Prefetcher.py revision 13700:56fa28e6fab4
15425Sgblack@eecs.umich.edu# Copyright (c) 2012, 2014 ARM Limited
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35425Sgblack@eecs.umich.edu#
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395425Sgblack@eecs.umich.edu# Authors: Ron Dreslinski
405425Sgblack@eecs.umich.edu#          Mitch Hayenga
415425Sgblack@eecs.umich.edu
425425Sgblack@eecs.umich.edufrom m5.SimObject import *
435425Sgblack@eecs.umich.edufrom m5.params import *
445425Sgblack@eecs.umich.edufrom m5.proxy import *
4514277Sgabeblack@google.com
465425Sgblack@eecs.umich.edufrom m5.objects.ClockedObject import ClockedObject
475425Sgblack@eecs.umich.edufrom m5.objects.IndexingPolicies import *
4814277Sgabeblack@google.comfrom m5.objects.ReplacementPolicies import *
495425Sgblack@eecs.umich.edu
505425Sgblack@eecs.umich.educlass HWPProbeEvent(object):
5114277Sgabeblack@google.com    def __init__(self, prefetcher, obj, *listOfNames):
5214277Sgabeblack@google.com        self.obj = obj
5314277Sgabeblack@google.com        self.prefetcher = prefetcher
5414277Sgabeblack@google.com        self.names = listOfNames
5514277Sgabeblack@google.com
5614277Sgabeblack@google.com    def register(self):
5714277Sgabeblack@google.com        if self.obj:
5814277Sgabeblack@google.com            for name in self.names:
5914277Sgabeblack@google.com                self.prefetcher.getCCObject().addEventProbe(
605425Sgblack@eecs.umich.edu                    self.obj.getCCObject(), name)
617965Sgblack@eecs.umich.edu
627965Sgblack@eecs.umich.educlass BasePrefetcher(ClockedObject):
637965Sgblack@eecs.umich.edu    type = 'BasePrefetcher'
647965Sgblack@eecs.umich.edu    abstract = True
657965Sgblack@eecs.umich.edu    cxx_header = "mem/cache/prefetch/base.hh"
667965Sgblack@eecs.umich.edu    cxx_exports = [
6714277Sgabeblack@google.com        PyBindMethod("addEventProbe"),
687965Sgblack@eecs.umich.edu    ]
697965Sgblack@eecs.umich.edu    sys = Param.System(Parent.any, "System this prefetcher belongs to")
707965Sgblack@eecs.umich.edu
715425Sgblack@eecs.umich.edu    # Get the block size from the parent (system)
725425Sgblack@eecs.umich.edu    block_size = Param.Int(Parent.cache_line_size, "Block size in bytes")
7314277Sgabeblack@google.com
745425Sgblack@eecs.umich.edu    on_miss = Param.Bool(False, "Only notify prefetcher on misses")
7514277Sgabeblack@google.com    on_read = Param.Bool(True, "Notify prefetcher on reads")
7614277Sgabeblack@google.com    on_write = Param.Bool(True, "Notify prefetcher on writes")
7714277Sgabeblack@google.com    on_data  = Param.Bool(True, "Notify prefetcher on data accesses")
785425Sgblack@eecs.umich.edu    on_inst  = Param.Bool(True, "Notify prefetcher on instruction accesses")
7914277Sgabeblack@google.com    prefetch_on_access = Param.Bool(Parent.prefetch_on_access,
8014277Sgabeblack@google.com        "Notify the hardware prefetcher on every access (not just misses)")
8114277Sgabeblack@google.com    use_virtual_addresses = Param.Bool(False,
825425Sgblack@eecs.umich.edu        "Use virtual addresses for prefetching")
8312236Sgabeblack@google.com
845425Sgblack@eecs.umich.edu    _events = []
855425Sgblack@eecs.umich.edu    def addEvent(self, newObject):
865425Sgblack@eecs.umich.edu        self._events.append(newObject)
8714277Sgabeblack@google.com
8814277Sgabeblack@google.com    # Override the normal SimObject::regProbeListeners method and
8914277Sgabeblack@google.com    # register deferred event handlers.
