diff --git a/lmkd/lmkd.c b/lmkd/lmkd.c
index 166edb6..59f17f2 100644
--- a/lmkd/lmkd.c
+++ b/lmkd/lmkd.c
@@ -793,24 +793,31 @@
 }
 
 static int memory_stat_parse(struct memory_stat *mem_st,  int pid, uid_t uid) {
-   FILE *fp;
-   char buf[PATH_MAX];
+    FILE *fp;
+    char buf[PATH_MAX];
 
-   snprintf(buf, sizeof(buf), MEMCG_PROCESS_MEMORY_STAT_PATH, uid, pid);
+    /*
+     * Per-application memory.stat files are available only when
+     * per-application memcgs are enabled.
+     */
+    if (!per_app_memcg)
+        return -1;
 
-   fp = fopen(buf, "r");
+    snprintf(buf, sizeof(buf), MEMCG_PROCESS_MEMORY_STAT_PATH, uid, pid);
 
-   if (fp == NULL) {
-       ALOGE("%s open failed: %s", buf, strerror(errno));
-       return -1;
-   }
+    fp = fopen(buf, "r");
 
-   while (fgets(buf, PAGE_SIZE, fp) != NULL ) {
-       memory_stat_parse_line(buf, mem_st);
-   }
-   fclose(fp);
+    if (fp == NULL) {
+        ALOGE("%s open failed: %s", buf, strerror(errno));
+        return -1;
+    }
 
-   return 0;
+    while (fgets(buf, PAGE_SIZE, fp) != NULL ) {
+        memory_stat_parse_line(buf, mem_st);
+    }
+    fclose(fp);
+
+    return 0;
 }
 #endif
 
diff --git a/rootdir/etc/public.libraries.android.txt b/rootdir/etc/public.libraries.android.txt
index e20b95d..2a51d53 100644
--- a/rootdir/etc/public.libraries.android.txt
+++ b/rootdir/etc/public.libraries.android.txt
@@ -1,6 +1,7 @@
 # See https://android.googlesource.com/platform/ndk/+/master/docs/PlatformApis.md
 libandroid.so
 libaaudio.so
+libamidi.so
 libc.so
 libcamera2ndk.so
 libdl.so
diff --git a/rootdir/etc/public.libraries.iot.txt b/rootdir/etc/public.libraries.iot.txt
index ff0813d..6690770 100644
--- a/rootdir/etc/public.libraries.iot.txt
+++ b/rootdir/etc/public.libraries.iot.txt
@@ -2,6 +2,7 @@
 libandroid.so
 libandroidthings.so
 libaaudio.so
+libamidi.so
 libc.so
 libcamera2ndk.so
 libdl.so
diff --git a/rootdir/etc/public.libraries.wear.txt b/rootdir/etc/public.libraries.wear.txt
index 3c46094..56055ba 100644
--- a/rootdir/etc/public.libraries.wear.txt
+++ b/rootdir/etc/public.libraries.wear.txt
@@ -1,6 +1,7 @@
 # See https://android.googlesource.com/platform/ndk/+/master/docs/PlatformApis.md
 libandroid.so
 libaaudio.so
+libamidi.so
 libc.so
 libcamera2ndk.so
 libdl.so
diff --git a/storaged/include/storaged_uid_monitor.h b/storaged/include/storaged_uid_monitor.h
index 3a718fa..fffb3d2 100644
--- a/storaged/include/storaged_uid_monitor.h
+++ b/storaged/include/storaged_uid_monitor.h
@@ -68,31 +68,33 @@
 
 struct uid_record {
     string name;
-    struct uid_io_usage ios;
+    uid_io_usage ios;
 };
 
 struct uid_records {
     uint64_t start_ts;
-    vector<struct uid_record> entries;
+    vector<uid_record> entries;
 };
 
