diff --git a/logcat/logcat.cpp b/logcat/logcat.cpp
index 6b85f4b..831b4e3 100644
--- a/logcat/logcat.cpp
+++ b/logcat/logcat.cpp
@@ -17,6 +17,7 @@
 #include <ctype.h>
 #include <dirent.h>
 #include <errno.h>
+#include <error.h>
 #include <fcntl.h>
 #include <getopt.h>
 #include <math.h>
@@ -108,10 +109,6 @@
 
 enum helpType { HELP_FALSE, HELP_TRUE, HELP_FORMAT };
 
-// if show_help is set, newline required in fmt statement to transition to usage
-static void LogcatPanic(enum helpType showHelp, const char* fmt, ...) __printflike(2, 3)
-        __attribute__((__noreturn__));
-
 #ifndef F2FS_IOC_SET_PIN_FILE
 #define F2FS_IOCTL_MAGIC       0xf5
 #define F2FS_IOC_SET_PIN_FILE _IOW(F2FS_IOCTL_MAGIC, 13, __u32)
@@ -170,7 +167,7 @@
     output_fd_.reset(openLogFile(output_file_name_, log_rotate_size_kb_));
 
     if (!output_fd_.ok()) {
-        LogcatPanic(HELP_FALSE, "couldn't open output file");
+        error(EXIT_FAILURE, errno, "Couldn't open output file");
     }
 
     out_byte_count_ = 0;
@@ -209,7 +206,7 @@
             bytesWritten = android_log_printLogLine(logformat_.get(), output_fd_.get(), &entry);
 
             if (bytesWritten < 0) {
-                LogcatPanic(HELP_FALSE, "output error");
+                error(EXIT_FAILURE, 0, "Output error.");
             }
         }
     }
@@ -229,7 +226,7 @@
         if (dprintf(output_fd_.get(), "--------- %s %s\n",
                     printed_start_[log_id] ? "switch to" : "beginning of",
                     android_log_id_to_name(log_id)) < 0) {
-            LogcatPanic(HELP_FALSE, "output error");
+            error(EXIT_FAILURE, errno, "Output error");
         }
     }
     last_printed_id_ = log_id;
@@ -259,18 +256,16 @@
     output_fd_.reset(openLogFile(output_file_name_, log_rotate_size_kb_));
 
     if (!output_fd_.ok()) {
-        LogcatPanic(HELP_FALSE, "couldn't open output file");
+        error(EXIT_FAILURE, errno, "Couldn't open output file");
     }
 
     struct stat statbuf;
     if (fstat(output_fd_.get(), &statbuf) == -1) {
-        output_fd_.reset();
-        LogcatPanic(HELP_FALSE, "couldn't get output file stat\n");
+        error(EXIT_FAILURE, errno, "Couldn't get output file stat");
     }
 
     if ((size_t)statbuf.st_size > SIZE_MAX || statbuf.st_size < 0) {
-        output_fd_.reset();
-        LogcatPanic(HELP_FALSE, "invalid output file stat\n");
+        error(EXIT_FAILURE, 0, "Invalid output file stat.");
     }
 
     out_byte_count_ = statbuf.st_size;
@@ -427,27 +422,6 @@
     return std::make_pair(value, multipliers[i]);
 }
 
-static void LogcatPanic(enum helpType showHelp, const char* fmt, ...) {
-    va_list args;
-    va_start(args, fmt);
-    vfprintf(stderr, fmt, args);
-    va_end(args);
-
-    switch (showHelp) {
-        case HELP_TRUE:
-            show_help();
-            break;
-        case HELP_FORMAT:
-            show_format_help();
-            break;
-        case HELP_FALSE:
-        default:
-            break;
-    }
-
-    exit(EXIT_FAILURE);
-}
-
 static char* parseTime(log_time& t, const char* cp) {
     char* ep = t.strptime(cp, "%m-%d %H:%M:%S.%q");
     if (ep) return ep;
@@ -612,13 +586,12 @@
                 // only long options
                 if (long_options[option_index].name == pid_str) {
                     if (pid != 0) {
-                        LogcatPanic(HELP_TRUE, "Only supports one PID argument.\n");
+                        error(EXIT_FAILURE, 0, "Only one --pid argument can be provided.");
                     }
 
