[v8,4/5] eal: add option to put timestamp on console output

diff --git a/app/test/test_eal_flags.c b/app/test/test_eal_flags.c
index 6cb4b0675730..07a038fb6051 100644
--- a/app/test/test_eal_flags.c
+++ b/app/test/test_eal_flags.c
@@ -1055,6 +1055,10 @@  test_misc_flags(void)
 	const char * const argv22[] = {prgname, prefix, mp_flag,
 				       "--huge-worker-stack=512"};
 
+	/* Try running with --log-timestamp */
+	const char * const argv23[] = {prgname, prefix, mp_flag,
+				       "--log-timestamp" };
+
 	/* run all tests also applicable to FreeBSD first */
 
 	if (launch_proc(argv0) == 0) {
@@ -1162,6 +1166,11 @@  test_misc_flags(void)
 		printf("Error - process did not run ok with --huge-worker-stack=size parameter\n");
 		goto fail;
 	}
+	if (launch_proc(argv23) != 0) {
+		printf("Error - process did not run ok with --log-timestamp parameter\n");
+		goto fail;
+	}
+
 
 	rmdir(hugepath_dir3);
 	rmdir(hugepath_dir2);
diff --git a/doc/guides/prog_guide/log_lib.rst b/doc/guides/prog_guide/log_lib.rst
index aacb36c36ce0..1d6b2e3cea5d 100644
--- a/doc/guides/prog_guide/log_lib.rst
+++ b/doc/guides/prog_guide/log_lib.rst
@@ -73,6 +73,16 @@  For example::
 	/path/to/app --syslog local0
 
 
+Console timestamp
+~~~~~~~~~~~~~~~~~
+
+On Linux and FreeBSD, an optional timestamp can be added before each
+message by adding the ``--log-timestamp`` option.
+For example::
+
+	/path/to/app --log-level=lib.*:debug --log-timestamp
+
+
 Using Logging APIs to Generate Log Messages
 -------------------------------------------
 
diff --git a/lib/eal/common/eal_common_options.c b/lib/eal/common/eal_common_options.c
index 7310d10dfd78..9bc95433d27c 100644
--- a/lib/eal/common/eal_common_options.c
+++ b/lib/eal/common/eal_common_options.c
@@ -77,6 +77,7 @@  eal_long_options[] = {
 	{OPT_IOVA_MODE,	        1, NULL, OPT_IOVA_MODE_NUM        },
 	{OPT_LCORES,            1, NULL, OPT_LCORES_NUM           },
 	{OPT_LOG_LEVEL,         1, NULL, OPT_LOG_LEVEL_NUM        },
+	{OPT_LOG_TIMESTAMP,     0, NULL, OPT_LOG_TIMESTAMP_NUM    },
 	{OPT_TRACE,             1, NULL, OPT_TRACE_NUM            },
 	{OPT_TRACE_DIR,         1, NULL, OPT_TRACE_DIR_NUM        },
 	{OPT_TRACE_BUF_SIZE,    1, NULL, OPT_TRACE_BUF_SIZE_NUM   },
@@ -1663,6 +1664,7 @@  eal_log_level_parse(int argc, char * const argv[])
 
 		switch (opt) {
 		case OPT_LOG_LEVEL_NUM:
+		case OPT_LOG_TIMESTAMP_NUM:
 			if (eal_parse_common_option(opt, optarg, internal_conf) < 0)
 				return -1;
 			break;
@@ -1890,7 +1892,7 @@  eal_parse_common_option(int opt, const char *optarg,
 		break;
 #endif
 
-	case OPT_LOG_LEVEL_NUM: {
+	case OPT_LOG_LEVEL_NUM:
 		if (eal_parse_log_level(optarg) < 0) {
 			EAL_LOG(ERR,
 				"invalid parameters for --"
@@ -1898,7 +1900,10 @@  eal_parse_common_option(int opt, const char *optarg,
 			return -1;
 		}
 		break;
-	}
+
+	case OPT_LOG_TIMESTAMP_NUM:
+		eal_log_enable_timestamp();
+		break;
 