 class uid_monitor {
 private:
     FRIEND_TEST(storaged_test, uid_monitor);
+    FRIEND_TEST(storaged_test, load_uid_io_proto);
+
     // last dump from /proc/uid_io/stats, uid -> uid_info
-    unordered_map<uint32_t, uid_info> last_uid_io_stats;
+    unordered_map<uint32_t, uid_info> last_uid_io_stats_;
     // current io usage for next report, app name -> uid_io_usage
-    unordered_map<string, struct uid_io_usage> curr_io_stats;
+    unordered_map<string, uid_io_usage> curr_io_stats_;
     // io usage records, end timestamp -> {start timestamp, vector of records}
-    map<uint64_t, struct uid_records> io_history;
+    map<uint64_t, uid_records> io_history_;
     // charger ON/OFF
-    charger_stat_t charger_stat;
+    charger_stat_t charger_stat_;
     // protects curr_io_stats, last_uid_io_stats, records and charger_stat
-    Mutex uidm_mutex;
+    Mutex uidm_mutex_;
     // start time for IO records
-    uint64_t start_ts;
+    uint64_t start_ts_;
     // true if UID_IO_STATS_PATH is accessible
-    const bool enable;
+    const bool enabled_;
 
     // reads from /proc/uid_io/stats
     unordered_map<uint32_t, uid_info> get_uid_io_stats_locked();
@@ -103,6 +105,10 @@
     // writes io_history to protobuf
     void update_uid_io_proto(unordered_map<int, StoragedProto>* protos);
 
+    // Ensure that io_history_ can append |n| items without exceeding
+    // MAX_UID_RECORDS_SIZE in size.
+    void maybe_shrink_history_for_items(size_t nitems);
+
 public:
     uid_monitor();
     // called by storaged main thread
@@ -110,16 +116,20 @@
     // called by storaged -u
     unordered_map<uint32_t, uid_info> get_uid_io_stats();
     // called by dumpsys
-    map<uint64_t, struct uid_records> dump(
+    map<uint64_t, uid_records> dump(
         double hours, uint64_t threshold, bool force_report);
     // called by battery properties listener
     void set_charger_state(charger_stat_t stat);
     // called by storaged periodic_chore or dump with force_report
-    bool enabled() { return enable; };
+    bool enabled() { return enabled_; };
     void report(unordered_map<int, StoragedProto>* protos);
     // restores io_history from protobuf
-    void load_uid_io_proto(const UidIOUsage& proto);
+    void load_uid_io_proto(userid_t user_id, const UidIOUsage& proto);
     void clear_user_history(userid_t user_id);
+
+    map<uint64_t, uid_records>& io_history() { return io_history_; }
+
+    static constexpr int MAX_UID_RECORDS_SIZE = 1000 * 48; // 1000 uids in 48 hours
 };
 
 #endif /* _STORAGED_UID_MONITOR_H_ */
diff --git a/storaged/storaged.cpp b/storaged/storaged.cpp
index f346c38..77c6167 100644
--- a/storaged/storaged.cpp
+++ b/storaged/storaged.cpp
@@ -194,7 +194,7 @@
         return;
     }
 
-    mUidm.load_uid_io_proto(proto.uid_io_usage());
+    mUidm.load_uid_io_proto(user_id, proto.uid_io_usage());
 
     if (user_id == USER_SYSTEM) {
         storage_info->load_perf_history_proto(proto.perf_history());
diff --git a/storaged/storaged_uid_monitor.cpp b/storaged/storaged_uid_monitor.cpp
index 5745782..55380ba 100644
--- a/storaged/storaged_uid_monitor.cpp
+++ b/storaged/storaged_uid_monitor.cpp
@@ -21,6 +21,7 @@
 
 #include <string>
 #include <unordered_map>
+#include <unordered_set>
 
 #include <android/content/pm/IPackageManagerNative.h>
 #include <android-base/file.h>
@@ -50,7 +51,7 @@
 
 std::unordered_map<uint32_t, uid_info> uid_monitor::get_uid_io_stats()
 {
-    Mutex::Autolock _l(uidm_mutex);
+    Mutex::Autolock _l(uidm_mutex_);
     return get_uid_io_stats_locked();
 };
 
