src/mem/cache/prefetch/Prefetcher.py - testing/jenkins-gem5-prod - Git at Google

 # Copyright (c) 2012, 2014 ARM Limited
 # All rights reserved.
 #
 # The license below extends only to copyright in the software and shall
 # not be construed as granting a license to any other intellectual
 # property including but not limited to intellectual property relating
 # to a hardware implementation of the functionality of the software
 # licensed hereunder.  You may use the software subject to the license
 # terms below provided that you ensure that this notice is replicated
 # unmodified and in its entirety in all distributions of the software,
 # modified or unmodified, in source code or in binary form.
 #
 # Copyright (c) 2005 The Regents of The University of Michigan
 # 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: Ron Dreslinski
 #          Mitch Hayenga

 from ClockedObject import ClockedObject
 from IndexingPolicies import *
 from m5.SimObject import *
 from m5.params import *
 from m5.proxy import *
 from ReplacementPolicies import *

 class HWPProbeEvent(object):
     def __init__(self, prefetcher, obj, *listOfNames):
         self.obj = obj
         self.prefetcher = prefetcher
         self.names = listOfNames

     def register(self):
         if self.obj:
             for name in self.names:
                 self.prefetcher.getCCObject().addEventProbe(
                     self.obj.getCCObject(), name)

 class BasePrefetcher(ClockedObject):
     type = 'BasePrefetcher'
     abstract = True
     cxx_header = "mem/cache/prefetch/base.hh"
     cxx_exports = [
         PyBindMethod("addEventProbe"),
     ]
     sys = Param.System(Parent.any, "System this prefetcher belongs to")

     # Get the block size from the parent (system)
     block_size = Param.Int(Parent.cache_line_size, "Block size in bytes")

     on_miss = Param.Bool(False, "Only notify prefetcher on misses")
     on_read = Param.Bool(True, "Notify prefetcher on reads")
     on_write = Param.Bool(True, "Notify prefetcher on writes")
     on_data  = Param.Bool(True, "Notify prefetcher on data accesses")
     on_inst  = Param.Bool(True, "Notify prefetcher on instruction accesses")
     prefetch_on_access = Param.Bool(Parent.prefetch_on_access,
         "Notify the hardware prefetcher on every access (not just misses)")
     use_virtual_addresses = Param.Bool(False,
         "Use virtual addresses for prefetching")

     _events = []
     def addEvent(self, newObject):
         self._events.append(newObject)

     # Override the normal SimObject::regProbeListeners method and
     # register deferred event handlers.
     def regProbeListeners(self):
         for event in self._events:
            event.register()
         self.getCCObject().regProbeListeners()

     def listenFromProbe(self, simObj, *probeNames):
         if not isinstance(simObj, SimObject):
             raise TypeError("argument must be of SimObject type")
         if len(probeNames) <= 0:
             raise TypeError("probeNames must have at least one element")
         self.addEvent(HWPProbeEvent(self, simObj, *probeNames))

 class QueuedPrefetcher(BasePrefetcher):
     type = "QueuedPrefetcher"
     abstract = True
     cxx_class = "QueuedPrefetcher"
     cxx_header = "mem/cache/prefetch/queued.hh"
     latency = Param.Int(1, "Latency for generated prefetches")
     queue_size = Param.Int(32, "Maximum number of queued prefetches")
     queue_squash = Param.Bool(True, "Squash queued prefetch on demand access")
     queue_filter = Param.Bool(True, "Don't queue redundant prefetches")
     cache_snoop = Param.Bool(False, "Snoop cache to eliminate redundant request")

     tag_prefetch = Param.Bool(True, "Tag prefetch with PC of generating access")

 class StridePrefetcher(QueuedPrefetcher):
     type = 'StridePrefetcher'
     cxx_class = 'StridePrefetcher'
     cxx_header = "mem/cache/prefetch/stride.hh"

