[PATCH] libnuma: enumerate CPUs correctly

"Jan Beulich" <[email protected]>
Newsgroups org.kernel.vger.linux-numa
Message-ID <[email protected]>
Just matching the first three characters of the directory entries under
/sys/devices/system/cpu/ isn't sufficient, as that also include items
like "cpuidle" and "cpufreq".

Further, just counting entries isn't right, since there may be holes in
the numbering, but the code really is after obtaining the highest
possible CPU number.

Signed-off-by: Jan Beulich <[email protected]>
Cc: Thomas Renninger <[email protected]>

--- 2.0.4-rc2.orig/libnuma.c	2010-06-09 10:22:33.000000000 +0200
+++ 2.0.4-rc2/libnuma.c	2010-06-09 11:07:21.000000000 +0200
@@ -536,7 +536,6 @@ set_numa_max_cpu(void)
 static void
 set_configured_cpus(void)
 {
-	int		filecount=0;
 	char		*dirnamep = "/sys/devices/system/cpu";
 	struct dirent	*dirent;
 	DIR		*dir;
@@ -548,15 +547,19 @@ set_configured_cpus(void)
 		return;
 	}
 	while ((dirent = readdir(dir)) != 0) {
-		if (!strncmp("cpu", dirent->d_name, 3)) {
-			filecount++;
-		} else {
-			continue;
+		if (dirent->d_type == DT_DIR
+		    && !strncmp("cpu", dirent->d_name, 3)) {
+			long cpu = strtol(dirent->d_name + 3, NULL, 10);
+
+			if (cpu < INT_MAX && cpu > maxconfiguredcpu)
+				maxconfiguredcpu = cpu;
 		}
 	}
 	closedir(dir);
-	maxconfiguredcpu = filecount-1; /* high cpu number */
-	return;
+	if (maxconfiguredcpu < 0) {
+		/* fall back to using the online cpu count */
+		maxconfiguredcpu = sysconf(_SC_NPROCESSORS_CONF) - 1;
+	}
 }
 
 /*
lmpx.com only provides a reader for public news (NNTP) servers. It is not affiliated with the servers or forums shown here and is not responsible for the content of articles, which is written by their respective authors.