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diff --git a/src/mem/qos/policy_pf.cc b/src/mem/qos/policy_pf.cc
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+++ b/src/mem/qos/policy_pf.cc
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+/*
+ * Copyright (c) 2018 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.
+ *
+ * Author: Giacomo Travaglini
+ */
+
+#include "mem/qos/policy_pf.hh"
+
+#include "mem/request.hh"
+
+namespace QoS {
+
+PropFairPolicy::PropFairPolicy(const Params* p)
+  : Policy(p), weight(p->weight)
+{
+    fatal_if(weight < 0 || weight > 1,
+        "weight must be a value between 0 and 1");
+}
+
+PropFairPolicy::~PropFairPolicy()
+{}
+
+template <typename Master>
+void
+PropFairPolicy::initMaster(const Master master, const double score)
+{
+    MasterID m_id = memCtrl->system()->lookupMasterId(master);
+
+    assert(m_id != Request::invldMasterId);
+
+    // Setting the Initial score for the selected master.
+    history.push_back(std::make_pair(m_id, score));
+
+    fatal_if(history.size() > memCtrl->numPriorities(),
+        "Policy's maximum number of masters is currently dictated "
+        "by the maximum number of priorities\n");
+}
+
+void
+PropFairPolicy::initMasterName(const std::string master, const double score)
+{
+    initMaster(master, score);
+}
+
+void
+PropFairPolicy::initMasterObj(const SimObject* master, const double score)
+{
+    initMaster(master, score);
+}
+
+double
+PropFairPolicy::updateScore(
+    const double old_score, const uint64_t served_bytes) const
+{
+    return ((1.0 - weight) * old_score) + (weight * served_bytes);
+}
+
+uint8_t
+PropFairPolicy::schedule(const MasterID pkt_mid, const uint64_t pkt_size)
+{
+    auto sort_pred =
+    [] (const MasterHistory& lhs, const MasterHistory& rhs)
+    { return lhs.second > rhs.second; };
+
+    // Sorting in reverse in base of personal history:
+    // First elements have higher history/score -> lower priority.
+    // The qos priority is the position in the sorted vector.
+    std::sort(history.begin(), history.end(), sort_pred);
+
+    const double served_bytes = static_cast<double>(pkt_size);
+
+    uint8_t pkt_priority = 0;
+    for (auto m_hist = history.begin(); m_hist != history.end(); m_hist++) {
+
+        MasterID curr_mid = m_hist->first;
+        double& curr_score = m_hist->second;
+
+        if (curr_mid == pkt_mid) {
+            // The qos priority is the position in the sorted vector.
+            pkt_priority = std::distance(history.begin(), m_hist);
+
+            curr_score = updateScore(curr_score, served_bytes);
+        } else {
+            curr_score = updateScore(curr_score, 0);
+        }
+    }
+
+    return pkt_priority;
+}
+
+} // namespace QoS
+
+QoS::PropFairPolicy *
+QoSPropFairPolicyParams::create()
+{
+    return new QoS::PropFairPolicy(this);
+}