diff --git a/libmeminfo/tools/Android.bp b/libmeminfo/tools/Android.bp
index 0870130..7c41660 100644
--- a/libmeminfo/tools/Android.bp
+++ b/libmeminfo/tools/Android.bp
@@ -25,3 +25,18 @@
         "libmeminfo",
     ],
 }
+
+cc_binary {
+    name: "procrank2",
+    cflags: [
+        "-Wall",
+        "-Werror",
+        "-Wno-unused-parameter",
+    ],
+
+    srcs: ["procrank.cpp"],
+    shared_libs: [
+        "libbase",
+        "libmeminfo",
+    ],
+}
diff --git a/libmeminfo/tools/procrank.cpp b/libmeminfo/tools/procrank.cpp
new file mode 100644
index 0000000..e39e7fa
--- /dev/null
+++ b/libmeminfo/tools/procrank.cpp
@@ -0,0 +1,530 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <dirent.h>
+#include <errno.h>
+#include <inttypes.h>
+#include <linux/kernel-page-flags.h>
+#include <linux/oom.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <iostream>
+#include <memory>
+#include <sstream>
+#include <vector>
+
+#include <android-base/file.h>
+#include <android-base/parseint.h>
+#include <android-base/stringprintf.h>
+#include <android-base/strings.h>
+
+#include <meminfo/procmeminfo.h>
+#include <meminfo/sysmeminfo.h>
+
+using ::android::meminfo::MemUsage;
+using ::android::meminfo::ProcMemInfo;
+
+struct ProcessRecord {
+  public:
+    ProcessRecord(pid_t pid, bool get_wss = false, uint64_t pgflags = 0, uint64_t pgflags_mask = 0)
+        : pid_(-1),
+          procmem_(nullptr),
+          oomadj_(OOM_SCORE_ADJ_MAX + 1),
+          cmdline_(""),
+          proportional_swap_(0),
+          unique_swap_(0),
+          zswap_(0) {
+        std::unique_ptr<ProcMemInfo> procmem =
+                std::make_unique<ProcMemInfo>(pid, get_wss, pgflags, pgflags_mask);
+        if (procmem == nullptr) {
+            std::cerr << "Failed to create ProcMemInfo for: " << pid << std::endl;
+            return;
+        }
+
+        std::string fname = ::android::base::StringPrintf("/proc/%d/oom_score_adj", pid);
+        auto oomscore_fp =
+                std::unique_ptr<FILE, decltype(&fclose)>{fopen(fname.c_str(), "re"), fclose};
+        if (oomscore_fp == nullptr) {
+            std::cerr << "Failed to open oom_score_adj file: " << fname << std::endl;
+            return;
+        }
+
+        if (fscanf(oomscore_fp.get(), "%d\n", &oomadj_) != 1) {
+            std::cerr << "Failed to read oomadj from: " << fname << std::endl;
+            return;
+        }
+
+        fname = ::android::base::StringPrintf("/proc/%d/cmdline", pid);
+        if (!::android::base::ReadFileToString(fname, &cmdline_)) {
+            std::cerr << "Failed to read cmdline from: " << fname << std::endl;
+            cmdline_ = "<unknown>";
+        }
+        // We deliberately don't read the proc/<pid>cmdline file directly into 'cmdline_'
+        // because of some processes showing up cmdlines that end with "0x00 0x0A 0x00"
+        // e.g. xtra-daemon, lowi-server
+        // The .c_str() assignment below then takes care of trimming the cmdline at the first
+        // 0x00. This is how original procrank worked (luckily)
+        cmdline_.resize(strlen(cmdline_.c_str()));
+        procmem_ = std::move(procmem);
+        pid_ = pid;
+    }
+
+    bool valid() const { return pid_ != -1; }
+
+    void CalculateSwap(const uint16_t* swap_offset_array, float zram_compression_ratio) {
+        const std::vector<uint16_t>& swp_offs = procmem_->SwapOffsets();
+        for (auto& off : swp_offs) {
+            proportional_swap_ += getpagesize() / swap_offset_array[off];
+            unique_swap_ += swap_offset_array[off] == 1 ? getpagesize() : 0;
+            zswap_ = proportional_swap_ * zram_compression_ratio;
+        }
+    }
+
+    // Getters
+    pid_t pid() const { return pid_; }
+    const std::string& cmdline() const { return cmdline_; }
+    int32_t oomadj() const { return oomadj_; }
+    uint64_t proportional_swap() const { return proportional_swap_; }
+    uint64_t unique_swap() const { return unique_swap_; }
+    uint64_t zswap() const { return zswap_; }
+
+    // Wrappers to ProcMemInfo
+    const std::vector<uint16_t>& SwapOffsets() const { return procmem_->SwapOffsets(); }
+    const MemUsage& Usage() const { return procmem_->Usage(); }
+    const MemUsage& Wss() const { return procmem_->Wss(); }
+
+  private:
+    pid_t pid_;
+    std::unique_ptr<ProcMemInfo> procmem_;
+    int32_t oomadj_;
+    std::string cmdline_;
+    uint64_t proportional_swap_;
+    uint64_t unique_swap_;
+    uint64_t zswap_;
+};
+
+// Show working set instead of memory consumption
+bool show_wss = false;
+// Reset working set of each process
+bool reset_wss = false;
+// Show per-process oom_score_adj column
+bool show_oomadj = false;
+// True if the device has swap enabled
+bool has_swap = false;
+// True, if device has zram enabled
+bool has_zram = false;
+// If zram is enabled, the compression ratio is zram used / swap used.
