Re: [PATCH 13/17] x86-64: Remove pda_init()

From: Tejun Heo
Date: Sat Jan 17 2009 - 23:33:07 EST


Hello,

Brian Gerst wrote:
> -void __cpuinit pda_init(int cpu)
> -{
> - struct x8664_pda *pda = cpu_pda(cpu);
> -
> - /* Setup up data that may be needed in __get_free_pages early */
> - loadsegment(fs, 0);
> - loadsegment(gs, 0);
> -
> - load_pda_offset(cpu);
> -}

Simply removing these should work fine as they're also initialized in
other places earlier but I think they still need to be in cpu_init()
because...

/*
* cpu_init() initializes state that is per-CPU. Some data is already
* initialized (naturally) in the bootstrap process, such as the GDT
* and IDT. We reload them nevertheless, this function acts as a
^^^^^^^^^^^^^^^^^^^^^^^^^^^
* 'CPU state barrier', nothing should get across.
* A lot of state is already set up in PDA init for 64 bit
*/

Thanks.

--
tejun
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