagesCrossed; + //! Count of misses incurred for blocks that were prefetched + Stats::Scalar numMissedPrefetchedBlocks; +}; + +#endif // PREFETCHER_H diff --git a/src/mem/ruby/structures/RubyPrefetcher.py b/src/mem/ruby/structures/RubyPrefetcher.py new file mode 100644 index 000000000..a02b11696 --- /dev/null +++ b/src/mem/ruby/structures/RubyPrefetcher.py @@ -0,0 +1,47 @@ +# Copyright (c) 2012 Mark D. Hill and David A. Wood +# 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. +# +# Authors: Nilay Vaish + +from m5.SimObject import SimObject +from m5.params import * + +class Prefetcher(SimObject): + type = 'Prefetcher' + cxx_class = 'Prefetcher' + cxx_header = "mem/ruby/structures/Prefetcher.hh" + + num_streams = Param.UInt32(4, + "Number of prefetch streams to be allocated") + pf_per_stream = Param.UInt32(1, "Number of prefetches per stream") + unit_filter = Param.UInt32(8, + "Number of entries in the unit filter array") + nonunit_filter = Param.UInt32(8, + "Number of entries in the non-unit filter array") + train_misses = Param.UInt32(4, "") + num_startup_pfs = Param.UInt32(1, "") + cross_page = Param.Bool(False, """True if prefetched address can be on a + page different from the observed address""") diff --git a/src/mem/ruby/structures/SConscript b/src/mem/ruby/structures/SConscript new file mode 100644 index 000000000..170f61e88 --- /dev/null +++ b/src/mem/ruby/structures/SConscript @@ -0,0 +1,37 @@ +# -*- mode:python -*- + +# Copyright (c) 2012 Mark D. Hill and David A. Wood +# 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. +# +# Authors: Nilay Vaish + +Import('*') + +if env['PROTOCOL'] == 'None': + Return() + +SimObject('RubyPrefetcher.py') +Source('Prefetcher.cc') -- cgit v1.2.3