mem: Move eraseIfNullEntry to when holder is updated
The entry should only be tested for deletion when holder is updated.
Change-Id: I5a10b6fa876912709b7467860d43c23c60f38568
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/19750
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
diff --git a/src/mem/snoop_filter.cc b/src/mem/snoop_filter.cc
index d368dd8..b0422e2 100644
--- a/src/mem/snoop_filter.cc
+++ b/src/mem/snoop_filter.cc
@@ -206,9 +206,6 @@
SnoopItem& sf_item = sf_it->second;
- DPRINTF(SnoopFilter, "%s: old SF value %x.%x\n",
- __func__, sf_item.requested, sf_item.holder);
-
SnoopMask interested = (sf_item.holder | sf_item.requested);
totSnoops++;
@@ -232,13 +229,14 @@
// Early clear of the holder, if no other request is currently going on
// @todo: This should possibly be updated even though we do not filter
// upward snoops
+ DPRINTF(SnoopFilter, "%s: old SF value %x.%x\n",
+ __func__, sf_item.requested, sf_item.holder);
sf_item.holder = 0;
+ DPRINTF(SnoopFilter, "%s: new SF value %x.%x\n",
+ __func__, sf_item.requested, sf_item.holder);
+ eraseIfNullEntry(sf_it);
}
- eraseIfNullEntry(sf_it);
- DPRINTF(SnoopFilter, "%s: new SF value %x.%x interest: %x \n",
- __func__, sf_item.requested, sf_item.holder, interested);
-
return snoopSelected(maskToPortList(interested), lookupLatency);
}
@@ -320,21 +318,20 @@
if (!is_hit)
return;
- SnoopItem& sf_item = sf_it->second;
-
- DPRINTF(SnoopFilter, "%s: old SF value %x.%x\n",
- __func__, sf_item.requested, sf_item.holder);
-
// If the snoop response has no sharers the line is passed in
// Modified state, and we know that there are no other copies, or
// they will all be invalidated imminently
if (!cpkt->hasSharers()) {
- sf_item.holder = 0;
- }
- DPRINTF(SnoopFilter, "%s: new SF value %x.%x\n",
- __func__, sf_item.requested, sf_item.holder);
- eraseIfNullEntry(sf_it);
+ SnoopItem& sf_item = sf_it->second;
+ DPRINTF(SnoopFilter, "%s: old SF value %x.%x\n",
+ __func__, sf_item.requested, sf_item.holder);
+ sf_item.holder = 0;
+ DPRINTF(SnoopFilter, "%s: new SF value %x.%x\n",
+ __func__, sf_item.requested, sf_item.holder);
+
+ eraseIfNullEntry(sf_it);
+ }
}
void