     # Do not consult stride prefetcher on instruction accesses
     on_inst = False

     max_conf = Param.Int(7, "Maximum confidence level")
     thresh_conf = Param.Int(4, "Threshold confidence level")
     min_conf = Param.Int(0, "Minimum confidence level")
     start_conf = Param.Int(4, "Starting confidence for new entries")

     table_sets = Param.Int(16, "Number of sets in PC lookup table")
     table_assoc = Param.Int(4, "Associativity of PC lookup table")
     use_master_id = Param.Bool(True, "Use master id based history")

     degree = Param.Int(4, "Number of prefetches to generate")

     # Get replacement policy
     replacement_policy = Param.BaseReplacementPolicy(RandomRP(),
         "Replacement policy")

 class TaggedPrefetcher(QueuedPrefetcher):
     type = 'TaggedPrefetcher'
     cxx_class = 'TaggedPrefetcher'
     cxx_header = "mem/cache/prefetch/tagged.hh"

     degree = Param.Int(2, "Number of prefetches to generate")

 class SignaturePathPrefetcher(QueuedPrefetcher):
     type = 'SignaturePathPrefetcher'
     cxx_class = 'SignaturePathPrefetcher'
     cxx_header = "mem/cache/prefetch/signature_path.hh"

     signature_shift = Param.UInt8(3,
         "Number of bits to shift when calculating a new signature");
     signature_bits = Param.UInt16(12,
         "Size of the signature, in bits");
     signature_table_entries = Param.MemorySize("1024",
         "Number of entries of the signature table")
     signature_table_assoc = Param.Unsigned(2,
         "Associativity of the signature table")
     signature_table_indexing_policy = Param.BaseIndexingPolicy(
         SetAssociative(entry_size = 1, assoc = Parent.signature_table_assoc,
         size = Parent.signature_table_entries),
         "Indexing policy of the signature table")
     signature_table_replacement_policy = Param.BaseReplacementPolicy(LRURP(),
         "Replacement policy of the signature table")

     max_counter_value = Param.UInt8(7, "Maximum pattern counter value")
     pattern_table_entries = Param.MemorySize("4096",
         "Number of entries of the pattern table")
     pattern_table_assoc = Param.Unsigned(1,
         "Associativity of the pattern table")
     strides_per_pattern_entry = Param.Unsigned(4,
         "Number of strides stored in each pattern entry")
     pattern_table_indexing_policy = Param.BaseIndexingPolicy(
         SetAssociative(entry_size = 1, assoc = Parent.pattern_table_assoc,
         size = Parent.pattern_table_entries),
         "Indexing policy of the pattern table")
     pattern_table_replacement_policy = Param.BaseReplacementPolicy(LRURP(),
         "Replacement policy of the pattern table")

     prefetch_confidence_threshold = Param.Float(0.5,
         "Minimum confidence to issue prefetches")
     lookahead_confidence_threshold = Param.Float(0.75,
         "Minimum confidence to continue exploring lookahead entries")

 class SignaturePathPrefetcherV2(SignaturePathPrefetcher):
     type = 'SignaturePathPrefetcherV2'
     cxx_class = 'SignaturePathPrefetcherV2'
     cxx_header = "mem/cache/prefetch/signature_path_v2.hh"

     signature_table_entries = "256"
     signature_table_assoc = 1
     pattern_table_entries = "512"
     pattern_table_assoc = 1
     max_counter_value = 15
     prefetch_confidence_threshold = 0.25
     lookahead_confidence_threshold = 0.25

     global_history_register_entries = Param.MemorySize("8",
         "Number of entries of global history register")
     global_history_register_indexing_policy = Param.BaseIndexingPolicy(
         SetAssociative(entry_size = 1,
         assoc = Parent.global_history_register_entries,
         size = Parent.global_history_register_entries),
         "Indexing policy of the global history register")
     global_history_register_replacement_policy = Param.BaseReplacementPolicy(
         LRURP(), "Replacement policy of the global history register")

