tools/rtla: Add common_usage()

The rtla tools have significant code quadruplication in their usage
functions. Each tool implements its own version of the same help text
formatting and option descriptions, leading to maintenance overhead and
inconsistencies.  Documentation/tools/rtla/common_options.rst lists 14
common options.

Add common_usage() infrastructure to consolidate help formatting.
Subsequent patches will extend this to handle other common options.

The refactored output is almost identical to the original, with the
following changes:
- add square brackets to specify optionality: `usage: [rtla] ...`
- remove `-q` from timerlat hist because hist tools don't support it
- minor spacing

Signed-off-by: Costa Shulyupin <costa.shul@redhat.com>
Link: https://lore.kernel.org/r/20251124063204.845425-1-costa.shul@redhat.com
Signed-off-by: Tomas Glozar <tglozar@redhat.com>

diff --git a/tools/tracing/rtla/src/common.c b/tools/tracing/rtla/src/common.c
index 46e0263d6ae8e921ee63dafcbc4fa654fd6972ed..009a4bce97376132ff568edbaed2a6d17fdae8ef 100644 (file)
--- a/tools/tracing/rtla/src/common.c
+++ b/tools/tracing/rtla/src/common.c
@@ -4,6 +4,7 @@
 #include <pthread.h>
 #include <signal.h>
 #include <stdlib.h>
+#include <string.h>
 #include <unistd.h>
 #include "common.h"
 
@@ -368,3 +369,41 @@ int osn_set_stop(struct osnoise_tool *tool)
 
        return 0;
 }
+
+static void print_msg_array(const char * const *msgs)
+{
+       if (!msgs)
+               return;
+
+       for (int i = 0; msgs[i]; i++)
+               fprintf(stderr, "%s\n", msgs[i]);
+}
+
+/*
+ * common_usage - print complete usage information
+ */
+void common_usage(const char *tool, const char *mode,
+                 const char *desc, const char * const *start_msgs, const char * const *opt_msgs)
+{
+       static const char * const common_options[] = {
+               "         -h/--help: print this menu",
+               NULL
+       };
+       fprintf(stderr, "rtla %s", tool);
+       if (strcmp(mode, ""))
+               fprintf(stderr, " %s", mode);
+       fprintf(stderr, ": %s (version %s)\n\n", desc, VERSION);
+       fprintf(stderr, "  usage: [rtla] %s ", tool);
+
+       if (strcmp(mode, "top") == 0)
+               fprintf(stderr, "[top] [-h] ");
+       else
+               fprintf(stderr, "%s [-h] ", mode);
+
+       print_msg_array(start_msgs);
+       fprintf(stderr, "\n");
+       print_msg_array(common_options);
+       print_msg_array(opt_msgs);
+
+       exit(EXIT_SUCCESS);
+}

diff --git a/tools/tracing/rtla/src/common.h b/tools/tracing/rtla/src/common.h
index c5e73d4600a0989f4dd2db8831ee54b11e8e3c71..c48c9bfd20e3db4be8078d8e33cea3b60e907495 100644 (file)
--- a/tools/tracing/rtla/src/common.h
+++ b/tools/tracing/rtla/src/common.h
@@ -160,3 +160,6 @@ int common_apply_config(struct osnoise_tool *tool, struct common_params *params)
 int top_main_loop(struct osnoise_tool *tool);
 int hist_main_loop(struct osnoise_tool *tool);
 int osn_set_stop(struct osnoise_tool *tool);
+
+void common_usage(const char *tool, const char *mode,
+                 const char *desc, const char * const *start_msgs, const char * const *opt_msgs);