9014277Sgabeblack@google.com    def regProbeListeners(self):
9114277Sgabeblack@google.com        for event in self._events:
9214277Sgabeblack@google.com           event.register()
9314277Sgabeblack@google.com        self.getCCObject().regProbeListeners()
9414277Sgabeblack@google.com
9514277Sgabeblack@google.com    def listenFromProbe(self, simObj, *probeNames):
9614277Sgabeblack@google.com        if not isinstance(simObj, SimObject):
9714277Sgabeblack@google.com            raise TypeError("argument must be of SimObject type")
987965Sgblack@eecs.umich.edu        if len(probeNames) <= 0:
9912234Sgabeblack@google.com            raise TypeError("probeNames must have at least one element")
1005425Sgblack@eecs.umich.edu        self.addEvent(HWPProbeEvent(self, simObj, *probeNames))
1015425Sgblack@eecs.umich.edu
1025425Sgblack@eecs.umich.educlass QueuedPrefetcher(BasePrefetcher):
1035425Sgblack@eecs.umich.edu    type = "QueuedPrefetcher"
1045425Sgblack@eecs.umich.edu    abstract = True
10514277Sgabeblack@google.com    cxx_class = "QueuedPrefetcher"
1067965Sgblack@eecs.umich.edu    cxx_header = "mem/cache/prefetch/queued.hh"
1077965Sgblack@eecs.umich.edu    latency = Param.Int(1, "Latency for generated prefetches")
1085425Sgblack@eecs.umich.edu    queue_size = Param.Int(32, "Maximum number of queued prefetches")
1095425Sgblack@eecs.umich.edu    queue_squash = Param.Bool(True, "Squash queued prefetch on demand access")
1105425Sgblack@eecs.umich.edu    queue_filter = Param.Bool(True, "Don't queue redundant prefetches")
1115425Sgblack@eecs.umich.edu    cache_snoop = Param.Bool(False, "Snoop cache to eliminate redundant request")
11214277Sgabeblack@google.com
1137975Sgblack@eecs.umich.edu    tag_prefetch = Param.Bool(True, "Tag prefetch with PC of generating access")
11414277Sgabeblack@google.com
11514277Sgabeblack@google.comclass StridePrefetcher(QueuedPrefetcher):
11614277Sgabeblack@google.com    type = 'StridePrefetcher'
11714277Sgabeblack@google.com    cxx_class = 'StridePrefetcher'
11814277Sgabeblack@google.com    cxx_header = "mem/cache/prefetch/stride.hh"
1195425Sgblack@eecs.umich.edu
1207626Sgblack@eecs.umich.edu    # Do not consult stride prefetcher on instruction accesses
1215425Sgblack@eecs.umich.edu    on_inst = False
1225425Sgblack@eecs.umich.edu
1235425Sgblack@eecs.umich.edu    max_conf = Param.Int(7, "Maximum confidence level")
1245425Sgblack@eecs.umich.edu    thresh_conf = Param.Int(4, "Threshold confidence level")
12514277Sgabeblack@google.com    min_conf = Param.Int(0, "Minimum confidence level")
12614277Sgabeblack@google.com    start_conf = Param.Int(4, "Starting confidence for new entries")
12714277Sgabeblack@google.com
12814277Sgabeblack@google.com    table_sets = Param.Int(16, "Number of sets in PC lookup table")
12914277Sgabeblack@google.com    table_assoc = Param.Int(4, "Associativity of PC lookup table")
13014277Sgabeblack@google.com    use_master_id = Param.Bool(True, "Use master id based history")
13114277Sgabeblack@google.com
13214277Sgabeblack@google.com    degree = Param.Int(4, "Number of prefetches to generate")
13314277Sgabeblack@google.com
1345425Sgblack@eecs.umich.edu    # Get replacement policy
13514277Sgabeblack@google.com    replacement_policy = Param.BaseReplacementPolicy(RandomRP(),
13614277Sgabeblack@google.com        "Replacement policy")
13714277Sgabeblack@google.com
1385425Sgblack@eecs.umich.educlass TaggedPrefetcher(QueuedPrefetcher):
13914277Sgabeblack@google.com    type = 'TaggedPrefetcher'
14014277Sgabeblack@google.com    cxx_class = 'TaggedPrefetcher'
14114277Sgabeblack@google.com    cxx_header = "mem/cache/prefetch/tagged.hh"
14214277Sgabeblack@google.com
14314277Sgabeblack@google.com    degree = Param.Int(2, "Number of prefetches to generate")
14414277Sgabeblack@google.com
