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mem-ruby: Minor Ruby Prefetcher fixes

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Minor fixes to the Ruby stride prefetcher. This includes removing unused
statistics and changing where/when some statistics are updated.

Change-Id: If758bf009f53fad277cb3cd754d57a0b10737599
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/24363
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>
Tested-by: kokoro <noreply+kokoro@google.com>
This commit is contained in:
Timothy Hayes
2019-10-21 15:17:13 +01:00
committed by Giacomo Travaglini
parent de24aafc16
commit 2e5d0198d6
3 changed files with 42 additions and 20 deletions
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31
src/mem/ruby/structures/Prefetcher.cc
View File

@@ -1,4 +1,16 @@
/*
* Copyright (c) 2020 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) 1999-2012 Mark D. Hill and David A. Wood
* All rights reserved.
*
@@ -105,19 +117,9 @@ Prefetcher::regStats()
.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")
.desc("number of prefetched blocks accessed (for the first time)")
;
numPartialHits
@@ -157,7 +159,7 @@ Prefetcher::observeMiss(Addr address, const RubyRequestType& type)
// The controller has issued the prefetch request,
// but the request for the block arrived earlier.
numPartialHits++;
observePfHit(line_addr);
observePfMiss(line_addr);
return;
}
} else {
@@ -242,16 +244,17 @@ Prefetcher::issueNextPrefetch(Addr address, PrefetchEntry *stream)
// possibly stop prefetching at page boundaries
if (page_addr != pageAddress(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;
}
numPagesCrossed++;
}
// launch next prefetch
numPrefetchRequested++;
stream->m_address = line_addr;
stream->m_use_time = m_controller->curCycle();
DPRINTF(RubyPrefetcher, "Requesting prefetch for %#x\n", line_addr);
@@ -308,12 +311,12 @@ Prefetcher::initializeStream(Addr address, int stride,
line_addr = makeNextStrideAddress(line_addr, stride);
// possibly stop prefetching at page boundaries
if (page_addr != pageAddress(line_addr)) {
numPagesCrossed++;
if (!m_prefetch_cross_pages) {
// deallocate this stream prefetcher
mystream->m_is_valid = false;
return;
}
numPagesCrossed++;
}
// launch prefetch

18
src/mem/ruby/structures/Prefetcher.hh
View File

@@ -1,4 +1,16 @@
/*
* Copyright (c) 2020 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) 1999-2012 Mark D. Hill and David A. Wood
* All rights reserved.
*
@@ -166,7 +178,7 @@ class Prefetcher : public SimObject
//! have been hit
uint32_t *m_unit_filter_hit;
//! a negative nit stride filter array: helps reduce BW requirement
//! a negative unit stride filter array: helps reduce BW requirement
//! of prefetching
std::vector<Addr> m_negative_filter;
/// a round robin pointer into the negative filter group
@@ -199,10 +211,6 @@ class Prefetcher : public SimObject
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

13
src/mem/ruby/structures/RubyPrefetcher.py
View File

@@ -1,3 +1,15 @@
# Copyright (c) 2020 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) 2012 Mark D. Hill and David A. Wood
# All rights reserved.
#
@@ -37,7 +49,6 @@ class Prefetcher(SimObject):
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,