 class AccessMapPatternMatchingPrefetcher(QueuedPrefetcher):
     type = 'AccessMapPatternMatchingPrefetcher'
     cxx_class = 'AccessMapPatternMatchingPrefetcher'
     cxx_header = "mem/cache/prefetch/access_map_pattern_matching.hh"

     start_degree = Param.Unsigned(4,
         "Initial degree (Maximum number of prefetches generated")
     hot_zone_size = Param.MemorySize("2kB", "Memory covered by a hot zone")
     access_map_table_entries = Param.MemorySize("256",
         "Number of entries in the access map table")
     access_map_table_assoc = Param.Unsigned(8,
         "Associativity of the access map table")
     access_map_table_indexing_policy = Param.BaseIndexingPolicy(
         SetAssociative(entry_size = 1, assoc = Parent.access_map_table_assoc,
         size = Parent.access_map_table_entries),
         "Indexing policy of the access map table")
     access_map_table_replacement_policy = Param.BaseReplacementPolicy(LRURP(),
         "Replacement policy of the access map table")
     high_coverage_threshold = Param.Float(0.25,
         "A prefetch coverage factor bigger than this is considered high")
     low_coverage_threshold = Param.Float(0.125,
         "A prefetch coverage factor smaller than this is considered low")
     high_accuracy_threshold = Param.Float(0.5,
         "A prefetch accuracy factor bigger than this is considered high")
     low_accuracy_threshold = Param.Float(0.25,
         "A prefetch accuracy factor smaller than this is considered low")
     high_cache_hit_threshold = Param.Float(0.875,
         "A cache hit ratio bigger than this is considered high")
     low_cache_hit_threshold = Param.Float(0.75,
         "A cache hit ratio smaller than this is considered low")
     epoch_cycles = Param.Cycles(256000, "Cycles in an epoch period")
     offchip_memory_latency = Param.Latency("30ns",
         "Memory latency used to compute the required memory bandwidth")
	# Copyright (c) 2012, 2014 ARM Limited
	# All rights reserved.
	#
	# The license below extends only to copyright in the software and shall
	# not be construed as granting a license to any other intellectual
	# property including but not limited to intellectual property relating
	# to a hardware implementation of the functionality of the software
	# licensed hereunder. You may use the software subject to the license
	# terms below provided that you ensure that this notice is replicated
	# unmodified and in its entirety in all distributions of the software,
	# modified or unmodified, in source code or in binary form.
	#
	# Copyright (c) 2005 The Regents of The University of Michigan
	# 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: Ron Dreslinski
	# Mitch Hayenga

	from ClockedObject import ClockedObject
	from IndexingPolicies import *
	from m5.SimObject import *
	from m5.params import *
	from m5.proxy import *
	from ReplacementPolicies import *

	class HWPProbeEvent(object):
	def __init__(self, prefetcher, obj, *listOfNames):
	self.obj = obj
	self.prefetcher = prefetcher
	self.names = listOfNames

	def register(self):
	if self.obj:
	for name in self.names:
	self.prefetcher.getCCObject().addEventProbe(
	self.obj.getCCObject(), name)

	class BasePrefetcher(ClockedObject):
	type = 'BasePrefetcher'
	abstract = True
	cxx_header = "mem/cache/prefetch/base.hh"
	cxx_exports = [
	PyBindMethod("addEventProbe"),
	]
	sys = Param.System(Parent.any, "System this prefetcher belongs to")

	# Get the block size from the parent (system)
	block_size = Param.Int(Parent.cache_line_size, "Block size in bytes")

	on_miss = Param.Bool(False, "Only notify prefetcher on misses")
	on_read = Param.Bool(True, "Notify prefetcher on reads")
	on_write = Param.Bool(True, "Notify prefetcher on writes")
	on_data = Param.Bool(True, "Notify prefetcher on data accesses")
	on_inst = Param.Bool(True, "Notify prefetcher on instruction accesses")
	prefetch_on_access = Param.Bool(Parent.prefetch_on_access,
	"Notify the hardware prefetcher on every access (not just misses)")
	use_virtual_addresses = Param.Bool(False,
	"Use virtual addresses for prefetching")

