From mboxrd@z Thu Jan  1 00:00:00 1970
From: Andi Kleen <andi@firstfloor.org>
Subject: Re: [PATCH] libnuma: disable caching of node cpusmasks
Date: Fri, 12 Jun 2015 17:30:01 +0200
Message-ID: <20150612153001.GW19417@two.firstfloor.org>
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To: Petr Holasek <pholasek@redhat.com>
Cc: linux-numa@vger.kernel.org, Filipe Brandenburger <filbranden@google.com>, Cliff Wickman <cpw@sgi.com>

> @@ -1329,25 +1321,12 @@ numa_node_to_cpus_v2(int node, struct bitmask *buffer)
>  	size_t len = 0; 
>  	struct bitmask *mask;
>  
> -	if (!node_cpu_mask_v2)
> -		init_node_cpu_mask_v2();
> -
>  	if (node > nnodes) {
>  		errno = ERANGE;
>  		return -1;
>  	}
>  	numa_bitmask_clearall(buffer);
>  
> -	if (node_cpu_mask_v2[node]) {

I was playing around with info (http://fbinfer.com/) earlier, and ran it over
numactl, and it complained about exactly this line: it can reference NULL
when the memory allocation above fails. So it's good to remove it.

Would be good to see how much performance difference it makes though.
Do you have any data? If it's significant may need to do a time out
or similar.

-Andi