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Date: Mon, 31 Jul 2006 09:12:42 +0200
From: Ingo Molnar <mingo@elte.hu>
To: Paul Jackson <pj@sgi.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>,
       Srivatsa Vaddagiri <vatsa@in.ibm.com>,
       Suresh Siddha <suresh.b.siddha@intel.com>, Simon.Derr@bull.net,
       Jack Steiner <steiner@sgi.com>, linux-kernel@vger.kernel.org,
       Andrew Morton <akpm@osdl.org>
Subject: Re: [BUG] sched: big numa dynamic sched domain memory corruption
Message-ID: <20060731071242.GA31377@elte.hu>
References: <20060731070734.19126.40501.sendpatchset@v0>
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* Paul Jackson <pj@sgi.com> wrote:

> @@ -5675,12 +5675,13 @@ void build_sched_domains(const cpumask_t
>  		int group;
>  		struct sched_domain *sd = NULL, *p;
>  		cpumask_t nodemask = node_to_cpumask(cpu_to_node(i));
> +		int cpus_per_node = cpus_weight(nodemask);
>  
>  		cpus_and(nodemask, nodemask, *cpu_map);
>  
>  #ifdef CONFIG_NUMA
> -		if (cpus_weight(*cpu_map)
> -				> SD_NODES_PER_DOMAIN*cpus_weight(nodemask)) {
> +		if (cpus_weight(cpu_online_map)
> +				> SD_NODES_PER_DOMAIN*cpus_per_node) {
>  			if (!sched_group_allnodes) {
>  				sched_group_allnodes
>  					= kmalloc(sizeof(struct sched_group)

even if the bug is not fully understood in time, i think we should queue 
the patch above for v2.6.18. (with the small nit that you should put the 
new cpus_per_node variable under CONFIG_NUMA too, to avoid a compiler 
warning)

Acked-by: Ingo Molnar <mingo@elte.hu>

	Ingo