+float zram_compression_ratio = 0.0;
+// Sort process in reverse, default is descending
+bool reverse_sort = false;
+
+// Calculated total memory usage across all processes in the system
+uint64_t total_pss = 0;
+uint64_t total_uss = 0;
+uint64_t total_swap = 0;
+uint64_t total_pswap = 0;
+uint64_t total_uswap = 0;
+uint64_t total_zswap = 0;
+
+static void usage(const char* myname) {
+    std::cerr << "Usage: " << myname << " [ -W ] [ -v | -r | -p | -u | -s | -h ]" << std::endl
+              << "    -v  Sort by VSS." << std::endl
+              << "    -r  Sort by RSS." << std::endl
+              << "    -p  Sort by PSS." << std::endl
+              << "    -u  Sort by USS." << std::endl
+              << "    -s  Sort by swap." << std::endl
+              << "        (Default sort order is PSS.)" << std::endl
+              << "    -R  Reverse sort order (default is descending)." << std::endl
+              << "    -c  Only show cached (storage backed) pages" << std::endl
+              << "    -C  Only show non-cached (ram/swap backed) pages" << std::endl
+              << "    -k  Only show pages collapsed by KSM" << std::endl
+              << "    -w  Display statistics for working set only." << std::endl
+              << "    -W  Reset working set of all processes." << std::endl
+              << "    -o  Show and sort by oom score against lowmemorykiller thresholds."
+              << std::endl
+              << "    -h  Display this help screen." << std::endl;
+}
+
+static bool read_all_pids(std::vector<pid_t>* pids, std::function<bool(pid_t pid)> for_each_pid) {
+    pids->clear();
+    std::unique_ptr<DIR, int (*)(DIR*)> procdir(opendir("/proc"), closedir);
+    if (!procdir) return false;
+
+    struct dirent* dir;
+    pid_t pid;
+    while ((dir = readdir(procdir.get()))) {
+        if (!::android::base::ParseInt(dir->d_name, &pid)) continue;
+        if (!for_each_pid(pid)) return false;
+        pids->push_back(pid);
+    }
+
+    return true;
+}
+
+static bool count_swap_offsets(const ProcessRecord& proc, uint16_t* swap_offset_array,
+                               uint32_t size) {
+    const std::vector<uint16_t>& swp_offs = proc.SwapOffsets();
+    for (auto& off : swp_offs) {
+        if (off >= size) {
+            std::cerr << "swap offset " << off << " is out of bounds for process: " << proc.pid()
+                      << std::endl;
+            return false;
+        }
+
+        if (swap_offset_array[off] == USHRT_MAX) {
+            std::cerr << "swap offset " << off << " ref count overflow in process: " << proc.pid()
+                      << std::endl;
+            return false;
+        }
+
+        swap_offset_array[off]++;
+    }
+
+    return true;
+}
+
+static void print_header(std::stringstream& ss) {
+    ss.str("");
+    ss << ::android::base::StringPrintf("%5s  ", "PID");
+    if (show_oomadj) {
+        ss << ::android::base::StringPrintf("%5s  ", "oom");
+    }
+
+    if (show_wss) {
+        ss << ::android::base::StringPrintf("%7s  %7s  %7s  ", "WRss", "WPss", "WUss");
+        // now swap statistics here, working set pages by definition shouldn't end up in swap.
