[PATCH] libnuma: Fix issue with numactl --hardware on sparse cpumaps

[PATCH] libnuma: Fix issue with numactl --hardware on sparse cpumaps

[Anton Blanchard]

Hi,

On a machine with sparse cpu ids, numactl fails to print the right cpus:

# numactl --hardware | grep cpus
node 0 cpus: 0 2 4 6
node 1 cpus:

It turns out we were iterating through 0..nr_cpus, not 0..max_cpuid. The
following patch fixes it by using a cpumask instead of an open coded bitmask,
and looping from 0 to the size of the cpumask.

# numactl --hardware | grep cpus
node 0 cpus: 0 2 4 6
node 1 cpus: 8 10 12 14

Signed-off-by: Anton Blanchard <anton@samba.org>
---

diff -ru numactl-2.0.3~/numactl.c numactl-2.0.3/numactl.c
--- numactl-2.0.3~/numactl.c	2009-06-10 07:30:03.000000000 -0500
+++ numactl-2.0.3/numactl.c	2009-08-19 18:57:10.064311316 -0500
@@ -200,14 +200,13 @@
 
 void print_node_cpus(int node)
 {
-	int conf_cpus = numa_num_configured_cpus();
 	int i, err;
 	struct bitmask *cpus;
 
-	cpus = numa_bitmask_alloc(conf_cpus);
+	cpus = numa_allocate_cpumask();
 	err = numa_node_to_cpus(node, cpus);
 	if (err >= 0) 
-		for (i = 0; i < conf_cpus; i++) 
+		for (i = 0; i < cpus->size; i++) 
 			if (numa_bitmask_isbitset(cpus, i))
 				printf(" %d", i);
 	putchar('\n');

[PATCH] libnuma: Fix issue with numactl --hardware on sparse cpumaps

[Cliff Wickman]

Hi Anton,

Thanks for the fix.

I've started a version 2.0.4 at
ftp://oss.sgi.com/www/projects/libnuma/download/ and this is the first
patch in it.

-Cliff

> Date: Thu, 20 Aug 2009 10:10:34 +1000
> From: Anton Blanchard <anton@samba.org>
> To: linux-numa@vger.kernel.org
> Subject: [PATCH] libnuma: Fix issue with numactl --hardware on sparse cpumaps
> 
> Hi,
> 
> On a machine with sparse cpu ids, numactl fails to print the right cpus:
> 
> # numactl --hardware | grep cpus
> node 0 cpus: 0 2 4 6
> node 1 cpus:
> 
> It turns out we were iterating through 0..nr_cpus, not 0..max_cpuid. The
> following patch fixes it by using a cpumask instead of an open coded bitmask,
> and looping from 0 to the size of the cpumask.
> 
> # numactl --hardware | grep cpus
> node 0 cpus: 0 2 4 6
> node 1 cpus: 8 10 12 14
> 
> Signed-off-by: Anton Blanchard <anton@samba.org>
> ---
> 
> diff -ru numactl-2.0.3~/numactl.c numactl-2.0.3/numactl.c
> --- numactl-2.0.3~/numactl.c	2009-06-10 07:30:03.000000000 -0500
> +++ numactl-2.0.3/numactl.c	2009-08-19 18:57:10.064311316 -0500
> @@ -200,14 +200,13 @@
>  
>  void print_node_cpus(int node)
>  {
> -	int conf_cpus = numa_num_configured_cpus();
>  	int i, err;
>  	struct bitmask *cpus;
>  
> -	cpus = numa_bitmask_alloc(conf_cpus);
> +	cpus = numa_allocate_cpumask();
>  	err = numa_node_to_cpus(node, cpus);
>  	if (err >= 0) 
> -		for (i = 0; i < conf_cpus; i++) 
> +		for (i = 0; i < cpus->size; i++) 
>  			if (numa_bitmask_isbitset(cpus, i))
>  				printf(" %d", i);
>  	putchar('\n');
> 
> -- 

Cliff Wickman
SGI
cpw@sgi.com
(651) 683-3824