From b4c472945a6313e1ae1f4ba01477360c372dea6b Mon Sep 17 00:00:00 2001 From: Andreas Sandberg Date: Tue, 12 Apr 2016 09:10:13 -0500 Subject: [PATCH] mem-cache: Add multi-prefetcher adaptor This patch adds a meta-prefetcher that enables gem5's cache models to connect to multiple prefetchers. Sub-prefetchers still use the probes-based interface and training can be controlled independently. However, when the cache requests a prefetch packet, the adaptor traverses the priority list of prefetchers and uses the first prefetcher that is able to generate a prefetch. Kudos to Mitch Hayenga for the original version of this patch. Change-Id: I25569a834997e5404c7183ec995d212912c5dcdf Signed-off-by: Andreas Sandberg Reviewed-by: Nikos Nikoleris Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/18868 Reviewed-by: Daniel Carvalho Maintainer: Nikos Nikoleris Tested-by: kokoro --- src/mem/cache/prefetch/Prefetcher.py | 9 ++- src/mem/cache/prefetch/SConscript | 1 + src/mem/cache/prefetch/base.hh | 2 +- src/mem/cache/prefetch/multi.cc | 88 ++++++++++++++++++++++++++++ src/mem/cache/prefetch/multi.hh | 72 +++++++++++++++++++++++ 5 files changed, 170 insertions(+), 2 deletions(-) create mode 100644 src/mem/cache/prefetch/multi.cc create mode 100644 src/mem/cache/prefetch/multi.hh diff --git a/src/mem/cache/prefetch/Prefetcher.py b/src/mem/cache/prefetch/Prefetcher.py index b933b4953..3810b6afd 100644 --- a/src/mem/cache/prefetch/Prefetcher.py +++ b/src/mem/cache/prefetch/Prefetcher.py @@ -1,4 +1,4 @@ -# Copyright (c) 2012, 2014 ARM Limited +# Copyright (c) 2012, 2014, 2019 ARM Limited # All rights reserved. # # The license below extends only to copyright in the software and shall @@ -99,6 +99,13 @@ class BasePrefetcher(ClockedObject): raise TypeError("probeNames must have at least one element") self.addEvent(HWPProbeEvent(self, simObj, *probeNames)) +class MultiPrefetcher(BasePrefetcher): + type = 'MultiPrefetcher' + cxx_class = 'MultiPrefetcher' + cxx_header = 'mem/cache/prefetch/multi.hh' + + prefetchers = VectorParam.BasePrefetcher([], "Array of prefetchers") + class QueuedPrefetcher(BasePrefetcher): type = "QueuedPrefetcher" abstract = True diff --git a/src/mem/cache/prefetch/SConscript b/src/mem/cache/prefetch/SConscript index 0dae74e27..312dc2d1a 100644 --- a/src/mem/cache/prefetch/SConscript +++ b/src/mem/cache/prefetch/SConscript @@ -34,6 +34,7 @@ SimObject('Prefetcher.py') Source('access_map_pattern_matching.cc') Source('base.cc') +Source('multi.cc') Source('bop.cc') Source('delta_correlating_prediction_tables.cc') Source('irregular_stream_buffer.cc') diff --git a/src/mem/cache/prefetch/base.hh b/src/mem/cache/prefetch/base.hh index 3ef607fad..f4a61b21a 100644 --- a/src/mem/cache/prefetch/base.hh +++ b/src/mem/cache/prefetch/base.hh @@ -332,7 +332,7 @@ class BasePrefetcher : public ClockedObject virtual ~BasePrefetcher() {} - void setCache(BaseCache *_cache); + virtual void setCache(BaseCache *_cache); /** * Notify prefetcher of cache access (may be any access or just diff --git a/src/mem/cache/prefetch/multi.cc b/src/mem/cache/prefetch/multi.cc new file mode 100644 index 000000000..02cb6cfca --- /dev/null +++ b/src/mem/cache/prefetch/multi.cc @@ -0,0 +1,88 @@ +/* + * Copyright (c) 2014, 2019 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. + * + * 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: Mitch Hayenga + * Andreas Sandberg + */ + +#include "mem/cache/prefetch/multi.hh" + +#include "params/MultiPrefetcher.hh" + +MultiPrefetcher::MultiPrefetcher(const MultiPrefetcherParams *p) + : BasePrefetcher(p), + prefetchers(p->prefetchers.begin(), p->prefetchers.end()) +{ +} + +void +MultiPrefetcher::setCache(BaseCache *_cache) +{ + for (auto pf : prefetchers) + pf->setCache(_cache); +} + +Tick +MultiPrefetcher::nextPrefetchReadyTime() const +{ + Tick next_ready = MaxTick; + + for (auto pf : prefetchers) + next_ready = std::min(next_ready, pf->nextPrefetchReadyTime()); + + return next_ready; +} + +PacketPtr +MultiPrefetcher::getPacket() +{ + for (auto pf : prefetchers) { + if (pf->nextPrefetchReadyTime() <= curTick()) { + PacketPtr pkt = pf->getPacket(); + panic_if(!pkt, "Prefetcher is ready but didn't return a packet."); + return pkt; + } + } + + return nullptr; +} + + +MultiPrefetcher* +MultiPrefetcherParams::create() +{ + return new MultiPrefetcher(this); +} diff --git a/src/mem/cache/prefetch/multi.hh b/src/mem/cache/prefetch/multi.hh new file mode 100644 index 000000000..88760f585 --- /dev/null +++ b/src/mem/cache/prefetch/multi.hh @@ -0,0 +1,72 @@ +/* + * Copyright (c) 2014, 2019 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. + * + * 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: Mitch Hayenga + * Andreas Sandberg + */ + +#ifndef __MEM_CACHE_PREFETCH_MULTI_HH__ +#define __MEM_CACHE_PREFETCH_MULTI_HH__ + +#include "mem/cache/prefetch/base.hh" + +struct MultiPrefetcherParams; + +class MultiPrefetcher : public BasePrefetcher +{ + public: // SimObject + MultiPrefetcher(const MultiPrefetcherParams *p); + + public: // BasePrefetcher + void setCache(BaseCache *_cache) override; + PacketPtr getPacket() override; + Tick nextPrefetchReadyTime() const override; + + /** @{ */ + /** + * Ignore notifications since each sub-prefetcher already gets a + * notification through their probes-based interface. + */ + void notify(const PacketPtr &pkt, const PrefetchInfo &pfi) override {}; + void notifyFill(const PacketPtr &pkt) override {}; + /** @} */ + + protected: + /** List of sub-prefetchers ordered by priority. */ + std::list prefetchers; +}; + +#endif //__MEM_CACHE_PREFETCH_MULTI_HH__ -- 2.30.2