+    } else {
+        ss << ::android::base::StringPrintf("%8s  %7s  %7s  %7s  ", "Vss", "Rss", "Pss", "Uss");
+        if (has_swap) {
+            ss << ::android::base::StringPrintf("%7s  %7s  %7s  ", "Swap", "PSwap", "USwap");
+            if (has_zram) {
+                ss << ::android::base::StringPrintf("%7s  ", "ZSwap");
+            }
+        }
+    }
+
+    ss << "cmdline";
+}
+
+static void print_process_record(std::stringstream& ss, ProcessRecord& proc) {
+    ss << ::android::base::StringPrintf("%5d  ", proc.pid());
+    if (show_oomadj) {
+        ss << ::android::base::StringPrintf("%5d  ", proc.oomadj());
+    }
+
+    if (show_wss) {
+        ss << ::android::base::StringPrintf("%6" PRIu64 "K  %6" PRIu64 "K  %6" PRIu64 "K  ",
+                                            proc.Wss().rss / 1024, proc.Wss().pss / 1024,
+                                            proc.Wss().uss / 1024);
+    } else {
+        ss << ::android::base::StringPrintf("%7" PRIu64 "K  %6" PRIu64 "K  %6" PRIu64 "K  %6" PRIu64
+                                            "K  ",
+                                            proc.Usage().vss / 1024, proc.Usage().rss / 1024,
+                                            proc.Usage().pss / 1024, proc.Usage().uss / 1024);
+        if (has_swap) {
+            ss << ::android::base::StringPrintf("%6" PRIu64 "K  ", proc.Usage().swap / 1024);
+            ss << ::android::base::StringPrintf("%6" PRIu64 "K  ", proc.proportional_swap() / 1024);
+            ss << ::android::base::StringPrintf("%6" PRIu64 "K  ", proc.unique_swap() / 1024);
+            if (has_zram) {
+                ss << ::android::base::StringPrintf("%6" PRIu64 "K  ", (proc.zswap() / 1024));
+            }
+        }
+    }
+}
+
+static void print_processes(std::stringstream& ss, std::vector<ProcessRecord>& procs,
+                            uint16_t* swap_offset_array) {
+    for (auto& proc : procs) {
+        total_pss += show_wss ? proc.Wss().pss : proc.Usage().pss;
+        total_uss += show_wss ? proc.Wss().uss : proc.Usage().uss;
+        if (!show_wss && has_swap) {
+            proc.CalculateSwap(swap_offset_array, zram_compression_ratio);
+            total_swap += proc.Usage().swap;
+            total_pswap += proc.proportional_swap();
+            total_uswap += proc.unique_swap();
+            if (has_zram) {
+                total_zswap += proc.zswap();
+            }
+        }
+
+        print_process_record(ss, proc);
+        ss << proc.cmdline() << std::endl;
+    }
+}
+
+static void print_separator(std::stringstream& ss) {
+    ss << ::android::base::StringPrintf("%5s  ", "");
+    if (show_oomadj) {
+        ss << ::android::base::StringPrintf("%5s  ", "");
+    }
+
+    if (show_wss) {
+        ss << ::android::base::StringPrintf("%7s  %7s  %7s  ", "", "------", "------");
+    } else {
+        ss << ::android::base::StringPrintf("%8s  %7s  %7s  %7s  ", "", "", "------", "------");
+        if (has_swap) {
+            ss << ::android::base::StringPrintf("%7s  %7s  %7s  ", "------", "------", "------");
+            if (has_zram) {
+                ss << ::android::base::StringPrintf("%7s  ", "------");
+            }
+        }
+    }
+
+    ss << ::android::base::StringPrintf("%s", "------");
+}
+
+static void print_totals(std::stringstream& ss) {
+    ss << ::android::base::StringPrintf("%5s  ", "");
+    if (show_oomadj) {
+        ss << ::android::base::StringPrintf("%5s  ", "");
+    }
+
+    if (show_wss) {
+        ss << ::android::base::StringPrintf("%7s  %6" PRIu64 "K  %6" PRIu64 "K  ", "",
+                                            total_pss / 1024, total_uss / 1024);
+    } else {
+        ss << ::android::base::StringPrintf("%8s  %7s  %6" PRIu64 "K  %6" PRIu64 "K  ", "", "",
+                                            total_pss / 1024, total_uss / 1024);
+        if (has_swap) {
+            ss << ::android::base::StringPrintf("%6" PRIu64 "K  ", total_swap / 1024);
+            ss << ::android::base::StringPrintf("%6" PRIu64 "K  ", total_pswap / 1024);
+            ss << ::android::base::StringPrintf("%6" PRIu64 "K  ", total_uswap / 1024);
