Re: [Intel-wired-lan] [Patch V3 5/9] i40e: Use numa_mem_id() to better support memoryless node

[Andrew Morton]

On Wed, 19 Aug 2015 17:18:15 -0700 (PDT) David Rientjes <rientjes@xxxxxxxxxx> wrote:

> On Wed, 19 Aug 2015, Patil, Kiran wrote:
> 
> > Acked-by: Kiran Patil <kiran.patil@xxxxxxxxx>
> 
> Where's the call to preempt_disable() to prevent kernels with preemption 
> from making numa_node_id() invalid during this iteration?

David asked this question twice, received no answer and now the patch
is in the maintainer tree, destined for mainline.

If I was asked this question I would respond

  The use of numa_mem_id() is racy and best-effort.  If the unlikely
  race occurs, the memory allocation will occur on the wrong node, the
  overall result being very slightly suboptimal performance.  The
  existing use of numa_node_id() suffers from the same issue.

But I'm not the person proposing the patch.  Please don't just ignore
reviewer comments!

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