1455425Sgblack@eecs.umich.educlass SignaturePathPrefetcher(QueuedPrefetcher):
1467620Sgblack@eecs.umich.edu    type = 'SignaturePathPrefetcher'
14714277Sgabeblack@google.com    cxx_class = 'SignaturePathPrefetcher'
14814277Sgabeblack@google.com    cxx_header = "mem/cache/prefetch/signature_path.hh"
14914277Sgabeblack@google.com
15014277Sgabeblack@google.com    signature_shift = Param.UInt8(3,
15114277Sgabeblack@google.com        "Number of bits to shift when calculating a new signature");
15214277Sgabeblack@google.com    signature_bits = Param.UInt16(12,
15314277Sgabeblack@google.com        "Size of the signature, in bits");
15414277Sgabeblack@google.com    signature_table_entries = Param.MemorySize("1024",
15514277Sgabeblack@google.com        "Number of entries of the signature table")
15614277Sgabeblack@google.com    signature_table_assoc = Param.Unsigned(2,
15714277Sgabeblack@google.com        "Associativity of the signature table")
1585425Sgblack@eecs.umich.edu    signature_table_indexing_policy = Param.BaseIndexingPolicy(
15914277Sgabeblack@google.com        SetAssociative(entry_size = 1, assoc = Parent.signature_table_assoc,
16014277Sgabeblack@google.com        size = Parent.signature_table_entries),
1615425Sgblack@eecs.umich.edu        "Indexing policy of the signature table")
16214277Sgabeblack@google.com    signature_table_replacement_policy = Param.BaseReplacementPolicy(LRURP(),
16314277Sgabeblack@google.com        "Replacement policy of the signature table")
1645425Sgblack@eecs.umich.edu
16514277Sgabeblack@google.com    max_counter_value = Param.UInt8(7, "Maximum pattern counter value")
1665425Sgblack@eecs.umich.edu    pattern_table_entries = Param.MemorySize("4096",
16714277Sgabeblack@google.com        "Number of entries of the pattern table")
16814277Sgabeblack@google.com    pattern_table_assoc = Param.Unsigned(1,
16914277Sgabeblack@google.com        "Associativity of the pattern table")
17014277Sgabeblack@google.com    strides_per_pattern_entry = Param.Unsigned(4,
1715425Sgblack@eecs.umich.edu        "Number of strides stored in each pattern entry")
1725425Sgblack@eecs.umich.edu    pattern_table_indexing_policy = Param.BaseIndexingPolicy(
17314277Sgabeblack@google.com        SetAssociative(entry_size = 1, assoc = Parent.pattern_table_assoc,
17414277Sgabeblack@google.com        size = Parent.pattern_table_entries),
17514277Sgabeblack@google.com        "Indexing policy of the pattern table")
1765425Sgblack@eecs.umich.edu    pattern_table_replacement_policy = Param.BaseReplacementPolicy(LRURP(),
17714277Sgabeblack@google.com        "Replacement policy of the pattern table")
1785425Sgblack@eecs.umich.edu
17914277Sgabeblack@google.com    prefetch_confidence_threshold = Param.Float(0.5,
18014277Sgabeblack@google.com        "Minimum confidence to issue prefetches")
18114277Sgabeblack@google.com    lookahead_confidence_threshold = Param.Float(0.75,
18214277Sgabeblack@google.com        "Minimum confidence to continue exploring lookahead entries")
18314277Sgabeblack@google.com
18414277Sgabeblack@google.comclass SignaturePathPrefetcherV2(SignaturePathPrefetcher):
18514277Sgabeblack@google.com    type = 'SignaturePathPrefetcherV2'
18614277Sgabeblack@google.com    cxx_class = 'SignaturePathPrefetcherV2'
18714277Sgabeblack@google.com    cxx_header = "mem/cache/prefetch/signature_path_v2.hh"
18814277Sgabeblack@google.com
18914277Sgabeblack@google.com    signature_table_entries = "256"
19014277Sgabeblack@google.com    signature_table_assoc = 1
19114277Sgabeblack@google.com    pattern_table_entries = "512"
19214277Sgabeblack@google.com    pattern_table_assoc = 1
19314277Sgabeblack@google.com    max_counter_value = 15
19414277Sgabeblack@google.com    prefetch_confidence_threshold = 0.25
19514277Sgabeblack@google.com    lookahead_confidence_threshold = 0.25
