On 15.08.2022 13:04, Juergen Gross wrote:
> For updating the node affinities of all domains in a cpupool add a new
> function cpupool_update_node_affinity().
>
> In order to avoid multiple allocations of cpumasks carve out memory
> allocation and freeing from domain_update_node_affinity() into new
> helpers, which can be used by cpupool_update_node_affinity().
>
> Modify domain_update_node_affinity() to take an additional parameter
> for passing the allocated memory in and to allocate and free the memory
> via the new helpers in case NULL was passed.
>
> This will help later to pre-allocate the cpumasks in order to avoid
> allocations in stop-machine context.
>
> Signed-off-by: Juergen Gross <jgr...@suse.com>
Reviewed-by: Jan Beulich <jbeul...@suse.com>
with the observation that ...
> --- a/xen/common/sched/core.c
> +++ b/xen/common/sched/core.c
> @@ -1824,9 +1824,28 @@ int vcpu_affinity_domctl(struct domain *d, uint32_t
> cmd,
> return ret;
> }
>
> -void domain_update_node_affinity(struct domain *d)
> +bool update_node_aff_alloc(struct affinity_masks *affinity)
> {
> - cpumask_var_t dom_cpumask, dom_cpumask_soft;
> + if ( !alloc_cpumask_var(&affinity->hard) )
> + return false;
> + if ( !alloc_cpumask_var(&affinity->soft) )
> + {
> + free_cpumask_var(affinity->hard);
> + return false;
> + }
> +
> + return true;
> +}
> +
> +void update_node_aff_free(struct affinity_masks *affinity)
> +{
> + free_cpumask_var(affinity->soft);
> + free_cpumask_var(affinity->hard);
> +}
> +
> +void domain_update_node_aff(struct domain *d, struct affinity_masks
> *affinity)
> +{
> + struct affinity_masks masks = { };
... the initializer doesn't really look to be needed here, just like
you don't have one in cpupool_update_node_affinity(). The one thing
I'm not sure about is whether old gcc might mis-report a potentially
uninitialized variable with the initializer dropped ...
Jan
