Date: Fri, 2 Dec 2005 10:24:27 -0800
From: Ravikiran G Thirumalai <kiran@scalex86.org>
To: Eric Dumazet <dada1@cosmosbay.com>
Cc: Andi Kleen <ak@suse.de>, Andrew Morton <akpm@osdl.org>,
       linux-kernel@vger.kernel.org, discuss@x86-64.org, shai@scalex86.org
Subject: Re: [discuss] Re: [patch 3/3] x86_64: Node local PDA -- allocate node local memory for pda
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References: <20051202081028.GA5312@localhost.localdomain> <20051202082309.GC5312@localhost.localdomain> <43900BE3.5080000@cosmosbay.com>
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On Fri, Dec 02, 2005 at 09:54:59AM +0100, Eric Dumazet wrote:
> Ravikiran G Thirumalai a ?crit :
> >Patch uses a static PDA array early at boot and reallocates processor PDA
> >with node local memory when kmalloc is ready, just before pda_init.
> >The boot_cpu_pda is needed sice the cpu_pda is used even before pda_init 
> >for
> >that cpu is called (to set the static per-cpu areas offset table etc)
> >
> 
> That sounds great.
> 
> I have only have one suggestion : If kernel is not NUMA, then maybe we 
> should avoid one indirection to get the pda, and avoid some code too.
>

Sure, but there is no extra indirection with the fastpath routines like
read_pda, write_pda and friends with the current patch.  
Places where cpu_pda[] is accessed by the array name are not really
important -- except for the static per_cpu_offset of another cpu.  But
still it might be worth it (considering that people use 
per_cpu(var, smp_processor_id()), instead of __get_cpu_var in many places).  
I will incorporate this.

Thanks,
Kiran
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