-                    // ToDo: determine runtime PID_MAX?
                     if (!ParseUint(optarg, &pid) || pid < 1) {
-                        LogcatPanic(HELP_TRUE, "%s %s out of range\n",
-                                    long_options[option_index].name, optarg);
+                        error(EXIT_FAILURE, 0, "%s %s out of range.",
+                              long_options[option_index].name, optarg);
                     }
                     break;
                 }
@@ -628,8 +601,8 @@
                     // ToDo: implement API that supports setting a wrap timeout
                     size_t dummy = ANDROID_LOG_WRAP_DEFAULT_TIMEOUT;
                     if (optarg && (!ParseUint(optarg, &dummy) || dummy < 1)) {
-                        LogcatPanic(HELP_TRUE, "%s %s out of range\n",
-                                    long_options[option_index].name, optarg);
+                        error(EXIT_FAILURE, 0, "%s %s out of range.",
+                              long_options[option_index].name, optarg);
                     }
                     if (dummy != ANDROID_LOG_WRAP_DEFAULT_TIMEOUT) {
                         fprintf(stderr, "WARNING: %s %u seconds, ignoring %zu\n",
@@ -678,13 +651,13 @@
                 if (strspn(optarg, "0123456789") != strlen(optarg)) {
                     char* cp = parseTime(tail_time, optarg);
                     if (!cp) {
-                        LogcatPanic(HELP_FALSE, "-%c \"%s\" not in time format\n", c, optarg);
+                        error(EXIT_FAILURE, 0, "-%c '%s' not in time format.", c, optarg);
                     }
                     if (*cp) {
                         char ch = *cp;
                         *cp = '\0';
-                        fprintf(stderr, "WARNING: -%c \"%s\"\"%c%s\" time truncated\n", c, optarg,
-                                ch, cp + 1);
+                        fprintf(stderr, "WARNING: -%c '%s' '%c%s' time truncated\n", c, optarg, ch,
+                                cp + 1);
                         *cp = ch;
                     }
                 } else {
@@ -705,8 +678,8 @@
 
             case 'm': {
                 if (!ParseUint(optarg, &max_count_) || max_count_ < 1) {
-                    LogcatPanic(HELP_FALSE, "-%c \"%s\" isn't an integer greater than zero\n", c,
-                                optarg);
+                    error(EXIT_FAILURE, 0, "-%c '%s' isn't an integer greater than zero.", c,
+                          optarg);
                 }
             } break;
 
@@ -719,7 +692,7 @@
 
             case 'G': {
                 if (!ParseByteCount(optarg, &setLogSize) || setLogSize < 1) {
-                    LogcatPanic(HELP_FALSE, "ERROR: -G <num><multiplier>\n");
+                    error(EXIT_FAILURE, 0, "-G must be specified as <num><multiplier>.");
                 }
             } break;
 
@@ -743,7 +716,8 @@
                     } else {
                         log_id_t log_id = android_name_to_log_id(buffer.c_str());
                         if (log_id >= LOG_ID_MAX) {
-                            LogcatPanic(HELP_TRUE, "unknown buffer %s\n", buffer.c_str());
+                            error(EXIT_FAILURE, 0, "Unknown buffer '%s' listed for -b.",
+                                  buffer.c_str());
                         }
                         if (log_id == LOG_ID_SECURITY) {
                             security_buffer_selected = true;
@@ -767,13 +741,13 @@
 
             case 'r':
                 if (!ParseUint(optarg, &log_rotate_size_kb_) || log_rotate_size_kb_ < 1) {
-                    LogcatPanic(HELP_TRUE, "Invalid parameter \"%s\" to -r\n", optarg);
+                    error(EXIT_FAILURE, 0, "Invalid parameter '%s' to -r.", optarg);
                 }
                 break;
 
             case 'n':
                 if (!ParseUint(optarg, &max_rotated_logs_) || max_rotated_logs_ < 1) {
-                    LogcatPanic(HELP_TRUE, "Invalid parameter \"%s\" to -n\n", optarg);
+                    error(EXIT_FAILURE, 0, "Invalid parameter '%s' to -n.", optarg);
                 }
                 break;
 
@@ -785,7 +759,7 @@
                 for (const auto& arg : Split(optarg, delimiters)) {
                     int err = SetLogFormat(arg.c_str());
                     if (err < 0) {
-                        LogcatPanic(HELP_FORMAT, "Invalid parameter \"%s\" to -v\n", arg.c_str());
+                        error(EXIT_FAILURE, 0, "Invalid parameter '%s' to -v.", arg.c_str());
                     }
                     if (err) hasSetLogFormat = true;
                 }
@@ -882,20 +856,25 @@
                 break;
 
             case ':':
-                LogcatPanic(HELP_TRUE, "Option -%c needs an argument\n", optopt);
+                error(EXIT_FAILURE, 0, "Option '%s' needs an argument.", argv[optind - 1]);
+                break;
 
             case 'h':
                 show_help();
                 show_format_help();
                 return EXIT_SUCCESS;
 
