[PATCH 1/1] lscpu: support discontinuous NUMA nodes

[PATCH 1/1] lscpu: support discontinuous NUMA nodes

[Madhavan Srinivasan]

lscpu fails to print proper NUMA node values in a system
with discontinuous nodes. This patch adds support by
creating a nodeidx array to map node numbers.

Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
---
 sys-utils/lscpu.c |   47 +++++++++++++++++++++++++++++++++++++++++------
 1 file changed, 41 insertions(+), 6 deletions(-)

diff --git a/sys-utils/lscpu.c b/sys-utils/lscpu.c
index 8f14b3a..6683aff 100644
--- a/sys-utils/lscpu.c
+++ b/sys-utils/lscpu.c
@@ -50,6 +50,7 @@
 /* /sys paths */
 #define _PATH_SYS_SYSTEM	"/sys/devices/system"
 #define _PATH_SYS_CPU		_PATH_SYS_SYSTEM "/cpu"
+#define _PATH_SYS_NODE		_PATH_SYS_SYSTEM "/node"
 #define _PATH_PROC_XEN		"/proc/xen"
 #define _PATH_PROC_XENCAP	_PATH_PROC_XEN "/capabilities"
 #define _PATH_PROC_CPUINFO	"/proc/cpuinfo"
@@ -177,6 +178,7 @@ struct lscpu_desc {
 	int		*idx2cpunum;	/* mapping index to CPU num */
 
 	int		nnodes;		/* number of NUMA modes */
+	int		*idx2nodenum;	/* Support for discontinuous nodes */
 	cpu_set_t	**nodemaps;	/* array with NUMA nodes */
 
 	/* books -- based on book_siblings (internal kernel map of cpuX's
@@ -912,25 +914,58 @@ read_cache(struct lscpu_desc *desc, int idx)
 	}
 }
 
+static int
+check_for_dir(const char *path, const char *file_name)
+{
+	char buf[100];
+	struct stat file;
+
+	sprintf(buf, "%s/%s", path, file_name);
+	return stat(buf, &file) == 0 && S_ISDIR(file.st_mode);
+}
+
 static void
 read_nodes(struct lscpu_desc *desc)
 {
-	int i;
+	int i=0;
+	DIR *dir=NULL;
+	struct dirent *curdir=NULL;
 
 	/* number of NUMA node */
-	while (path_exist(_PATH_SYS_SYSTEM "/node/node%d", desc->nnodes))
-		desc->nnodes++;
+	dir=opendir(_PATH_SYS_NODE);
+	if(dir) {
+		while ((curdir = readdir(dir)) != NULL) {
+			if((strncmp(curdir->d_name, "node", 4) == 0) &&
+			    check_for_dir(_PATH_SYS_NODE, curdir->d_name) &&
+			    isdigit_string(curdir->d_name + 4) )
+				desc->nnodes++;
+			}
+		closedir(dir);
+	}
 
 	if (!desc->nnodes)
 		return;
 
 	desc->nodemaps = xcalloc(desc->nnodes, sizeof(cpu_set_t *));
+	desc->idx2nodenum = xmalloc(desc->nnodes * sizeof(int));
+
+	dir=opendir(_PATH_SYS_NODE);
+	if(dir) {
+		while ((curdir = readdir(dir)) != NULL) {
+			if( (strncmp(curdir->d_name, "node", 4) == 0) &&
+			    check_for_dir(_PATH_SYS_NODE, curdir->d_name) &&
+			    isdigit_string(curdir->d_name + 4) )
+				desc->idx2nodenum[i++] = strtol_or_err(((curdir->d_name)+4),
+							_("Failed to extract the node number"));
+			}
+		closedir(dir);
+	}
 
 	/* information about how nodes share different CPUs */
 	for (i = 0; i < desc->nnodes; i++)
 		desc->nodemaps[i] = path_read_cpuset(maxcpus,
 					_PATH_SYS_SYSTEM "/node/node%d/cpumap",
-					i);
+					desc->idx2nodenum[i]);
 }
 
 static char *
@@ -961,7 +996,7 @@ get_cell_data(struct lscpu_desc *desc, int idx, int col,
 	case COL_NODE:
 		if (cpuset_ary_isset(cpu, desc->nodemaps,
 				     desc->nnodes, setsize, &i) == 0)
-			snprintf(buf, bufsz, "%zd", i);
+			snprintf(buf, bufsz, "%d", desc->idx2nodenum[i]);
 		break;
 	case COL_BOOK:
 		if (cpuset_ary_isset(cpu, desc->bookmaps,
@@ -1378,7 +1413,7 @@ print_summary(struct lscpu_desc *desc, struct lscpu_modifier *mod)
 	}
 
 	for (i = 0; i < desc->nnodes; i++) {
-		snprintf(buf, sizeof(buf), _("NUMA node%d CPU(s):"), i);
+		snprintf(buf, sizeof(buf), _("NUMA node%d CPU(s):"), desc->idx2nodenum[i]);
 		print_cpuset(buf, desc->nodemaps[i], mod->hex);
 	}
 }
-- 
1.7.10.4

Re: [PATCH 1/1] lscpu: support discontinuous NUMA nodes

[Karel Zak]

On Thu, Jan 02, 2014 at 03:14:37PM +0530, Madhavan Srinivasan wrote:
> lscpu fails to print proper NUMA node values in a system
> with discontinuous nodes. This patch adds support by
> creating a nodeidx array to map node numbers.

Good idea. It would be also nice to have a /sys dump from system
with discontinuous nodes. You can generate the dump by

  tests/ts/lscpu/mk-input.sh  foo

and send me foo.tar.gz. I'll add the dump to lscpu(1) regression
tests.

>  sys-utils/lscpu.c |   47 +++++++++++++++++++++++++++++++++++++++++------

I have applied a little different patch..

> +static int
> +check_for_dir(const char *path, const char *file_name)
> +{
> +	char buf[100];
> +	struct stat file;
> +
> +	sprintf(buf, "%s/%s", path, file_name);

this is exactly reason why we have openat/statat/... functions.

> +	return stat(buf, &file) == 0 && S_ISDIR(file.st_mode);
> +}

>  static void
>  read_nodes(struct lscpu_desc *desc)
>  {
> -	int i;
> +	int i=0;
> +	DIR *dir=NULL;
> +	struct dirent *curdir=NULL;
>  
>  	/* number of NUMA node */
> -	while (path_exist(_PATH_SYS_SYSTEM "/node/node%d", desc->nnodes))
> -		desc->nnodes++;
> +	dir=opendir(_PATH_SYS_NODE);
> +	if(dir) {
> +		while ((curdir = readdir(dir)) != NULL) {
> +			if((strncmp(curdir->d_name, "node", 4) == 0) &&
> +			    check_for_dir(_PATH_SYS_NODE, curdir->d_name) &&

 anyway, you can use dirent->d_type to avoid unnecessary stat()

 Thanks!

    Karel

-- 
 Karel Zak  <kzak@redhat.com>
 http://karelzak.blogspot.com