Attachment 149299 Details for Bug 226997 – Patch sent to linux-hotplug-devel@lists.sourceforge.net

[patch] Patch sent to linux-hotplug-devel@lists.sourceforge.net

udev.patch (text/plain), 1.94 KB, created by George Beshers on 2007-03-05 22:27:26 UTC

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Creator: George Beshers

Created: 2007-03-05 22:27:26 UTC

Size: 1.94 KB

patch

obsolete

>This came up on a system with 1024cores (well 768cpus and 256
>hyper-threads) where the buffer size for reading /proc/stat was
>not large enough causing udev to fail during the boot process.
>The read_proc_stat(void) eliminates this problem.
>
>
>--- udev-105/udevd.c	2007-02-02 19:24:48.000000000 -0500
>+++ udev-105.new/udevd.c	2007-02-19 13:47:54.000000000 -0500
>@@ -357,25 +357,58 @@
> 	return memsize / 1024;
> }
> 
>-static int cpu_count(void)
>+/*
>+ * Use the same buffer for cpu_count() and running_processes()
>+ */
>+
>+static char* stat_buf = NULL;
>+static int   stat_buf_size = 4096;
>+
>+static int read_proc_stat(void)
> {
> 	int f;
>-	char buf[32768];
> 	int len;
>-	const char *pos;
>-	int count = 0;
> 
>-	f = open("/proc/stat", O_RDONLY);
>-	if (f == -1)
>-		return -1;
>+	if (stat_buf == NULL) {
>+		stat_buf = malloc(stat_buf_size);
>+		if (stat_buf == NULL)
>+			return -1;
>+	}
> 
>-	len = read(f, buf, sizeof(buf)-1);
>+	do {
>+		f = open("/proc/stat", O_RDONLY);
>+		if (f == -1)
>+			return -1;
>+
>+		len = read(f, stat_buf, stat_buf_size-1);
>+		if (len < stat_buf_size-1)
>+			break;
>+
>+		stat_buf_size *= 2;
>+		stat_buf = realloc(stat_buf, stat_buf_size);
>+		if (stat_buf == NULL)
>+			return -1;
>+	} while (1);
> 	close(f);
>+
> 	if (len <= 0)
> 		return -1;
>-	buf[len] = '\0';
>+	stat_buf[len] = '\0';
>+	return len;
>+}
>+
> 
>-	pos = strstr(buf, "cpu");
>+static int cpu_count(void)
>+{
>+	int len;
>+	const char *pos;
>+	int count = 0;
>+
>+	len = read_proc_stat();
>+	if (len <= 0)
>+		return -1;
>+
>+	pos = strstr(stat_buf, "cpu");
> 	if (pos == NULL)
> 		return -1;
> 
>@@ -392,23 +425,15 @@
> 
> static int running_processes(void)
> {
>-	int f;
>-	char buf[32768];
> 	int len;
> 	int running;
> 	const char *pos;
> 
>-	f = open("/proc/stat", O_RDONLY);
>-	if (f == -1)
>-		return -1;
>-
>-	len = read(f, buf, sizeof(buf)-1);
>-	close(f);
>+	len = read_proc_stat();
> 	if (len <= 0)
> 		return -1;
>-	buf[len] = '\0';
> 
>-	pos = strstr(buf, "procs_running ");
>+	pos = strstr(stat_buf, "procs_running ");
> 	if (pos == NULL)
> 		return -1;
>

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Attachments on bug 226997: 149299 | 153906 | 154301 | 156355