xenpm: fix get-cpu-topology

xenpm: fix get-cpu-topology

[Wei, Gang]

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xenpm: fix get-cpu-topology

Signed-off-by: Wei Gang <gang.wei@intel.com>

diff -r cd5edc77ab93 tools/misc/xenpm.c
--- a/tools/misc/xenpm.c	Fri Jul 09 17:55:39 2010 +0800
+++ b/tools/misc/xenpm.c	Mon Jul 12 14:10:16 2010 +0800
@@ -858,7 +858,7 @@ void cpu_topology_func(int argc, char *a
         info.max_cpu_index = MAX_NR_CPU-1;
 
     printf("CPU\tcore\tsocket\tnode\n");
-    for ( i = 0; i < info.max_cpu_index; i++ )
+    for ( i = 0; i <= info.max_cpu_index; i++ )
     {
         if ( cpu_to_core[i] == INVALID_TOPOLOGY_ID )
             continue;

[-- Attachment #2: fix-xenpm-get-cpu-topology.patch --]
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xenpm: fix get-cpu-topology

Signed-off-by: Wei Gang <gang.wei@intel.com>

diff -r cd5edc77ab93 tools/misc/xenpm.c
--- a/tools/misc/xenpm.c	Fri Jul 09 17:55:39 2010 +0800
+++ b/tools/misc/xenpm.c	Mon Jul 12 14:10:16 2010 +0800
@@ -858,7 +858,7 @@ void cpu_topology_func(int argc, char *a
         info.max_cpu_index = MAX_NR_CPU-1;
 
     printf("CPU\tcore\tsocket\tnode\n");
-    for ( i = 0; i < info.max_cpu_index; i++ )
+    for ( i = 0; i <= info.max_cpu_index; i++ )
     {
         if ( cpu_to_core[i] == INVALID_TOPOLOGY_ID )
             continue;

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Re: xenpm: fix get-cpu-topology

[Ian Jackson]

Wei, Gang writes ("[Xen-devel] xenpm: fix get-cpu-topology"):
> xenpm: fix get-cpu-topology
> 
> Signed-off-by: Wei Gang <gang.wei@intel.com>
> 
> diff -r cd5edc77ab93 tools/misc/xenpm.c
> --- a/tools/misc/xenpm.c	Fri Jul 09 17:55:39 2010 +0800
> +++ b/tools/misc/xenpm.c	Mon Jul 12 14:10:16 2010 +0800
> @@ -858,7 +858,7 @@ void cpu_topology_func(int argc, char *a
>          info.max_cpu_index = MAX_NR_CPU-1;
>  
>      printf("CPU\tcore\tsocket\tnode\n");
> -    for ( i = 0; i < info.max_cpu_index; i++ )
> +    for ( i = 0; i <= info.max_cpu_index; i++ )
>      {
>          if ( cpu_to_core[i] == INVALID_TOPOLOGY_ID )
>              continue;

The comments in xen/include/public/sysctl.h about the meaning of
max_cpu_index are ambiguous:

    /*
     * IN: maximum addressable entry in the caller-provided arrays.
     * OUT: largest cpu identifier in the system.
     * If OUT is greater than IN then the arrays are truncated!
     */
    uint32_t max_cpu_index;
...
     * The size of this array is specified by the caller in @max_cpu_index.
     * If the actual @max_cpu_index is smaller than the array then the trailing
     * elements of the array will not be written by the sysctl.
     */

So is it the size of the array or the maximum index ?

Ian.

Re: xenpm: fix get-cpu-topology

[Keir Fraser]

On 12/07/2010 18:06, "Ian Jackson" <Ian.Jackson@eu.citrix.com> wrote:

>      * The size of this array is specified by the caller in @max_cpu_index.
>      * If the actual @max_cpu_index is smaller than the array then the
> trailing
>      * elements of the array will not be written by the sysctl.
>      */
> 
> So is it the size of the array or the maximum index ?

It's the maximum index. Pedantically, that is sufficient to specify the size
of the array. It is unnecessarily confusing wording though.

 -- Keir