Nathanael Premillieu has submitted this change. (
https://gem5-review.googlesource.com/c/public/gem5/+/47204 )
Change subject: mem-cache: adding late prefetch stats
......................................................................
mem-cache: adding late prefetch stats
Adding a late prefetch stat plus stats for each reason a prefetch can be
detected as late
Change-Id: Ia6d5294e8ce58b2b0aae2be98fd0cee83be73b8d
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/47204
Reviewed-by: Daniel Carvalho <oda...@yahoo.com.br>
Reviewed-by: Nikos Nikoleris <nikos.nikole...@arm.com>
Maintainer: Daniel Carvalho <oda...@yahoo.com.br>
Tested-by: kokoro <noreply+kok...@google.com>
---
M src/mem/cache/base.cc
M src/mem/cache/prefetch/base.cc
M src/mem/cache/prefetch/base.hh
3 files changed, 63 insertions(+), 7 deletions(-)
Approvals:
Nikos Nikoleris: Looks good to me, approved
Daniel Carvalho: Looks good to me, approved; Looks good to me, approved
kokoro: Regressions pass
diff --git a/src/mem/cache/base.cc b/src/mem/cache/base.cc
index 46eb3bf..5f7d81b 100644
--- a/src/mem/cache/base.cc
+++ b/src/mem/cache/base.cc
@@ -52,6 +52,7 @@
#include "debug/CachePort.hh"
#include "debug/CacheRepl.hh"
#include "debug/CacheVerbose.hh"
+#include "debug/HWPrefetch.hh"
#include "mem/cache/compressors/base.hh"
#include "mem/cache/mshr.hh"
#include "mem/cache/prefetch/base.hh"
@@ -825,9 +826,25 @@
PacketPtr pkt = prefetcher->getPacket();
if (pkt) {
Addr pf_addr = pkt->getBlockAddr(blkSize);
- if (!tags->findBlock(pf_addr, pkt->isSecure()) &&
- !mshrQueue.findMatch(pf_addr, pkt->isSecure()) &&
- !writeBuffer.findMatch(pf_addr, pkt->isSecure())) {
+ if (tags->findBlock(pf_addr, pkt->isSecure())) {
+ DPRINTF(HWPrefetch, "Prefetch %#x has hit in cache, "
+ "dropped.\n", pf_addr);
+ prefetcher->pfHitInCache();
+ // free the request and packet
+ delete pkt;
+ } else if (mshrQueue.findMatch(pf_addr, pkt->isSecure())) {
+ DPRINTF(HWPrefetch, "Prefetch %#x has hit in a MSHR, "
+ "dropped.\n", pf_addr);
+ prefetcher->pfHitInMSHR();
+ // free the request and packet
+ delete pkt;
+ } else if (writeBuffer.findMatch(pf_addr, pkt->isSecure())) {
+ DPRINTF(HWPrefetch, "Prefetch %#x has hit in the "
+ "Write Buffer, dropped.\n", pf_addr);
+ prefetcher->pfHitInWB();
+ // free the request and packet
+ delete pkt;
+ } else {
// Update statistic on number of prefetches issued
// (hwpf_mshr_misses)
assert(pkt->req->requestorId() < system->maxRequestors());
@@ -837,9 +854,6 @@
// that we send the packet straight away, so do not
// schedule the send
return allocateMissBuffer(pkt, curTick(), false);
- } else {
- // free the request and packet
- delete pkt;
}
}
}
diff --git a/src/mem/cache/prefetch/base.cc b/src/mem/cache/prefetch/base.cc
index 2746908..06d2b91 100644
--- a/src/mem/cache/prefetch/base.cc
+++ b/src/mem/cache/prefetch/base.cc
@@ -134,7 +134,15 @@
ADD_STAT(accuracy, statistics::units::Count::get(),
"accuracy of the prefetcher"),
ADD_STAT(coverage, statistics::units::Count::get(),
- "coverage brought by this prefetcher")
+ "coverage brought by this prefetcher"),
+ ADD_STAT(pfHitInCache, statistics::units::Count::get(),
+ "number of prefetches hitting in cache"),
+ ADD_STAT(pfHitInMSHR, statistics::units::Count::get(),
+ "number of prefetches hitting in a MSHR"),
+ ADD_STAT(pfHitInWB, statistics::units::Count::get(),
+ "number of prefetches hit in the Write Buffer"),
+ ADD_STAT(pfLate, statistics::units::Count::get(),
+ "number of late prefetches (hitting in cache, MSHR or WB)")
{
using namespace statistics;
@@ -145,6 +153,8 @@
coverage.flags(total);
coverage = pfUseful / (pfUseful + demandMshrMisses);
+
+ pfLate = pfHitInCache + pfHitInMSHR + pfHitInWB;
}
bool
diff --git a/src/mem/cache/prefetch/base.hh b/src/mem/cache/prefetch/base.hh
index 20a2d70..f2a8207 100644
--- a/src/mem/cache/prefetch/base.hh
+++ b/src/mem/cache/prefetch/base.hh
@@ -343,6 +343,20 @@
statistics::Scalar pfUsefulButMiss;
statistics::Formula accuracy;
statistics::Formula coverage;
+
+ /** The number of times a HW-prefetch hits in cache. */
+ statistics::Scalar pfHitInCache;
+
+ /** The number of times a HW-prefetch hits in a MSHR. */
+ statistics::Scalar pfHitInMSHR;
+
+ /** The number of times a HW-prefetch hits
+ * in the Write Buffer (WB). */
+ statistics::Scalar pfHitInWB;
+
+ /** The number of times a HW-prefetch is late
+ * (hit in cache, MSHR, WB). */
+ statistics::Formula pfLate;
} prefetchStats;
/** Total prefetches issued */
@@ -385,6 +399,24 @@
prefetchStats.demandMshrMisses++;
}
+ void
+ pfHitInCache()
+ {
+ prefetchStats.pfHitInCache++;
+ }
+
+ void
+ pfHitInMSHR()
+ {
+ prefetchStats.pfHitInMSHR++;
+ }
+
+ void
+ pfHitInWB()
+ {
+ prefetchStats.pfHitInWB++;
+ }
+
/**
* Register probe points for this object.
*/
--
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Gerrit-Project: public/gem5
Gerrit-Branch: develop
Gerrit-Change-Id: Ia6d5294e8ce58b2b0aae2be98fd0cee83be73b8d
Gerrit-Change-Number: 47204
Gerrit-PatchSet: 9
Gerrit-Owner: Nathanael Premillieu <nathanael.premill...@huawei.com>
Gerrit-Reviewer: Daniel Carvalho <oda...@yahoo.com.br>
Gerrit-Reviewer: Jason Lowe-Power <power...@gmail.com>
Gerrit-Reviewer: Nathanael Premillieu <nathanael.premill...@huawei.com>
Gerrit-Reviewer: Nikos Nikoleris <nikos.nikole...@arm.com>
Gerrit-Reviewer: kokoro <noreply+kok...@google.com>
Gerrit-MessageType: merged
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