	_events = []
	def addEvent(self, newObject):
	self._events.append(newObject)

	# Override the normal SimObject::regProbeListeners method and
	# register deferred event handlers.
	def regProbeListeners(self):
	for event in self._events:
	event.register()
	self.getCCObject().regProbeListeners()

	def listenFromProbe(self, simObj, *probeNames):
	if not isinstance(simObj, SimObject):
	raise TypeError("argument must be of SimObject type")
	if len(probeNames) <= 0:
	raise TypeError("probeNames must have at least one element")
	self.addEvent(HWPProbeEvent(self, simObj, *probeNames))

	class QueuedPrefetcher(BasePrefetcher):
	type = "QueuedPrefetcher"
	abstract = True
	cxx_class = "QueuedPrefetcher"
	cxx_header = "mem/cache/prefetch/queued.hh"
	latency = Param.Int(1, "Latency for generated prefetches")
	queue_size = Param.Int(32, "Maximum number of queued prefetches")
	queue_squash = Param.Bool(True, "Squash queued prefetch on demand access")
	queue_filter = Param.Bool(True, "Don't queue redundant prefetches")
	cache_snoop = Param.Bool(False, "Snoop cache to eliminate redundant request")

	tag_prefetch = Param.Bool(True, "Tag prefetch with PC of generating access")

	class StridePrefetcher(QueuedPrefetcher):
	type = 'StridePrefetcher'
	cxx_class = 'StridePrefetcher'
	cxx_header = "mem/cache/prefetch/stride.hh"

	# Do not consult stride prefetcher on instruction accesses
	on_inst = False

	max_conf = Param.Int(7, "Maximum confidence level")
	thresh_conf = Param.Int(4, "Threshold confidence level")
	min_conf = Param.Int(0, "Minimum confidence level")
	start_conf = Param.Int(4, "Starting confidence for new entries")

	table_sets = Param.Int(16, "Number of sets in PC lookup table")
	table_assoc = Param.Int(4, "Associativity of PC lookup table")
	use_master_id = Param.Bool(True, "Use master id based history")

	degree = Param.Int(4, "Number of prefetches to generate")

	# Get replacement policy
	replacement_policy = Param.BaseReplacementPolicy(RandomRP(),
	"Replacement policy")

	class TaggedPrefetcher(QueuedPrefetcher):
	type = 'TaggedPrefetcher'
	cxx_class = 'TaggedPrefetcher'
	cxx_header = "mem/cache/prefetch/tagged.hh"

	degree = Param.Int(2, "Number of prefetches to generate")

	class SignaturePathPrefetcher(QueuedPrefetcher):
	type = 'SignaturePathPrefetcher'
	cxx_class = 'SignaturePathPrefetcher'
	cxx_header = "mem/cache/prefetch/signature_path.hh"

	signature_shift = Param.UInt8(3,
	"Number of bits to shift when calculating a new signature");
	signature_bits = Param.UInt16(12,
	"Size of the signature, in bits");
	signature_table_entries = Param.MemorySize("1024",
	"Number of entries of the signature table")
	signature_table_assoc = Param.Unsigned(2,
	"Associativity of the signature table")
	signature_table_indexing_policy = Param.BaseIndexingPolicy(
	SetAssociative(entry_size = 1, assoc = Parent.signature_table_assoc,
	size = Parent.signature_table_entries),
	"Indexing policy of the signature table")
	signature_table_replacement_policy = Param.BaseReplacementPolicy(LRURP(),
	"Replacement policy of the signature table")

