[libvirt] [PATCH 2/2] util: numa: Stub out hugepage code on non-Linux platforms

[Michal Privoznik]

On 23.06.2014 09:29, Peter Krempa wrote:
> The hugepage sizing and counting code gathers the information from sysfs
> and thus isn't portable. Stub it out for non-Linux so that we can report
> a better error. This patch also avoids calling sysinfo() on Mingw where
> it isn't supported.
> ---
>   src/util/virnuma.c | 46 ++++++++++++++++++++++++++++++++++++++--------
>   1 file changed, 38 insertions(+), 8 deletions(-)
>
> diff --git a/src/util/virnuma.c b/src/util/virnuma.c
> index 9cf5a75..9cf9686 100644
> --- a/src/util/virnuma.c
> +++ b/src/util/virnuma.c
> @@ -512,9 +512,12 @@ virNumaGetDistances(int node ATTRIBUTE_UNUSED,
>   #endif
>
>
> -#define HUGEPAGES_NUMA_PREFIX "/sys/devices/system/node/"
> -#define HUGEPAGES_SYSTEM_PREFIX "/sys/kernel/mm/hugepages/"
> -#define HUGEPAGES_PREFIX "hugepages-"
> +/* currently all the hugepage stuff below is linux only */
> +#if WITH_LINUX
> +
> +# define HUGEPAGES_NUMA_PREFIX "/sys/devices/system/node/"
> +# define HUGEPAGES_SYSTEM_PREFIX "/sys/kernel/mm/hugepages/"
> +# define HUGEPAGES_PREFIX "hugepages-"
>
>   static int
>   virNumaGetHugePageInfoPath(char **path,
> @@ -663,7 +666,7 @@ virNumaGetPageInfo(int node,
>       /* sysconf() returns page size in bytes,
>        * the @page_size is however in kibibytes */
>       if (page_size == system_page_size / 1024) {
> -#if 0
> +# if 0
>           unsigned long long memsize, memfree;
>
>           /* TODO: come up with better algorithm that takes huge pages into
> @@ -681,11 +684,11 @@ virNumaGetPageInfo(int node,
>
>           if (page_free)
>               *page_free = memfree / system_page_size;
> -#else
> +# else
>           virReportError(VIR_ERR_ARGUMENT_UNSUPPORTED, "%s",
>                          _("system page size are not supported yet"));
>           goto cleanup;
> -#endif /* 0 */
> +# endif /* 0 */
>       } else {
>           if (virNumaGetHugePageInfo(node, page_size, page_avail, page_free) < 0)
>               goto cleanup;
> @@ -735,7 +738,7 @@ virNumaGetPages(int node,
>       size_t i;
>       bool exchange;
>
> -#if 0
> +# if 0
>       /* This has to be disabled until the time the issue in
>        * virNumaGetPageInfo is resolved. Sorry. */
>       long system_page_size;
> @@ -756,7 +759,7 @@ virNumaGetPages(int node,
>           goto cleanup;
>       tmp_size[ntmp] = system_page_size;
>       ntmp++;
> -#endif /* 0 */
> +# endif /* 0 */
>
>       /* Now that we got ordinary system pages, lets get info on huge pages */
>       if (virNumaGetHugePageInfoPath(&path, node, 0, NULL) < 0)
> @@ -844,3 +847,30 @@ virNumaGetPages(int node,
>       VIR_FREE(path);
>       return ret;

Up till here everything's okay. But ...

>   }
> +
> +
> +#else /* #if WITH_LINUX */
> +int
> +virNumaGetPageInfo(int node ATTRIBUTE_UNUSED,
> +                   unsigned int page_size ATTRIBUTE_UNUSED,
> +                   unsigned int *page_avail ATTRIBUTE_UNUSED,
> +                   unsigned int *page_free ATTRIBUTE_UNUSED)
> +{
> +    virReportError(VIR_ERR_ARGUMENT_UNSUPPORTED, "%s",
> +                   _("system page size are not supported for this platform"));
> +    return -1;
> +}
> +
> +
> +int
> +virNumaGetPages(int node ATTRIBUTE_UNUSED,
> +                unsigned int **pages_size ATTRIBUTE_UNUSED,
> +                unsigned int **pages_avail ATTRIBUTE_UNUSED,
> +                unsigned int **pages_free ATTRIBUTE_UNUSED,
> +                size_t *npages ATTRIBUTE_UNUSED)
> +{
> +    virReportError(VIR_ERR_ARGUMENT_UNSUPPORTED, "%s",
> +                   _("system page size are not supported for this platform"));
> +    return -1;
> +}
> +#endif /* #if WITH_LINUX */
>

These two APIs are intended to get info for all page sizes, not only the 
ordinary system ones.

ACK with the error message changed to reflect that.

Michal