Re: [PATCH 1/2] xen/mm: Alter get_outstanding_claims() to return information by value

On 03.08.2026 14:17, Andrew Cooper wrote:
> A void function with two output parameters is a weird choice.  Instead, return
> a two-element structure.

Hmm. Generally in reviews I'm trying to recommend against returning of structures
by value. I don't like this very much here either, and it is (slightly) harder to
use ...

> --- a/xen/common/sysctl.c
> +++ b/xen/common/sysctl.c
> @@ -248,6 +248,7 @@ long do_sysctl(XEN_GUEST_HANDLE_PARAM(xen_sysctl_t) u_sysctl)
>      case XEN_SYSCTL_physinfo:
>      {
>          struct xen_sysctl_physinfo *pi = &op->u.physinfo;
> +        claim_info_t claim_info;
>  
>          memset(pi, 0, sizeof(*pi));
>          pi->threads_per_core =
> @@ -259,8 +260,11 @@ long do_sysctl(XEN_GUEST_HANDLE_PARAM(xen_sysctl_t) u_sysctl)
>          pi->max_node_id = MAX_NUMNODES-1;
>          pi->max_cpu_id = nr_cpu_ids - 1;
>          pi->total_pages = total_pages;
> -        /* Protected by lock */
> -        get_outstanding_claims(&pi->free_pages, &pi->outstanding_pages);
> +
> +        claim_info = get_outstanding_claims();
> +        pi->free_pages = claim_info.avail;
> +        pi->outstanding_pages = claim_info.claimed;

... here. If others think this is the way to go, so be it. But I'm not in favor.

Jan