1965425Sgblack@eecs.umich.edu
197    global_history_register_entries = Param.MemorySize("8",
198        "Number of entries of global history register")
199    global_history_register_indexing_policy = Param.BaseIndexingPolicy(
200        SetAssociative(entry_size = 1,
201        assoc = Parent.global_history_register_entries,
202        size = Parent.global_history_register_entries),
203        "Indexing policy of the global history register")
204    global_history_register_replacement_policy = Param.BaseReplacementPolicy(
205        LRURP(), "Replacement policy of the global history register")
206
207class AccessMapPatternMatching(ClockedObject):
208    type = 'AccessMapPatternMatching'
209    cxx_class = 'AccessMapPatternMatching'
210    cxx_header = "mem/cache/prefetch/access_map_pattern_matching.hh"
211
212    block_size = Param.Unsigned(Parent.block_size,
213        "Cacheline size used by the prefetcher using this object")
214
215    limit_stride = Param.Unsigned(0,
216        "Limit the strides checked up to -X/X, if 0, disable the limit")
217    start_degree = Param.Unsigned(4,
218        "Initial degree (Maximum number of prefetches generated")
219    hot_zone_size = Param.MemorySize("2kB", "Memory covered by a hot zone")
220    access_map_table_entries = Param.MemorySize("256",
221        "Number of entries in the access map table")
222    access_map_table_assoc = Param.Unsigned(8,
223        "Associativity of the access map table")
224    access_map_table_indexing_policy = Param.BaseIndexingPolicy(
225        SetAssociative(entry_size = 1, assoc = Parent.access_map_table_assoc,
226        size = Parent.access_map_table_entries),
227        "Indexing policy of the access map table")
228    access_map_table_replacement_policy = Param.BaseReplacementPolicy(LRURP(),
229        "Replacement policy of the access map table")
230    high_coverage_threshold = Param.Float(0.25,
231        "A prefetch coverage factor bigger than this is considered high")
232    low_coverage_threshold = Param.Float(0.125,
233        "A prefetch coverage factor smaller than this is considered low")
234    high_accuracy_threshold = Param.Float(0.5,
235        "A prefetch accuracy factor bigger than this is considered high")
236    low_accuracy_threshold = Param.Float(0.25,
237        "A prefetch accuracy factor smaller than this is considered low")
238    high_cache_hit_threshold = Param.Float(0.875,
239        "A cache hit ratio bigger than this is considered high")
240    low_cache_hit_threshold = Param.Float(0.75,
241        "A cache hit ratio smaller than this is considered low")
242    epoch_cycles = Param.Cycles(256000, "Cycles in an epoch period")
243    offchip_memory_latency = Param.Latency("30ns",
244        "Memory latency used to compute the required memory bandwidth")
245
246class AMPMPrefetcher(QueuedPrefetcher):
247    type = 'AMPMPrefetcher'
248    cxx_class = 'AMPMPrefetcher'
249    cxx_header = "mem/cache/prefetch/access_map_pattern_matching.hh"
250    ampm = Param.AccessMapPatternMatching( AccessMapPatternMatching(),
251        "Access Map Pattern Matching object")
252
253class DeltaCorrelatingPredictionTables(SimObject):
254    type = 'DeltaCorrelatingPredictionTables'
255    cxx_class = 'DeltaCorrelatingPredictionTables'
256    cxx_header = "mem/cache/prefetch/delta_correlating_prediction_tables.hh"
257    deltas_per_entry = Param.Unsigned(20,
258        "Number of deltas stored in each table entry")
259    delta_bits = Param.Unsigned(12, "Bits per delta")
260    delta_mask_bits = Param.Unsigned(8,
261        "Lower bits to mask when comparing deltas")
262    table_entries = Param.MemorySize("128",
263        "Number of entries in the table")
264    table_assoc = Param.Unsigned(128,
265        "Associativity of the table")
