[Libvir] [RFC][PATCH 1/2] NUMA memory and topology patches

[Daniel Veillard]

On Mon, Sep 24, 2007 at 11:29:07PM -0400, beth kon wrote:
> [PATCH 1/2] - add capability to access free memory information on each 
> NUMA cell.
[...]
> diff -urpN libvirt.danielpatch/src/xen_internal.c libvirt.cellsMemory/src/xen_internal.c
> --- libvirt.danielpatch/src/xen_internal.c	2007-09-11 15:29:44.000000000 -0400
> +++ libvirt.cellsMemory/src/xen_internal.c	2007-09-24 22:04:05.000000000 -0400
[...]
>   * Returns the number of entries filled in freeMems, or -1 in case of error.
>   */
>  int
> -xenHypervisorNodeGetCellsFreeMemory(virConnectPtr conn, unsigned long *freeMems,
> -                                    int nbCells)
> +xenHypervisorNodeGetCellsFreeMemory(virConnectPtr conn, long long *freeMems,
> +                                    int startCell, int maxCells)
>  {
> -    if ((conn == NULL) || (freeMems == NULL) || (nbCells < 0))
> -        return -1;
> +    xen_op_v2_sys op_sys;
> +    int i, j, ret;
> +    xenUnifiedPrivatePtr priv;
> +    
>  
> +    if ((conn == NULL) || (maxCells < 1) || (startCell > nbNodeCells)) {
> +        virXenErrorFunc (VIR_ERR_INVALID_ARG, __FUNCTION__,
> +                        "invalid argument", 0);
> +        return -1;
> +    }
>      /*
> -     * TODO:
> -     *   - get the number of cell in the node
> -     *   - if not NUMA returns the available memeoy directly in freeMems[0]
> -     *     return 1
> -     *   - if NUMA iterates over the cells using a specific hypercall
> -     *     filling up entries until full or at the end of the NUMA cells
> +     * Support only sys_interface_version >=4
>       */
> -    return(-1);
> +    if (sys_interface_version < 4) {
> +        virXenErrorFunc (VIR_ERR_NO_XEN, __FUNCTION__,
> +                        "unsupported in sys interface < 4", 0);
> +        return -1;
> +    }

   I found out that using VIR_ERR_NO_XEN here isn't a good idea, first
it's not that Xen hypervisoris not found but that this specific call is not
available, and second virsh filter out automatically VIR_ERR_NO_XEN. It
is better to use VIR_ERR_XEN_CALL , you then get:

[root at test2 src]# ./virsh freecell 1
libvir: Xen error : failed Xen syscall xenHypervisorNodeGetCellsFreeMemory: unsupported in sys interface < 4 0

[root at test2 src]# echo $?
1
[root at test2 src]# 

  Which is a correct error report IMHO.

Daniel

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Daniel Veillard      | virtualization library  http://libvirt.org/
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