+            if (has_zram) {
+                ss << ::android::base::StringPrintf("%6" PRIu64 "K  ", total_zswap / 1024);
+            }
+        }
+    }
+    ss << "TOTAL";
+}
+
+static void print_sysmeminfo(std::stringstream& ss, ::android::meminfo::SysMemInfo& smi) {
+    if (has_swap) {
+        ss << ::android::base::StringPrintf("ZRAM: %" PRIu64 "K physical used for %" PRIu64
+                                            "K in swap "
+                                            "(%" PRIu64 "K total swap)",
+                                            smi.mem_zram_kb(),
+                                            (smi.mem_swap_kb() - smi.mem_swap_free_kb()),
+                                            smi.mem_swap_kb())
+           << std::endl;
+    }
+
+    ss << ::android::base::StringPrintf(" RAM: %" PRIu64 "K total, %" PRIu64 "K free, %" PRIu64
+                                        "K buffers, "
+                                        "%" PRIu64 "K cached, %" PRIu64 "K shmem, %" PRIu64
+                                        "K slab",
+                                        smi.mem_total_kb(), smi.mem_free_kb(), smi.mem_buffers_kb(),
+                                        smi.mem_cached_kb(), smi.mem_shmem_kb(), smi.mem_slab_kb());
+}
+
+int main(int argc, char* argv[]) {
+    auto pss_sort = [](ProcessRecord& a, ProcessRecord& b) {
+        MemUsage stats_a = show_wss ? a.Wss() : a.Usage();
+        MemUsage stats_b = show_wss ? b.Wss() : b.Usage();
+        return reverse_sort ? stats_a.pss < stats_b.pss : stats_a.pss > stats_b.pss;
+    };
+
+    auto uss_sort = [](ProcessRecord& a, ProcessRecord& b) {
+        MemUsage stats_a = show_wss ? a.Wss() : a.Usage();
+        MemUsage stats_b = show_wss ? b.Wss() : b.Usage();
+        return reverse_sort ? stats_a.uss < stats_b.uss : stats_a.uss > stats_b.uss;
+    };
+
+    auto rss_sort = [](ProcessRecord& a, ProcessRecord& b) {
+        MemUsage stats_a = show_wss ? a.Wss() : a.Usage();
+        MemUsage stats_b = show_wss ? b.Wss() : b.Usage();
+        return reverse_sort ? stats_a.rss < stats_b.pss : stats_a.pss > stats_b.pss;
+    };
+
+    auto vss_sort = [](ProcessRecord& a, ProcessRecord& b) {
+        MemUsage stats_a = show_wss ? a.Wss() : a.Usage();
+        MemUsage stats_b = show_wss ? b.Wss() : b.Usage();
+        return reverse_sort ? stats_a.vss < stats_b.vss : stats_a.vss > stats_b.vss;
+    };
+
+    auto swap_sort = [](ProcessRecord& a, ProcessRecord& b) {
+        MemUsage stats_a = show_wss ? a.Wss() : a.Usage();
+        MemUsage stats_b = show_wss ? b.Wss() : b.Usage();
+        return reverse_sort ? stats_a.swap < stats_b.swap : stats_a.swap > stats_b.swap;
+    };
+
+    auto oomadj_sort = [](ProcessRecord& a, ProcessRecord& b) {
+        return reverse_sort ? a.oomadj() < b.oomadj() : a.oomadj() > b.oomadj();
+    };
+
+    // default PSS sort
+    std::function<bool(ProcessRecord & a, ProcessRecord & b)> proc_sort = pss_sort;
+
+    // count all pages by default
+    uint64_t pgflags = 0;
+    uint64_t pgflags_mask = 0;
+
+    int opt;
+    while ((opt = getopt(argc, argv, "cChkoprRsuvwW")) != -1) {
+        switch (opt) {
+            case 'c':
+                pgflags = 0;
+                pgflags_mask = (1 << KPF_SWAPBACKED);
+                break;
+            case 'C':
+                pgflags = (1 << KPF_SWAPBACKED);
+                pgflags_mask = (1 << KPF_SWAPBACKED);
+                break;
+            case 'h':
+                usage(argv[0]);
+                return 0;
+                break;
+            case 'k':
+                pgflags = (1 << KPF_KSM);
+                pgflags_mask = (1 << KPF_KSM);
+                break;
+            case 'o':
+                proc_sort = oomadj_sort;
+                show_oomadj = true;
+                break;
+            case 'p':
+                proc_sort = pss_sort;
+                break;
+            case 'r':
+                proc_sort = rss_sort;
+                break;
+            case 'R':
+                reverse_sort = true;