diff --git a/tools/tracing/rtla/src/osnoise_hist.c b/tools/tracing/rtla/src/osnoise_hist.c
index ff8c231e47c475f2475c89573a076806ce9b3882..372128db9e4af9030a974df9e7d38556c13e708b 100644 (file)
--- a/tools/tracing/rtla/src/osnoise_hist.c
+++ b/tools/tracing/rtla/src/osnoise_hist.c
@@ -409,16 +409,15 @@ osnoise_print_stats(struct osnoise_tool *tool)
  */
 static void osnoise_hist_usage(void)
 {
-       int i;
-
-       static const char * const msg[] = {
-               "",
-               "  usage: rtla osnoise hist [-h] [-D] [-d s] [-a us] [-p us] [-r us] [-s us] [-S us] \\",
+       static const char * const msg_start[] = {
+               "[-D] [-d s] [-a us] [-p us] [-r us] [-s us] [-S us] \\",
                "         [-T us] [-t [file]] [-e sys[:event]] [--filter <filter>] [--trigger <trigger>] \\",
                "         [-c cpu-list] [-H cpu-list] [-P priority] [-b N] [-E N] [--no-header] [--no-summary] \\",
                "         [--no-index] [--with-zeros] [-C [cgroup_name]] [--warm-up]",
-               "",
-               "         -h/--help: print this menu",
+               NULL,
+       };
+
+       static const char * const msg_opts[] = {
                "         -a/--auto: set automatic trace mode, stopping the session if argument in us sample is hit",
                "         -p/--period us: osnoise period in us",
                "         -r/--runtime us: osnoise runtime in us",
@@ -453,13 +452,8 @@ static void osnoise_hist_usage(void)
                NULL,
        };
 
-       fprintf(stderr, "rtla osnoise hist: a per-cpu histogram of the OS noise (version %s)\n",
-                       VERSION);
-
-       for (i = 0; msg[i]; i++)
-               fprintf(stderr, "%s\n", msg[i]);
-
-       exit(EXIT_SUCCESS);
+       common_usage("osnoise", "hist", "a per-cpu histogram of the OS noise",
+                    msg_start, msg_opts);
 }
 
 /*

diff --git a/tools/tracing/rtla/src/osnoise_top.c b/tools/tracing/rtla/src/osnoise_top.c
index 04c699bdd73638bf479c4319bb4ab6404e4c2900..1db1d946b6005d355ec4696a3bb1ec271220730e 100644 (file)
--- a/tools/tracing/rtla/src/osnoise_top.c
+++ b/tools/tracing/rtla/src/osnoise_top.c
@@ -257,14 +257,16 @@ osnoise_print_stats(struct osnoise_tool *top)
  */
 static void osnoise_top_usage(struct osnoise_params *params)
 {
-       int i;
+       const char *tool, *mode, *desc;
 
-       static const char * const msg[] = {
-               " [-h] [-q] [-D] [-d s] [-a us] [-p us] [-r us] [-s us] [-S us] \\",
+       static const char * const msg_start[] = {
+               "[-q] [-D] [-d s] [-a us] [-p us] [-r us] [-s us] [-S us] \\",
                "         [-T us] [-t [file]] [-e sys[:event]] [--filter <filter>] [--trigger <trigger>] \\",
                "         [-c cpu-list] [-H cpu-list] [-P priority] [-C [cgroup_name]] [--warm-up s]",
-               "",
-               "         -h/--help: print this menu",
+               NULL,
+       };
+
+       static const char * const msg_opts[] = {
                "         -a/--auto: set automatic trace mode, stopping the session if argument in us sample is hit",
                "         -p/--period us: osnoise period in us",
                "         -r/--runtime us: osnoise runtime in us",
@@ -295,25 +297,16 @@ static void osnoise_top_usage(struct osnoise_params *params)
        };
 
        if (params->mode == MODE_OSNOISE) {
-               fprintf(stderr,
-                       "rtla osnoise top: a per-cpu summary of the OS noise (version %s)\n",
-                       VERSION);
-
-               fprintf(stderr, "  usage: rtla osnoise [top]");
+               tool = "osnoise";
+               mode = "top";
+               desc = "a per-cpu summary of the OS noise";
+       } else {
+               tool = "hwnoise";
+               mode = "";
+               desc = "a summary of hardware-related noise";
        }
 
-       if (params->mode == MODE_HWNOISE) {
-               fprintf(stderr,
-                       "rtla hwnoise: a summary of hardware-related noise (version %s)\n",
-                       VERSION);
-
-               fprintf(stderr, "  usage: rtla hwnoise");
-       }
-
-       for (i = 0; msg[i]; i++)
-               fprintf(stderr, "%s\n", msg[i]);
-
-       exit(EXIT_SUCCESS);
+       common_usage(tool, mode, desc, msg_start, msg_opts);
 }
 