 #ifndef RTE_EXEC_ENV_WINDOWS
 	case OPT_TRACE_NUM: {
@@ -2261,6 +2266,7 @@  eal_common_usage(void)
 	       "  --"OPT_PROC_TYPE"         Type of this process (primary|secondary|auto)\n"
 #ifndef RTE_EXEC_ENV_WINDOWS
 	       "  --"OPT_SYSLOG"            Set syslog facility\n"
+	       "  --"OPT_LOG_TIMESTAMP"     Timestamp log output\n"
 #endif
 	       "  --"OPT_LOG_LEVEL"=<level> Set global log level\n"
 	       "  --"OPT_LOG_LEVEL"=<type-match>:<level>\n"
diff --git a/lib/eal/common/eal_options.h b/lib/eal/common/eal_options.h
index f3f2e104f6d7..e24c9eca53ca 100644
--- a/lib/eal/common/eal_options.h
+++ b/lib/eal/common/eal_options.h
@@ -35,6 +35,8 @@  enum {
 	OPT_LCORES_NUM,
 #define OPT_LOG_LEVEL         "log-level"
 	OPT_LOG_LEVEL_NUM,
+#define OPT_LOG_TIMESTAMP     "log-timestamp"
+	OPT_LOG_TIMESTAMP_NUM,
 #define OPT_TRACE             "trace"
 	OPT_TRACE_NUM,
 #define OPT_TRACE_DIR         "trace-dir"
diff --git a/lib/log/log_internal.h b/lib/log/log_internal.h
index c77e687e28bc..1af27fe8f9d3 100644
--- a/lib/log/log_internal.h
+++ b/lib/log/log_internal.h
@@ -5,8 +5,10 @@ 
 #ifndef LOG_INTERNAL_H
 #define LOG_INTERNAL_H
 
+#include <stdbool.h>
 #include <stdio.h>
 #include <stdint.h>
+#include <time.h>
 
 #include <rte_compat.h>
 
@@ -44,4 +46,11 @@  const char *eal_log_level2str(uint32_t level);
 __rte_internal
 void rte_eal_log_cleanup(void);
 
+/*
+ * Add timestamp to console logs
+ */
+__rte_internal
+void eal_log_enable_timestamp(void);
+
+
 #endif /* LOG_INTERNAL_H */
diff --git a/lib/log/log_unix.c b/lib/log/log_unix.c
index a415bae5774d..71ce366b6825 100644
--- a/lib/log/log_unix.c
+++ b/lib/log/log_unix.c
@@ -2,24 +2,52 @@ 
  * Copyright(c) 2010-2014 Intel Corporation
  */
 
+#include <stdbool.h>
 #include <stdio.h>
 #include <sys/types.h>
+#include <sys/uio.h>
 #include <syslog.h>
+#include <time.h>
+#include <unistd.h>
 
 #include <rte_log.h>
 
 #include "log_internal.h"
 
+static bool timestamp_enabled;
+static struct timespec log_started;
+
+void
+eal_log_enable_timestamp(void)
+{
+	timestamp_enabled = true;
+	clock_gettime(CLOCK_MONOTONIC, &log_started);
+}
+
 /*
  * default log function
  */
 static ssize_t
 console_log_write(__rte_unused void *c, const char *buf, size_t size)
 {
+	struct timespec ts;
 	ssize_t ret;
 
-	/* write on stderr */
-	ret = fwrite(buf, 1, size, stderr);
+	if (timestamp_enabled) {
+		clock_gettime(CLOCK_MONOTONIC, &ts);
+		ts.tv_sec -= log_started.tv_sec;
+		ts.tv_nsec -= log_started.tv_nsec;
+		if (ts.tv_nsec < 0) {
+			--ts.tv_sec;
+			ts.tv_nsec += 1000000000ul;
+		}
+
+		ret = fprintf(stderr, "[%8lu.%06lu] %.*s",
+			      ts.tv_sec, ts.tv_nsec / 1000u,
+			      (int) size, buf);
+	} else {
+		ret = fwrite(buf, 1, size, stderr);
+	}
 	fflush(stderr);
 
 	/* Syslog error levels are from 0 to 7, so subtract 1 to convert */
diff --git a/lib/log/log_windows.c b/lib/log/log_windows.c
index a6a08895501e..0c471bfb15f6 100644
--- a/lib/log/log_windows.c
+++ b/lib/log/log_windows.c
@@ -6,6 +6,12 @@ 
 #include <rte_log.h>
 #include "log_internal.h"
 
+void
+eal_log_enable_timestamp(void)
+{
+	/* not implemented */
+}
+
 /* set the log to default function, called during eal init process. */
 int
 eal_log_init(__rte_unused const char *id, __rte_unused int facility)
diff --git a/lib/log/version.map b/lib/log/version.map
index 6ecc656d1d65..32c555f29e79 100644
--- a/lib/log/version.map
+++ b/lib/log/version.map
@@ -25,6 +25,7 @@  DPDK_24 {
 INTERNAL {
 	global:
 
+	eal_log_enable_timestamp;
 	eal_log_get_default;
 	eal_log_init;
 	eal_log_level2str;