commit ea6b0a03d3a272abbbdf74db78bcad13651e1d79
author huangjs <jiasen.hjs@alibaba-inc.com> Tue Nov 23 13:44:38 2021 +0800
committer Huang Jiasen <jiasen.hjs@alibaba-inc.com> Tue Nov 30 02:59:05 2021 +0000
tree c46d8e51e85202cc025ba1942d479b9e284ef08d
parent 39584edc7225a9ce24767d5f62403e90e2e63b2e

mem: Setup stats for Cache hitLatency

Change-Id: I18de75d3b6c4ce1784b90653e2d132ffecf1b1af
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/53103
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>

src/mem/cache/base.cc

diff --git a/src/mem/cache/base.cc b/src/mem/cache/base.cc
index f97c30a..dc21151 100644
--- a/src/mem/cache/base.cc
+++ b/src/mem/cache/base.cc
@@ -1954,6 +1954,8 @@
                ("number of " + name + " hits").c_str()),
       ADD_STAT(misses, statistics::units::Count::get(),
                ("number of " + name + " misses").c_str()),
+      ADD_STAT(hitLatency, statistics::units::Tick::get(),
+               ("number of " + name + " hit ticks").c_str()),
       ADD_STAT(missLatency, statistics::units::Tick::get(),
                ("number of " + name + " miss ticks").c_str()),
       ADD_STAT(accesses, statistics::units::Count::get(),
@@ -2010,6 +2012,15 @@
         misses.subname(i, system->getRequestorName(i));
     }
 
+    // Hit latency statistics
+    hitLatency
+        .init(max_requestors)
+        .flags(total | nozero | nonan)
+        ;
+    for (int i = 0; i < max_requestors; i++) {
+        hitLatency.subname(i, system->getRequestorName(i));
+    }
+
     // Miss latency statistics
     missLatency
         .init(max_requestors)
@@ -2116,6 +2127,10 @@
              "number of demand (read+write) hits"),
     ADD_STAT(overallHits, statistics::units::Count::get(),
              "number of overall hits"),
+    ADD_STAT(demandHitLatency, statistics::units::Tick::get(),
+             "number of demand (read+write) hit ticks"),
+    ADD_STAT(overallHitLatency, statistics::units::Tick::get(),
+            "number of overall hit ticks"),
     ADD_STAT(demandMisses, statistics::units::Count::get(),
              "number of demand (read+write) misses"),
     ADD_STAT(overallMisses, statistics::units::Count::get(),
@@ -2250,6 +2265,17 @@
         overallMissLatency.subname(i, system->getRequestorName(i));
     }
 
+    demandHitLatency.flags(total | nozero | nonan);
+    demandHitLatency = SUM_DEMAND(hitLatency);
+    for (int i = 0; i < max_requestors; i++) {
+        demandHitLatency.subname(i, system->getRequestorName(i));
+    }
+    overallHitLatency.flags(total | nozero | nonan);
+    overallHitLatency = demandHitLatency + SUM_NON_DEMAND(hitLatency);
+    for (int i = 0; i < max_requestors; i++) {
+        overallHitLatency.subname(i, system->getRequestorName(i));
+    }
+
     demandAccesses.flags(total | nozero | nonan);
     demandAccesses = demandHits + demandMisses;
     for (int i = 0; i < max_requestors; i++) {

src/mem/cache/base.hh

diff --git a/src/mem/cache/base.hh b/src/mem/cache/base.hh
index 988a678..0dc64e1 100644
--- a/src/mem/cache/base.hh
+++ b/src/mem/cache/base.hh
@@ -1006,6 +1006,11 @@
             @sa Packet::Command */
         statistics::Vector misses;
         /**
+         * Total number of cycles per thread/command spent waiting for a hit.
+         * Used to calculate the average hit latency.
+         */
+        statistics::Vector hitLatency;
+        /**
          * Total number of cycles per thread/command spent waiting for a miss.
          * Used to calculate the average miss latency.
          */
@@ -1050,6 +1055,10 @@
         statistics::Formula demandHits;
         /** Number of hit for all accesses. */
         statistics::Formula overallHits;
+        /** Total number of cycles spent waiting for demand hits. */
+        statistics::Formula demandHitLatency;
+        /** Total number of cycles spent waiting for all hits. */
+        statistics::Formula overallHitLatency;
 
         /** Number of misses for demand accesses. */
         statistics::Formula demandMisses;