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Subject: Re: [PATCH] IB/hfi1: Avoid allocing memory on memoryless numa node
To:     Xianting Tian <tian.xianting@h3c.com>, mike.marciniszyn@intel.com,
        dennis.dalessandro@intel.com, dledford@redhat.com, jgg@ziepe.ca
Cc:     linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org
References: <20201010085732.20708-1-tian.xianting@h3c.com>
From:   Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com>
Message-ID: <9ba33073-044c-9da6-a90d-4626e6441793@cornelisnetworks.com>
Date:   Mon, 12 Oct 2020 08:36:57 -0400
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On 10/10/2020 4:57 AM, Xianting Tian wrote:
> In architecture like powerpc, we can have cpus without any local memory
> attached to it. In such cases the node does not have real memory.
> 
> Use local_memory_node(), which is guaranteed to have memory.
> local_memory_node is a noop in other architectures that does not support
> memoryless nodes.
> 
> Signed-off-by: Xianting Tian <tian.xianting@h3c.com>
> ---
>   drivers/infiniband/hw/hfi1/file_ops.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/infiniband/hw/hfi1/file_ops.c b/drivers/infiniband/hw/hfi1/file_ops.c
> index 8ca51e43c..79fa22cc7 100644
> --- a/drivers/infiniband/hw/hfi1/file_ops.c
> +++ b/drivers/infiniband/hw/hfi1/file_ops.c
> @@ -965,7 +965,7 @@ static int allocate_ctxt(struct hfi1_filedata *fd, struct hfi1_devdata *dd,
>   	 */
>   	fd->rec_cpu_num = hfi1_get_proc_affinity(dd->node);
>   	if (fd->rec_cpu_num != -1)
> -		numa = cpu_to_node(fd->rec_cpu_num);
> +		numa = local_memory_node(cpu_to_node(fd->rec_cpu_num));
>   	else
>   		numa = numa_node_id();
>   	ret = hfi1_create_ctxtdata(dd->pport, numa, &uctxt);
> 

The hfi1 driver depends on X86_64. I'm not sure what this patch buys, 
can you expand a bit?

-Denny