 /*

diff --git a/tools/tracing/rtla/src/timerlat_hist.c b/tools/tracing/rtla/src/timerlat_hist.c
index 1fb471a787b791e10647c50d39b185c0a00c1c12..2a5c543217baead967012b94895be661d53b81b8 100644 (file)
--- a/tools/tracing/rtla/src/timerlat_hist.c
+++ b/tools/tracing/rtla/src/timerlat_hist.c
@@ -696,17 +696,16 @@ timerlat_print_stats(struct osnoise_tool *tool)
  */
 static void timerlat_hist_usage(void)
 {
-       int i;
-
-       char *msg[] = {
-               "",
-               "  usage: [rtla] timerlat hist [-h] [-q] [-d s] [-D] [-n] [-a us] [-p us] [-i us] [-T us] [-s us] \\",
+       static const char * const msg_start[] = {
+               "[-d s] [-D] [-n] [-a us] [-p us] [-i us] [-T us] [-s us] \\",
                "         [-t [file]] [-e sys[:event]] [--filter <filter>] [--trigger <trigger>] [-c cpu-list] [-H cpu-list]\\",
                "         [-P priority] [-E N] [-b N] [--no-irq] [--no-thread] [--no-header] [--no-summary] \\",
                "         [--no-index] [--with-zeros] [--dma-latency us] [-C [cgroup_name]] [--no-aa] [--dump-task] [-u|-k]",
                "         [--warm-up s] [--deepest-idle-state n]",
-               "",
-               "         -h/--help: print this menu",
+               NULL,
+       };
+
+       static const char * const msg_opts[] = {
                "         -a/--auto: set automatic trace mode, stopping the session if argument in us latency is hit",
                "         -p/--period us: timerlat period in us",
                "         -i/--irq us: stop trace if the irq latency is higher than the argument in us",
@@ -750,13 +749,8 @@ static void timerlat_hist_usage(void)
                NULL,
        };
 
-       fprintf(stderr, "rtla timerlat hist: a per-cpu histogram of the timer latency (version %s)\n",
-                       VERSION);
-
-       for (i = 0; msg[i]; i++)
-               fprintf(stderr, "%s\n", msg[i]);
-
-       exit(EXIT_SUCCESS);
+       common_usage("timerlat", "hist", "a per-cpu histogram of the timer latency",
+                    msg_start, msg_opts);
 }
 
 /*

diff --git a/tools/tracing/rtla/src/timerlat_top.c b/tools/tracing/rtla/src/timerlat_top.c
index 29c2c1f717ed792122d5854556c7230aa97d412a..9ed8b931552fd79133a5724bedbffc658f5d34eb 100644 (file)
--- a/tools/tracing/rtla/src/timerlat_top.c
+++ b/tools/tracing/rtla/src/timerlat_top.c
@@ -476,15 +476,14 @@ timerlat_print_stats(struct osnoise_tool *top)
  */
 static void timerlat_top_usage(void)
 {
-       int i;
-
-       static const char *const msg[] = {
-               "",
-               "  usage: rtla timerlat [top] [-h] [-q] [-a us] [-d s] [-D] [-n] [-p us] [-i us] [-T us] [-s us] \\",
+       static const char *const msg_start[] = {
+               "[-q] [-a us] [-d s] [-D] [-n] [-p us] [-i us] [-T us] [-s us] \\",
                "         [[-t [file]] [-e sys[:event]] [--filter <filter>] [--trigger <trigger>] [-c cpu-list] [-H cpu-list]\\",
                "         [-P priority] [--dma-latency us] [--aa-only us] [-C [cgroup_name]] [-u|-k] [--warm-up s] [--deepest-idle-state n]",
-               "",
-               "         -h/--help: print this menu",
+               NULL,
+       };
+
+       static const char *const msg_opts[] = {
                "         -a/--auto: set automatic trace mode, stopping the session if argument in us latency is hit",
                "            --aa-only us: stop if <us> latency is hit, only printing the auto analysis (reduces CPU usage)",
                "         -p/--period us: timerlat period in us",
@@ -522,13 +521,8 @@ static void timerlat_top_usage(void)
                NULL,
        };
 
-       fprintf(stderr, "rtla timerlat top: a per-cpu summary of the timer latency (version %s)\n",
-                       VERSION);
-
-       for (i = 0; msg[i]; i++)
-               fprintf(stderr, "%s\n", msg[i]);
-
-       exit(EXIT_SUCCESS);
+       common_usage("timerlat", "top", "a per-cpu summary of the timer latency",
+                    msg_start, msg_opts);
 }
 
 /*