+                break;
+            case 's':
+                proc_sort = swap_sort;
+                break;
+            case 'u':
+                proc_sort = uss_sort;
+                break;
+            case 'v':
+                proc_sort = vss_sort;
+                break;
+            case 'w':
+                show_wss = true;
+                break;
+            case 'W':
+                reset_wss = true;
+                break;
+            default:
+                abort();
+        }
+    }
+
+    std::vector<pid_t> pids;
+    std::vector<ProcessRecord> procs;
+    if (reset_wss) {
+        if (!read_all_pids(&pids,
+                           [&](pid_t pid) -> bool { return ProcMemInfo::ResetWorkingSet(pid); })) {
+            std::cerr << "Failed to reset working set of all processes" << std::endl;
+            exit(EXIT_FAILURE);
+        }
+        // we are done, all other options passed to procrank are ignored in the presence of '-W'
+        return 0;
+    }
+
+    ::android::meminfo::SysMemInfo smi;
+    if (!smi.ReadMemInfo()) {
+        std::cerr << "Failed to get system memory info" << std::endl;
+        exit(EXIT_FAILURE);
+    }
+
+    // Figure out swap and zram
+    uint64_t swap_total = smi.mem_swap_kb() * 1024;
+    has_swap = swap_total > 0;
+    // Allocate the swap array
+    auto swap_offset_array = std::make_unique<uint16_t[]>(swap_total / getpagesize());
+    if (has_swap) {
+        has_zram = smi.mem_zram_kb() > 0;
+        if (has_zram) {
+            zram_compression_ratio = static_cast<float>(smi.mem_zram_kb()) /
+                                     (smi.mem_swap_kb() - smi.mem_swap_free_kb());
+        }
+    }
+
+    auto mark_swap_usage = [&](pid_t pid) -> bool {
+        ProcessRecord proc(pid, show_wss, pgflags, pgflags_mask);
+        if (!proc.valid()) {
+            std::cerr << "Failed to create process record for: " << pid << std::endl;
+            return false;
+        }
+
+        // Skip processes with no memory mappings
+        uint64_t vss = show_wss ? proc.Wss().vss : proc.Usage().vss;
+        if (vss == 0) return true;
+
+        // collect swap_offset counts from all processes in 1st pass
+        if (!show_wss && has_swap &&
+            !count_swap_offsets(proc, swap_offset_array.get(), swap_total / getpagesize())) {
+            std::cerr << "Failed to count swap offsets for process: " << pid << std::endl;
+            return false;
+        }
+
+        procs.push_back(std::move(proc));
+        return true;
+    };
+
+    // Get a list of all pids currently running in the system in
+    // 1st pass through all processes. Mark each swap offset used by the process as we find them
+    // for calculating proportional swap usage later.
+    if (!read_all_pids(&pids, mark_swap_usage)) {
+        std::cerr << "Failed to read all pids from the system" << std::endl;
+        exit(EXIT_FAILURE);
+    }
+
+    std::stringstream ss;
+    if (procs.empty()) {
+        // This would happen in corner cases where procrank is being run to find KSM usage on a
+        // system with no KSM and combined with working set determination as follows
+        //   procrank -w -u -k
+        //   procrank -w -s -k
+        //   procrank -w -o -k
+        ss << "<empty>" << std::endl << std::endl;
+        print_sysmeminfo(ss, smi);
+        ss << std::endl;
+        std::cout << ss.str();
+        return 0;
+    }
+
+    // Sort all process records, default is PSS descending
+    std::sort(procs.begin(), procs.end(), proc_sort);
+
+    // start dumping output in string stream
+    print_header(ss);
+    ss << std::endl;
+
+    // 2nd pass to calculate and get per process stats to add them up
+    print_processes(ss, procs, swap_offset_array.get());
+
+    // Add separator to output
+    print_separator(ss);
+    ss << std::endl;
+
+    // Add totals to output
+    print_totals(ss);
+    ss << std::endl << std::endl;
+
+    // Add system information at the end
+    print_sysmeminfo(ss, smi);
+    ss << std::endl;
+
+    // dump on the screen
+    std::cout << ss.str();
+
+    return 0;
+}