Re: [PATCH v2 8/9] mips: numa: check the node id consistently for mips ip27

From: Paul Burton <paul.burton@mips.com>
To: Yunsheng Lin <linyunsheng@huawei.com>
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Subject: Re: [PATCH v2 8/9] mips: numa: check the node id consistently for mips ip27
Date: Sat, 31 Aug 2019 15:45:52 +0000	[thread overview]
Message-ID: <20190831154547.qzh6j4jwg5o5y4db@pburton-laptop> (raw)
In-Reply-To: <1567231103-13237-9-git-send-email-linyunsheng@huawei.com>

Hi Yunsheng,

On Sat, Aug 31, 2019 at 01:58:22PM +0800, Yunsheng Lin wrote:
> According to Section 6.2.14 from ACPI spec 6.3 [1], the setting
> of proximity domain is optional, as below:
> 
> This optional object is used to describe proximity domain
> associations within a machine. _PXM evaluates to an integer
> that identifies a device as belonging to a Proximity Domain
> defined in the System Resource Affinity Table (SRAT).
> 
> Since mips ip27 uses hub_data instead of node_to_cpumask_map,
> this patch checks node id with the below case before returning
> &hub_data(node)->h_cpus:
> 1. if node_id >= MAX_COMPACT_NODES, return cpu_none_mask
> 2. if node_id < 0, return cpu_online_mask
> 3. if hub_data(node) is NULL, return cpu_online_mask
> 
> [1] https://uefi.org/sites/default/files/resources/ACPI_6_3_final_Jan30.pdf

Similar to David's comment on the sparc patch, these systems don't use
ACPI so I don't see from your commit message why this change would be
relevant.

This same comment applies to patch 9 too.

Thanks,
    Paul

> 
> Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
> ---
>  arch/mips/include/asm/mach-ip27/topology.h | 15 ++++++++++++---
>  1 file changed, 12 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/mips/include/asm/mach-ip27/topology.h b/arch/mips/include/asm/mach-ip27/topology.h
> index 965f079..914a55a 100644
> --- a/arch/mips/include/asm/mach-ip27/topology.h
> +++ b/arch/mips/include/asm/mach-ip27/topology.h
> @@ -15,9 +15,18 @@ struct cpuinfo_ip27 {
>  extern struct cpuinfo_ip27 sn_cpu_info[NR_CPUS];
>  
>  #define cpu_to_node(cpu)	(sn_cpu_info[(cpu)].p_nodeid)
> -#define cpumask_of_node(node)	((node) == -1 ?				\
> -				 cpu_all_mask :				\
> -				 &hub_data(node)->h_cpus)
> +
> +static inline const struct cpumask *cpumask_of_node(int node)
> +{
> +	if (node >= MAX_COMPACT_NODES)
> +		return cpu_none_mask;
> +
> +	if (node < 0 || !hub_data(node))
> +		return cpu_online_mask;
> +
> +	return &hub_data(node)->h_cpus;
> +}
> +
>  struct pci_bus;
>  extern int pcibus_to_node(struct pci_bus *);
>  
> -- 
> 2.8.1
> 