From b608ddda22ac33195ba57311d42ac83facbd8695 Mon Sep 17 00:00:00 2001

From: Michal Schmidt <mschmidt@redhat.com>

Date: Thu, 16 Feb 2012 00:04:00 +0100

Subject: [PATCH 2/2] better error message

Only suggest CONFIG_LATENCYTOP on ENOENT.

Print the message after curses is cleaned up to make it visible.

---

 src/latencytop.c |   18 +++++++++++++++---

 1 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/src/latencytop.c b/src/latencytop.c

index 0ffb7f3..3b62c5d 100644

--- a/src/latencytop.c

+++ b/src/latencytop.c

@@ -24,6 +24,7 @@

 #define _GNU_SOURCE

+#include <errno.h>

 #include <stdio.h>

 #include <stdlib.h>

 #include <unistd.h>

@@ -113,6 +114,17 @@ static void fixup_reason(struct latency_line *line, char *c)

 		strncpy(line->reason, c2, 1024);

 }

+static int die_errno;

+

+static void print_error_msg(void) {

+	if (!die_errno)

+		return;

+

+	fprintf(stderr, "Failed to open /proc/latency_stats: %s\n", strerror(die_errno));

+	if (die_errno == ENOENT)

+		fprintf(stderr, "Please enable the CONFIG_LATENCYTOP configuration in your kernel.\n");

+}

+

 void parse_global_list(void)

 {

 	FILE *file;

@@ -120,8 +132,7 @@ void parse_global_list(void)

 	size_t dummy;

 	file = fopen("/proc/latency_stats","r+");

 	if (!file) {

-		fprintf(stderr, "Please enable the CONFIG_LATENCYTOP configuration in your kernel.\n");

-		fprintf(stderr, "Exiting...\n");

+		die_errno = errno;

 		exit(EXIT_FAILURE);

 	}

 	/* wipe first line */

@@ -540,7 +551,8 @@ int main(int argc, char **argv)

 	enable_sysctl();

 	atexit(cleanup_sysctl);

-

+	/* needs to run after curses is gone */

+	atexit(print_error_msg);

 #ifdef HAS_GTK_GUI

 	if (preinitialize_gtk_ui(&argc, &argv))

 		use_gtk = 1;

-- 

1.7.7.6