@@ -178,10 +179,10 @@
             uid_io_stats[u.uid].name = std::to_string(u.uid);
             uids.push_back(u.uid);
             uid_names.push_back(&uid_io_stats[u.uid].name);
-            if (last_uid_io_stats.find(u.uid) == last_uid_io_stats.end()) {
+            if (last_uid_io_stats_.find(u.uid) == last_uid_io_stats_.end()) {
                 refresh_uid_names = true;
             } else {
-                uid_io_stats[u.uid].name = last_uid_io_stats[u.uid].name;
+                uid_io_stats[u.uid].name = last_uid_io_stats_[u.uid].name;
             }
         } else {
             task_info t;
@@ -200,8 +201,6 @@
 
 namespace {
 
-const int MAX_UID_RECORDS_SIZE = 1000 * 48; // 1000 uids in 48 hours
-
 inline size_t history_size(
     const std::map<uint64_t, struct uid_records>& history)
 {
@@ -218,12 +217,12 @@
 {
     // remove records more than 5 days old
     if (curr_ts > 5 * DAY_TO_SEC) {
-        auto it = io_history.lower_bound(curr_ts - 5 * DAY_TO_SEC);
-        io_history.erase(io_history.begin(), it);
+        auto it = io_history_.lower_bound(curr_ts - 5 * DAY_TO_SEC);
+        io_history_.erase(io_history_.begin(), it);
     }
 
     struct uid_records new_records;
-    for (const auto& p : curr_io_stats) {
+    for (const auto& p : curr_io_stats_) {
         struct uid_record record = {};
         record.name = p.first;
         if (!p.second.uid_ios.is_zero()) {
@@ -237,23 +236,26 @@
         }
     }
 
-    curr_io_stats.clear();
-    new_records.start_ts = start_ts;
-    start_ts = curr_ts;
+    curr_io_stats_.clear();
+    new_records.start_ts = start_ts_;
+    start_ts_ = curr_ts;
 
     if (new_records.entries.empty())
       return;
 
     // make some room for new records
-    ssize_t overflow = history_size(io_history) +
-        new_records.entries.size() - MAX_UID_RECORDS_SIZE;
-    while (overflow > 0 && io_history.size() > 0) {
-        auto del_it = io_history.begin();
-        overflow -= del_it->second.entries.size();
-        io_history.erase(io_history.begin());
-    }
+    maybe_shrink_history_for_items(new_records.entries.size());
 
-    io_history[curr_ts] = new_records;
+    io_history_[curr_ts] = new_records;
+}
+
+void uid_monitor::maybe_shrink_history_for_items(size_t nitems) {
+    ssize_t overflow = history_size(io_history_) + nitems - MAX_UID_RECORDS_SIZE;
+    while (overflow > 0 && io_history_.size() > 0) {
+        auto del_it = io_history_.begin();
+        overflow -= del_it->second.entries.size();
+        io_history_.erase(io_history_.begin());
+    }
 }
 
 std::map<uint64_t, struct uid_records> uid_monitor::dump(
@@ -263,7 +265,7 @@
         report(nullptr);
     }
 
-    Mutex::Autolock _l(uidm_mutex);
+    Mutex::Autolock _l(uidm_mutex_);
 
     std::map<uint64_t, struct uid_records> dump_records;
     uint64_t first_ts = 0;
@@ -272,7 +274,7 @@
         first_ts = time(NULL) - hours * HOUR_TO_SEC;
     }
 
-    for (auto it = io_history.lower_bound(first_ts); it != io_history.end(); ++it) {
+    for (auto it = io_history_.lower_bound(first_ts); it != io_history_.end(); ++it) {
         const std::vector<struct uid_record>& recs = it->second.entries;
         struct uid_records filtered;
 
@@ -311,29 +313,29 @@
 
     for (const auto& it : uid_io_stats) {
         const uid_info& uid = it.second;
-        if (curr_io_stats.find(uid.name) == curr_io_stats.end()) {
-            curr_io_stats[uid.name] = {};
+        if (curr_io_stats_.find(uid.name) == curr_io_stats_.end()) {
+            curr_io_stats_[uid.name] = {};
         }
 
