mem-cache: count pf filtered by demand to the same cache line
Add a stat to count how many prefetch request are filtered in the
prefetch queue becasue a demand is going to the same cache line
Also adding a corresponding debug statement for when it happens
Change-Id: I52475f19bd109c135b7259d08d5f5c0b5fd90ee5
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/47203
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
diff --git a/src/mem/cache/prefetch/queued.cc b/src/mem/cache/prefetch/queued.cc
index a2e1952..dec71f2 100644
--- a/src/mem/cache/prefetch/queued.cc
+++ b/src/mem/cache/prefetch/queued.cc
@@ -178,8 +178,13 @@
while (itr != pfq.end()) {
if (itr->pfInfo.getAddr() == blk_addr &&
itr->pfInfo.isSecure() == is_secure) {
+ DPRINTF(HWPrefetch, "Removing pf candidate addr: %#x "
+ "(cl: %#x), demand request going to the same addr\n",
+ itr->pfInfo.getAddr(),
+ blockAddress(itr->pfInfo.getAddr()));
delete itr->pkt;
itr = pfq.erase(itr);
+ statsQueued.pfRemovedDemand++;
} else {
++itr;
}
@@ -258,6 +263,9 @@
"number of redundant prefetches already in prefetch queue"),
ADD_STAT(pfInCache, statistics::units::Count::get(),
"number of redundant prefetches already in cache/mshr dropped"),
+ ADD_STAT(pfRemovedDemand, statistics::units::Count::get(),
+ "number of prefetches dropped due to a demand for the same "
+ "address"),
ADD_STAT(pfRemovedFull, statistics::units::Count::get(),
"number of prefetches dropped due to prefetch queue size"),
ADD_STAT(pfSpanPage, statistics::units::Count::get(),
diff --git a/src/mem/cache/prefetch/queued.hh b/src/mem/cache/prefetch/queued.hh
index d710bc0..1062630 100644
--- a/src/mem/cache/prefetch/queued.hh
+++ b/src/mem/cache/prefetch/queued.hh
@@ -182,6 +182,7 @@
statistics::Scalar pfIdentified;
statistics::Scalar pfBufferHit;
statistics::Scalar pfInCache;
+ statistics::Scalar pfRemovedDemand;
statistics::Scalar pfRemovedFull;
statistics::Scalar pfSpanPage;
} statsQueued;