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Date: Tue, 27 Oct 2009 21:08:46 -0700 (PDT)
From: David Rientjes <rientjes@google.com>
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To: Andi Kleen <andi@firstfloor.org>
cc: Ingo Molnar <mingo@elte.hu>, Mike Travis <travis@sgi.com>,
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       Mel Gorman <mel@csn.ul.ie>, linux-kernel@vger.kernel.org,
       linux-acpi@vger.kernel.org
Subject: Re: [patch] x86: reduce srat verbosity in the kernel log
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On Wed, 28 Oct 2009, Andi Kleen wrote:

> > +static DECLARE_BITMAP(apicid_map, MAX_LOCAL_APIC) __initdata;
> > +static char apicid_list[MAX_LOCAL_APIC] __initdata;
> 
> Is MAX_LOCAL_APIC really big enough to print them all in ASCII?
> 
> It would be better to not use that large a buffer, but print
> in smaller pieces (I realize this would enlarge your patch,
> but then it would also save a lot of BSS)
> 

MAX_LOCAL_APIC was definitely an arbitrary choice here and has very little 
relevance.  scnlistprintf will protect against overflow, but we still need 
to decide upon a constant that will emit the most information possible 
while not overly polluting the printk and saving on bss, as you mentioned.  
I suspect we could agree on a value as little as 128 and it would work for 
the overwhelming majority (all?) of users.