-        struct uid_io_usage& usage = curr_io_stats[uid.name];
+        struct uid_io_usage& usage = curr_io_stats_[uid.name];
         usage.user_id = multiuser_get_user_id(uid.uid);
 
         int64_t fg_rd_delta = uid.io[FOREGROUND].read_bytes -
-            last_uid_io_stats[uid.uid].io[FOREGROUND].read_bytes;
+            last_uid_io_stats_[uid.uid].io[FOREGROUND].read_bytes;
         int64_t bg_rd_delta = uid.io[BACKGROUND].read_bytes -
-            last_uid_io_stats[uid.uid].io[BACKGROUND].read_bytes;
+            last_uid_io_stats_[uid.uid].io[BACKGROUND].read_bytes;
         int64_t fg_wr_delta = uid.io[FOREGROUND].write_bytes -
-            last_uid_io_stats[uid.uid].io[FOREGROUND].write_bytes;
+            last_uid_io_stats_[uid.uid].io[FOREGROUND].write_bytes;
         int64_t bg_wr_delta = uid.io[BACKGROUND].write_bytes -
-            last_uid_io_stats[uid.uid].io[BACKGROUND].write_bytes;
+            last_uid_io_stats_[uid.uid].io[BACKGROUND].write_bytes;
 
-        usage.uid_ios.bytes[READ][FOREGROUND][charger_stat] +=
+        usage.uid_ios.bytes[READ][FOREGROUND][charger_stat_] +=
             (fg_rd_delta < 0) ? 0 : fg_rd_delta;
-        usage.uid_ios.bytes[READ][BACKGROUND][charger_stat] +=
+        usage.uid_ios.bytes[READ][BACKGROUND][charger_stat_] +=
             (bg_rd_delta < 0) ? 0 : bg_rd_delta;
-        usage.uid_ios.bytes[WRITE][FOREGROUND][charger_stat] +=
+        usage.uid_ios.bytes[WRITE][FOREGROUND][charger_stat_] +=
             (fg_wr_delta < 0) ? 0 : fg_wr_delta;
-        usage.uid_ios.bytes[WRITE][BACKGROUND][charger_stat] +=
+        usage.uid_ios.bytes[WRITE][BACKGROUND][charger_stat_] +=
             (bg_wr_delta < 0) ? 0 : bg_wr_delta;
 
         for (const auto& task_it : uid.tasks) {
@@ -341,34 +343,34 @@
             const pid_t pid = task_it.first;
             const std::string& comm = task_it.second.comm;
             int64_t task_fg_rd_delta = task.io[FOREGROUND].read_bytes -
-                last_uid_io_stats[uid.uid].tasks[pid].io[FOREGROUND].read_bytes;
+                last_uid_io_stats_[uid.uid].tasks[pid].io[FOREGROUND].read_bytes;
             int64_t task_bg_rd_delta = task.io[BACKGROUND].read_bytes -
-                last_uid_io_stats[uid.uid].tasks[pid].io[BACKGROUND].read_bytes;
+                last_uid_io_stats_[uid.uid].tasks[pid].io[BACKGROUND].read_bytes;
             int64_t task_fg_wr_delta = task.io[FOREGROUND].write_bytes -
-                last_uid_io_stats[uid.uid].tasks[pid].io[FOREGROUND].write_bytes;
+                last_uid_io_stats_[uid.uid].tasks[pid].io[FOREGROUND].write_bytes;
             int64_t task_bg_wr_delta = task.io[BACKGROUND].write_bytes -
-                last_uid_io_stats[uid.uid].tasks[pid].io[BACKGROUND].write_bytes;
+                last_uid_io_stats_[uid.uid].tasks[pid].io[BACKGROUND].write_bytes;
 
             io_usage& task_usage = usage.task_ios[comm];
-            task_usage.bytes[READ][FOREGROUND][charger_stat] +=
+            task_usage.bytes[READ][FOREGROUND][charger_stat_] +=
                 (task_fg_rd_delta < 0) ? 0 : task_fg_rd_delta;
-            task_usage.bytes[READ][BACKGROUND][charger_stat] +=
+            task_usage.bytes[READ][BACKGROUND][charger_stat_] +=
                 (task_bg_rd_delta < 0) ? 0 : task_bg_rd_delta;
-            task_usage.bytes[WRITE][FOREGROUND][charger_stat] +=
+            task_usage.bytes[WRITE][FOREGROUND][charger_stat_] +=
                 (task_fg_wr_delta < 0) ? 0 : task_fg_wr_delta;
-            task_usage.bytes[WRITE][BACKGROUND][charger_stat] +=
+            task_usage.bytes[WRITE][BACKGROUND][charger_stat_] +=
                 (task_bg_wr_delta < 0) ? 0 : task_bg_wr_delta;
         }
     }
 