	max_counter_value = Param.UInt8(7, "Maximum pattern counter value")
	pattern_table_entries = Param.MemorySize("4096",
	"Number of entries of the pattern table")
	pattern_table_assoc = Param.Unsigned(1,
	"Associativity of the pattern table")
	strides_per_pattern_entry = Param.Unsigned(4,
	"Number of strides stored in each pattern entry")
	pattern_table_indexing_policy = Param.BaseIndexingPolicy(
	SetAssociative(entry_size = 1, assoc = Parent.pattern_table_assoc,
	size = Parent.pattern_table_entries),
	"Indexing policy of the pattern table")
	pattern_table_replacement_policy = Param.BaseReplacementPolicy(LRURP(),
	"Replacement policy of the pattern table")

	prefetch_confidence_threshold = Param.Float(0.5,
	"Minimum confidence to issue prefetches")
	lookahead_confidence_threshold = Param.Float(0.75,
	"Minimum confidence to continue exploring lookahead entries")

	class SignaturePathPrefetcherV2(SignaturePathPrefetcher):
	type = 'SignaturePathPrefetcherV2'
	cxx_class = 'SignaturePathPrefetcherV2'
	cxx_header = "mem/cache/prefetch/signature_path_v2.hh"

	signature_table_entries = "256"
	signature_table_assoc = 1
	pattern_table_entries = "512"
	pattern_table_assoc = 1
	max_counter_value = 15
	prefetch_confidence_threshold = 0.25
	lookahead_confidence_threshold = 0.25

	global_history_register_entries = Param.MemorySize("8",
	"Number of entries of global history register")
	global_history_register_indexing_policy = Param.BaseIndexingPolicy(
	SetAssociative(entry_size = 1,
	assoc = Parent.global_history_register_entries,
	size = Parent.global_history_register_entries),
	"Indexing policy of the global history register")
	global_history_register_replacement_policy = Param.BaseReplacementPolicy(
	LRURP(), "Replacement policy of the global history register")

	class AccessMapPatternMatchingPrefetcher(QueuedPrefetcher):
	type = 'AccessMapPatternMatchingPrefetcher'
	cxx_class = 'AccessMapPatternMatchingPrefetcher'
	cxx_header = "mem/cache/prefetch/access_map_pattern_matching.hh"

	start_degree = Param.Unsigned(4,
	"Initial degree (Maximum number of prefetches generated")
	hot_zone_size = Param.MemorySize("2kB", "Memory covered by a hot zone")
	access_map_table_entries = Param.MemorySize("256",
	"Number of entries in the access map table")
	access_map_table_assoc = Param.Unsigned(8,
	"Associativity of the access map table")
	access_map_table_indexing_policy = Param.BaseIndexingPolicy(
	SetAssociative(entry_size = 1, assoc = Parent.access_map_table_assoc,
	size = Parent.access_map_table_entries),
	"Indexing policy of the access map table")
	access_map_table_replacement_policy = Param.BaseReplacementPolicy(LRURP(),
	"Replacement policy of the access map table")
	high_coverage_threshold = Param.Float(0.25,
	"A prefetch coverage factor bigger than this is considered high")
	low_coverage_threshold = Param.Float(0.125,
	"A prefetch coverage factor smaller than this is considered low")
	high_accuracy_threshold = Param.Float(0.5,
	"A prefetch accuracy factor bigger than this is considered high")
	low_accuracy_threshold = Param.Float(0.25,
	"A prefetch accuracy factor smaller than this is considered low")
	high_cache_hit_threshold = Param.Float(0.875,
	"A cache hit ratio bigger than this is considered high")
	low_cache_hit_threshold = Param.Float(0.75,
	"A cache hit ratio smaller than this is considered low")
	epoch_cycles = Param.Cycles(256000, "Cycles in an epoch period")
	offchip_memory_latency = Param.Latency("30ns",
	"Memory latency used to compute the required memory bandwidth")