266    table_indexing_policy = Param.BaseIndexingPolicy(
267        SetAssociative(entry_size = 1, assoc = Parent.table_assoc,
268        size = Parent.table_entries),
269        "Indexing policy of the table")
270    table_replacement_policy = Param.BaseReplacementPolicy(LRURP(),
271        "Replacement policy of the table")
272
273class DCPTPrefetcher(QueuedPrefetcher):
274    type = 'DCPTPrefetcher'
275    cxx_class = 'DCPTPrefetcher'
276    cxx_header = "mem/cache/prefetch/delta_correlating_prediction_tables.hh"
277    dcpt = Param.DeltaCorrelatingPredictionTables(
278        DeltaCorrelatingPredictionTables(),
279        "Delta Correlating Prediction Tables object")
280
281class IrregularStreamBufferPrefetcher(QueuedPrefetcher):
282    type = "IrregularStreamBufferPrefetcher"
283    cxx_class = "IrregularStreamBufferPrefetcher"
284    cxx_header = "mem/cache/prefetch/irregular_stream_buffer.hh"
285
286    max_counter_value = Param.Unsigned(3,
287        "Maximum value of the confidence counter")
288    chunk_size = Param.Unsigned(256,
289        "Maximum number of addresses in a temporal stream")
290    degree = Param.Unsigned(4, "Number of prefetches to generate")
291    training_unit_assoc = Param.Unsigned(128,
292        "Associativity of the training unit")
293    training_unit_entries = Param.MemorySize("128",
294        "Number of entries of the training unit")
295    training_unit_indexing_policy = Param.BaseIndexingPolicy(
296        SetAssociative(entry_size = 1, assoc = Parent.training_unit_assoc,
297        size = Parent.training_unit_entries),
298        "Indexing policy of the training unit")
299    training_unit_replacement_policy = Param.BaseReplacementPolicy(LRURP(),
300        "Replacement policy of the training unit")
301
302    prefetch_candidates_per_entry = Param.Unsigned(16,
303        "Number of prefetch candidates stored in a SP-AMC entry")
304    address_map_cache_assoc = Param.Unsigned(128,
305        "Associativity of the PS/SP AMCs")
306    address_map_cache_entries = Param.MemorySize("128",
307        "Number of entries of the PS/SP AMCs")
308    ps_address_map_cache_indexing_policy = Param.BaseIndexingPolicy(
309        SetAssociative(entry_size = 1,
310        assoc = Parent.address_map_cache_assoc,
311        size = Parent.address_map_cache_entries),
312        "Indexing policy of the Physical-to-Structural Address Map Cache")
313    ps_address_map_cache_replacement_policy = Param.BaseReplacementPolicy(
314        LRURP(),
315        "Replacement policy of the Physical-to-Structural Address Map Cache")
316    sp_address_map_cache_indexing_policy = Param.BaseIndexingPolicy(
317        SetAssociative(entry_size = 1,
318        assoc = Parent.address_map_cache_assoc,
319        size = Parent.address_map_cache_entries),
320        "Indexing policy of the Structural-to-Physical Address Mao Cache")
321    sp_address_map_cache_replacement_policy = Param.BaseReplacementPolicy(
322        LRURP(),
323        "Replacement policy of the Structural-to-Physical Address Map Cache")
324
325class SlimAccessMapPatternMatching(AccessMapPatternMatching):
326    start_degree = 2
327    limit_stride = 4
328
329class SlimDeltaCorrelatingPredictionTables(DeltaCorrelatingPredictionTables):
330    table_entries = "256"
331    table_assoc = 256
332    deltas_per_entry = 9
333
334class SlimAMPMPrefetcher(QueuedPrefetcher):
335    type = 'SlimAMPMPrefetcher'
336    cxx_class = 'SlimAMPMPrefetcher'
337    cxx_header = "mem/cache/prefetch/slim_ampm.hh"
338
339    ampm = Param.AccessMapPatternMatching(SlimAccessMapPatternMatching(),
340        "Access Map Pattern Matching object")
341    dcpt = Param.DeltaCorrelatingPredictionTables(
342        SlimDeltaCorrelatingPredictionTables(),
343        "Delta Correlating Prediction Tables object")
344