-    last_uid_io_stats = uid_io_stats;
+    last_uid_io_stats_ = uid_io_stats;
 }
 
 void uid_monitor::report(unordered_map<int, StoragedProto>* protos)
 {
     if (!enabled()) return;
 
-    Mutex::Autolock _l(uidm_mutex);
+    Mutex::Autolock _l(uidm_mutex_);
 
     update_curr_io_stats_locked();
     add_records_locked(time(NULL));
@@ -408,7 +410,7 @@
 
 void uid_monitor::update_uid_io_proto(unordered_map<int, StoragedProto>* protos)
 {
-    for (const auto& item : io_history) {
+    for (const auto& item : io_history_) {
         const uint64_t& end_ts = item.first;
         const struct uid_records& recs = item.second;
         unordered_map<userid_t, UidIOItem*> user_items;
@@ -448,9 +450,9 @@
 
 void uid_monitor::clear_user_history(userid_t user_id)
 {
-    Mutex::Autolock _l(uidm_mutex);
+    Mutex::Autolock _l(uidm_mutex_);
 
-    for (auto& item : io_history) {
+    for (auto& item : io_history_) {
         vector<uid_record>* entries = &item.second.entries;
         entries->erase(
             remove_if(entries->begin(), entries->end(),
@@ -459,27 +461,42 @@
             entries->end());
     }
 
-    for (auto it = io_history.begin(); it != io_history.end(); ) {
+    for (auto it = io_history_.begin(); it != io_history_.end(); ) {
         if (it->second.entries.empty()) {
-            it = io_history.erase(it);
+            it = io_history_.erase(it);
         } else {
             it++;
         }
     }
 }
 
-void uid_monitor::load_uid_io_proto(const UidIOUsage& uid_io_proto)
+void uid_monitor::load_uid_io_proto(userid_t user_id, const UidIOUsage& uid_io_proto)
 {
     if (!enabled()) return;
 
-    Mutex::Autolock _l(uidm_mutex);
+    Mutex::Autolock _l(uidm_mutex_);
 
     for (const auto& item_proto : uid_io_proto.uid_io_items()) {
         const UidIORecords& records_proto = item_proto.records();
-        struct uid_records* recs = &io_history[item_proto.end_ts()];
+        struct uid_records* recs = &io_history_[item_proto.end_ts()];
+
+        // It's possible that the same uid_io_proto file gets loaded more than
+        // once, for example, if system_server crashes. In this case we avoid
+        // adding duplicate entries, so we build a quick way to check for
+        // duplicates.
+        std::unordered_set<std::string> existing_uids;
+        for (const auto& rec : recs->entries) {
+            if (rec.ios.user_id == user_id) {
+                existing_uids.emplace(rec.name);
+            }
+        }
 
         recs->start_ts = records_proto.start_ts();
         for (const auto& rec_proto : records_proto.entries()) {
+            if (existing_uids.find(rec_proto.uid_name()) != existing_uids.end()) {
+                continue;
+            }
+
             struct uid_record record;
             record.name = rec_proto.uid_name();
             record.ios.user_id = rec_proto.user_id();
@@ -492,29 +509,35 @@
             }
             recs->entries.push_back(record);
         }
+
+        // We already added items, so this will just cull down to the maximum
+        // length. We do not remove anything if there is only one entry.
+        if (io_history_.size() > 1) {
+            maybe_shrink_history_for_items(0);
+        }
     }
 }
 
 void uid_monitor::set_charger_state(charger_stat_t stat)
 {
-    Mutex::Autolock _l(uidm_mutex);
+    Mutex::Autolock _l(uidm_mutex_);
 
-    if (charger_stat == stat) {
+    if (charger_stat_ == stat) {
         return;
     }
 
     update_curr_io_stats_locked();
-    charger_stat = stat;
+    charger_stat_ = stat;
 }
 
 void uid_monitor::init(charger_stat_t stat)
 {
-    charger_stat = stat;
+    charger_stat_ = stat;
 