+            case '?':
+                error(EXIT_FAILURE, 0, "Unknown option '%s'.", argv[optind - 1]);
+                break;
+
             default:
-                LogcatPanic(HELP_TRUE, "Unrecognized Option %c\n", optopt);
+                error(EXIT_FAILURE, 0, "Unknown getopt_long() result '%c'.", c);
         }
     }
 
     if (max_count_ && got_t) {
-        LogcatPanic(HELP_TRUE, "Cannot use -m (--max-count) and -t together\n");
+        error(EXIT_FAILURE, 0, "Cannot use -m (--max-count) and -t together.");
     }
     if (print_it_anyways_ && (!regex_ || !max_count_)) {
         // One day it would be nice if --print -v color and --regex <expr>
@@ -915,12 +894,12 @@
     }
 
     if (log_rotate_size_kb_ != 0 && !output_file_name_) {
-        LogcatPanic(HELP_TRUE, "-r requires -f as well\n");
+        error(EXIT_FAILURE, 0, "-r requires -f as well.");
     }
 
     if (setId != 0) {
         if (!output_file_name_) {
-            LogcatPanic(HELP_TRUE, "--id='%s' requires -f as well\n", setId);
+            error(EXIT_FAILURE, 0, "--id='%s' requires -f as well.", setId);
         }
 
         std::string file_name = StringPrintf("%s.id", output_file_name_);
@@ -952,7 +931,7 @@
     if (forceFilters.size()) {
         int err = android_log_addFilterString(logformat_.get(), forceFilters.c_str());
         if (err < 0) {
-            LogcatPanic(HELP_FALSE, "Invalid filter expression in logcat args\n");
+            error(EXIT_FAILURE, 0, "Invalid filter expression in logcat args.");
         }
     } else if (argc == optind) {
         // Add from environment variable
@@ -962,7 +941,7 @@
             int err = android_log_addFilterString(logformat_.get(), env_tags_orig);
 
             if (err < 0) {
-                LogcatPanic(HELP_TRUE, "Invalid filter expression in ANDROID_LOG_TAGS\n");
+                error(EXIT_FAILURE, 0, "Invalid filter expression in ANDROID_LOG_TAGS.");
             }
         }
     } else {
@@ -970,17 +949,17 @@
         for (int i = optind ; i < argc ; i++) {
             int err = android_log_addFilterString(logformat_.get(), argv[i]);
             if (err < 0) {
-                LogcatPanic(HELP_TRUE, "Invalid filter expression '%s'\n", argv[i]);
+                error(EXIT_FAILURE, 0, "Invalid filter expression '%s'.", argv[i]);
             }
         }
     }
 
     if (mode & ANDROID_LOG_PSTORE) {
         if (output_file_name_) {
-            LogcatPanic(HELP_FALSE, "-c is ambiguous with both -f and -L specified.\n");
+            error(EXIT_FAILURE, 0, "-c is ambiguous with both -f and -L specified.");
         }
         if (setLogSize || getLogSize || printStatistics || getPruneList || setPruneList) {
-            LogcatPanic(HELP_TRUE, "-L is incompatible with -g/-G, -S, and -p/-P\n");
+            error(EXIT_FAILURE, 0, "-L is incompatible with -g/-G, -S, and -p/-P.");
         }
         if (clearLog) {
             unlink("/sys/fs/pstore/pmsg-ramoops-0");
@@ -990,7 +969,7 @@
 
     if (output_file_name_) {
         if (setLogSize || getLogSize || printStatistics || getPruneList || setPruneList) {
-            LogcatPanic(HELP_TRUE, "-f is incompatible with -g/-G, -S, and -p/-P\n");
+            error(EXIT_FAILURE, 0, "-f is incompatible with -g/-G, -S, and -p/-P.");
         }
 
