Re: [RFC PATCH V2 11/22] x86/intel_rdt: Associate pseudo-locked regions with its domain

From: Thomas Gleixner
Date: Mon Feb 19 2018 - 16:20:46 EST


On Tue, 13 Feb 2018, Reinette Chatre wrote:

> After a pseudo-locked region is locked it needs to be associated with
> the RDT domain representing the pseudo-locked cache so that its life
> cycle can be managed correctly.
>
> Only a single pseudo-locked region can exist on any cache instance so we
> maintain a single pointer to a pseudo-locked region from each RDT
> domain.

Why is only a single pseudo locked region possible?

> Signed-off-by: Reinette Chatre <reinette.chatre@xxxxxxxxx>
> ---
> arch/x86/kernel/cpu/intel_rdt.h | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/arch/x86/kernel/cpu/intel_rdt.h b/arch/x86/kernel/cpu/intel_rdt.h
> index 060a0976ac00..f0e020686e99 100644
> --- a/arch/x86/kernel/cpu/intel_rdt.h
> +++ b/arch/x86/kernel/cpu/intel_rdt.h
> @@ -187,6 +187,8 @@ struct mbm_state {
> u64 prev_msr;
> };
>
> +struct pseudo_lock_region;
> +
> /**
> * struct rdt_domain - group of cpus sharing an RDT resource
> * @list: all instances of this resource
> @@ -205,6 +207,7 @@ struct mbm_state {
> * @ctrl_val: array of cache or mem ctrl values (indexed by CLOSID)
> * @new_ctrl: new ctrl value to be loaded
> * @have_new_ctrl: did user provide new_ctrl for this domain
> + * @plr: pseudo-locked region associated with this domain
> */
> struct rdt_domain {
> struct list_head list;
> @@ -220,6 +223,7 @@ struct rdt_domain {
> u32 *ctrl_val;
> u32 new_ctrl;
> bool have_new_ctrl;
> + struct pseudo_lock_region *plr;

Please keep the tabular fashion of the struct declaration intact.

Thanks,

tglx