-    start_ts = time(NULL);
-    last_uid_io_stats = get_uid_io_stats();
+    start_ts_ = time(NULL);
+    last_uid_io_stats_ = get_uid_io_stats();
 }
 
 uid_monitor::uid_monitor()
-    : enable(!access(UID_IO_STATS_PATH, R_OK)) {
+    : enabled_(!access(UID_IO_STATS_PATH, R_OK)) {
 }
diff --git a/storaged/tests/storaged_test.cpp b/storaged/tests/storaged_test.cpp
index ec47b65..64009c2 100644
--- a/storaged/tests/storaged_test.cpp
+++ b/storaged/tests/storaged_test.cpp
@@ -443,8 +443,9 @@
 
 TEST(storaged_test, uid_monitor) {
     uid_monitor uidm;
+    auto& io_history = uidm.io_history();
 
-    uidm.io_history[200] = {
+    io_history[200] = {
         .start_ts = 100,
         .entries = {
             { "app1", {
@@ -466,7 +467,7 @@
         },
     };
 
-    uidm.io_history[300] = {
+    io_history[300] = {
         .start_ts = 200,
         .entries = {
             { "app1", {
@@ -526,9 +527,9 @@
     EXPECT_EQ(user_1_item_1.records().entries(0).user_id(), 1UL);
     EXPECT_EQ(user_1_item_1.records().entries(0).uid_io().wr_fg_chg_off(), 1000UL);
 
-    uidm.io_history.clear();
+    io_history.clear();
 
-    uidm.io_history[300] = {
+    io_history[300] = {
         .start_ts = 200,
         .entries = {
             { "app1", {
@@ -539,7 +540,7 @@
         },
     };
 
-    uidm.io_history[400] = {
+    io_history[400] = {
         .start_ts = 300,
         .entries = {
             { "app1", {
@@ -550,16 +551,16 @@
         },
     };
 
-    uidm.load_uid_io_proto(protos[0].uid_io_usage());
-    uidm.load_uid_io_proto(protos[1].uid_io_usage());
+    uidm.load_uid_io_proto(0, protos[0].uid_io_usage());
+    uidm.load_uid_io_proto(1, protos[1].uid_io_usage());
 
-    EXPECT_EQ(uidm.io_history.size(), 3UL);
-    EXPECT_EQ(uidm.io_history.count(200), 1UL);
-    EXPECT_EQ(uidm.io_history.count(300), 1UL);
-    EXPECT_EQ(uidm.io_history.count(400), 1UL);
+    EXPECT_EQ(io_history.size(), 3UL);
+    EXPECT_EQ(io_history.count(200), 1UL);
+    EXPECT_EQ(io_history.count(300), 1UL);
+    EXPECT_EQ(io_history.count(400), 1UL);
 
-    EXPECT_EQ(uidm.io_history[200].start_ts, 100UL);
-    const vector<struct uid_record>& entries_0 = uidm.io_history[200].entries;
+    EXPECT_EQ(io_history[200].start_ts, 100UL);
+    const vector<struct uid_record>& entries_0 = io_history[200].entries;
     EXPECT_EQ(entries_0.size(), 3UL);
     EXPECT_EQ(entries_0[0].name, "app1");
     EXPECT_EQ(entries_0[0].ios.user_id, 0UL);
@@ -572,8 +573,8 @@
     EXPECT_EQ(entries_0[2].ios.uid_ios.bytes[WRITE][FOREGROUND][CHARGER_ON], 1000UL);
     EXPECT_EQ(entries_0[2].ios.uid_ios.bytes[READ][FOREGROUND][CHARGER_ON], 1000UL);
 
-    EXPECT_EQ(uidm.io_history[300].start_ts, 200UL);
-    const vector<struct uid_record>& entries_1 = uidm.io_history[300].entries;
+    EXPECT_EQ(io_history[300].start_ts, 200UL);
+    const vector<struct uid_record>& entries_1 = io_history[300].entries;
     EXPECT_EQ(entries_1.size(), 3UL);
     EXPECT_EQ(entries_1[0].name, "app1");
     EXPECT_EQ(entries_1[0].ios.user_id, 0UL);
@@ -585,8 +586,8 @@
     EXPECT_EQ(entries_1[2].ios.user_id, 1UL);
     EXPECT_EQ(entries_1[2].ios.uid_ios.bytes[WRITE][FOREGROUND][CHARGER_OFF], 1000UL);
 