         if (clearLog || setId) {
@@ -1078,21 +1057,20 @@
 
     // report any errors in the above loop and exit
     if (!open_device_failures.empty()) {
-        LogcatPanic(HELP_FALSE, "Unable to open log device%s '%s'\n",
-                    open_device_failures.size() > 1 ? "s" : "",
-                    Join(open_device_failures, ",").c_str());
+        error(EXIT_FAILURE, 0, "Unable to open log device%s '%s'.",
+              open_device_failures.size() > 1 ? "s" : "", Join(open_device_failures, ",").c_str());
     }
     if (!clear_failures.empty()) {
-        LogcatPanic(HELP_FALSE, "failed to clear the '%s' log%s\n",
-                    Join(clear_failures, ",").c_str(), clear_failures.size() > 1 ? "s" : "");
+        error(EXIT_FAILURE, 0, "failed to clear the '%s' log%s.", Join(clear_failures, ",").c_str(),
+              clear_failures.size() > 1 ? "s" : "");
     }
     if (!set_size_failures.empty()) {
-        LogcatPanic(HELP_FALSE, "failed to set the '%s' log size%s\n",
-                    Join(set_size_failures, ",").c_str(), set_size_failures.size() > 1 ? "s" : "");
+        error(EXIT_FAILURE, 0, "failed to set the '%s' log size%s.",
+              Join(set_size_failures, ",").c_str(), set_size_failures.size() > 1 ? "s" : "");
     }
     if (!get_size_failures.empty()) {
-        LogcatPanic(HELP_FALSE, "failed to get the readable '%s' log size%s\n",
-                    Join(get_size_failures, ",").c_str(), get_size_failures.size() > 1 ? "s" : "");
+        error(EXIT_FAILURE, 0, "failed to get the readable '%s' log size%s.",
+              Join(get_size_failures, ",").c_str(), get_size_failures.size() > 1 ? "s" : "");
     }
 
     if (setPruneList) {
@@ -1103,11 +1081,11 @@
         if (asprintf(&buf, "%-*s", (int)(bLen - 1), setPruneList) > 0) {
             buf[len] = '\0';
             if (android_logger_set_prune_list(logger_list.get(), buf, bLen)) {
-                LogcatPanic(HELP_FALSE, "failed to set the prune list");
+                error(EXIT_FAILURE, 0, "Failed to set the prune list.");
             }
             free(buf);
         } else {
-            LogcatPanic(HELP_FALSE, "failed to set the prune list (alloc)");
+            error(EXIT_FAILURE, 0, "Failed to set the prune list (alloc).");
         }
         return EXIT_SUCCESS;
     }
@@ -1138,7 +1116,7 @@
         }
 
         if (!buf) {
-            LogcatPanic(HELP_FALSE, "failed to read data");
+            error(EXIT_FAILURE, 0, "Failed to read data.");
         }
 
         // remove trailing FF
@@ -1168,30 +1146,29 @@
         struct log_msg log_msg;
         int ret = android_logger_list_read(logger_list.get(), &log_msg);
         if (!ret) {
-            LogcatPanic(HELP_FALSE, R"init(read: unexpected EOF!
+            error(EXIT_FAILURE, 0, R"init(Unexpected EOF!
 
 This means that either logd crashed, or more likely, this instance of logcat was unable to read log
 messages as quickly as they were being produced.
 
-If you have enabled significant logging, look into using the -G option to increase log buffer sizes.
-)init");
+If you have enabled significant logging, look into using the -G option to increase log buffer sizes.)init");
         }
 
         if (ret < 0) {
             if (ret == -EAGAIN) break;
 
             if (ret == -EIO) {
-                LogcatPanic(HELP_FALSE, "read: unexpected EOF!\n");
+                error(EXIT_FAILURE, 0, "Unexpected EOF!");
             }
             if (ret == -EINVAL) {
-                LogcatPanic(HELP_FALSE, "read: unexpected length.\n");
+                error(EXIT_FAILURE, 0, "Unexpected length.");
             }
-            LogcatPanic(HELP_FALSE, "logcat read failure\n");
+            error(EXIT_FAILURE, errno, "Logcat read failure");
         }
 
         if (log_msg.id() > LOG_ID_MAX) {
-            LogcatPanic(HELP_FALSE, "read: unexpected log id (%d) over LOG_ID_MAX (%d)",
-                        log_msg.id(), LOG_ID_MAX);
+            error(EXIT_FAILURE, 0, "Unexpected log id (%d) over LOG_ID_MAX (%d).", log_msg.id(),
+                  LOG_ID_MAX);
         }
 
         PrintDividers(log_msg.id(), printDividers);
diff --git a/rootdir/init.rc b/rootdir/init.rc
index ff68734..e2ecad4 100644
--- a/rootdir/init.rc
+++ b/rootdir/init.rc
@@ -770,6 +770,11 @@
     write /sys/fs/f2fs/${dev.mnt.blk.data}/cp_interval 200
     write /sys/fs/f2fs/${dev.mnt.blk.data}/gc_urgent_sleep_time 50
 
+    # limit discard size to 128MB in order to avoid long IO latency
+    # for filesystem tuning first (dm or sda)
+    # Note that, if dm-<num> is used, sda/mmcblk0 should be tuned in vendor/init.rc
+    write /sys/devices/virtual/block/${dev.mnt.blk.data}/queue/discard_max_bytes 134217728
+
     # Permissions for System Server and daemons.
     chown system system /sys/power/autosleep