-    EXPECT_EQ(uidm.io_history[400].start_ts, 300UL);
-    const vector<struct uid_record>& entries_2 = uidm.io_history[400].entries;
+    EXPECT_EQ(io_history[400].start_ts, 300UL);
+    const vector<struct uid_record>& entries_2 = io_history[400].entries;
     EXPECT_EQ(entries_2.size(), 1UL);
     EXPECT_EQ(entries_2[0].name, "app1");
     EXPECT_EQ(entries_2[0].ios.user_id, 0UL);
@@ -615,14 +616,71 @@
 
     uidm.clear_user_history(0);
 
-    EXPECT_EQ(uidm.io_history.size(), 2UL);
-    EXPECT_EQ(uidm.io_history.count(200), 1UL);
-    EXPECT_EQ(uidm.io_history.count(300), 1UL);
+    EXPECT_EQ(io_history.size(), 2UL);
+    EXPECT_EQ(io_history.count(200), 1UL);
+    EXPECT_EQ(io_history.count(300), 1UL);
 
-    EXPECT_EQ(uidm.io_history[200].entries.size(), 1UL);
-    EXPECT_EQ(uidm.io_history[300].entries.size(), 1UL);
+    EXPECT_EQ(io_history[200].entries.size(), 1UL);
+    EXPECT_EQ(io_history[300].entries.size(), 1UL);
 
     uidm.clear_user_history(1);
 
-    EXPECT_EQ(uidm.io_history.size(), 0UL);
+    EXPECT_EQ(io_history.size(), 0UL);
+}
+
+TEST(storaged_test, load_uid_io_proto) {
+    uid_monitor uidm;
+    auto& io_history = uidm.io_history();
+
+    static const uint64_t kProtoTime = 200;
+    io_history[kProtoTime] = {
+        .start_ts = 100,
+        .entries = {
+            { "app1", {
+                .user_id = 0,
+                .uid_ios.bytes[WRITE][FOREGROUND][CHARGER_ON] = 1000,
+              }
+            },
+            { "app2", {
+                .user_id = 0,
+                .uid_ios.bytes[READ][FOREGROUND][CHARGER_OFF] = 2000,
+              }
+            },
+            { "app3", {
+                .user_id = 0,
+                .uid_ios.bytes[READ][FOREGROUND][CHARGER_OFF] = 3000,
+              }
+            },
+        },
+    };
+
+    unordered_map<int, StoragedProto> protos;
+    uidm.update_uid_io_proto(&protos);
+    ASSERT_EQ(protos.size(), size_t(1));
+
+    // Loading the same proto many times should not add duplicate entries.
+    UidIOUsage user_0 = protos[0].uid_io_usage();
+    for (size_t i = 0; i < 10000; i++) {
+        uidm.load_uid_io_proto(0, user_0);
+    }
+    ASSERT_EQ(io_history.size(), size_t(1));
+    ASSERT_EQ(io_history[kProtoTime].entries.size(), size_t(3));
+
+    // Create duplicate entries until we go over the limit.
+    auto record = io_history[kProtoTime];
+    io_history.clear();
+    for (size_t i = 0; i < uid_monitor::MAX_UID_RECORDS_SIZE * 2; i++) {
+        if (i == kProtoTime) {
+            continue;
+        }
+        io_history[i] = record;
+    }
+    ASSERT_GT(io_history.size(), size_t(uid_monitor::MAX_UID_RECORDS_SIZE));
+
+    // After loading, the history should be truncated.
+    for (auto& item : *user_0.mutable_uid_io_items()) {
+        item.set_end_ts(io_history.size());
+    }
+    uidm.load_uid_io_proto(0, user_0);
+    ASSERT_LE(io_history.size(), size_t(uid_monitor::MAX_UID_RECORDS_SIZE));
 }