lkml.org 
[lkml]   [2009]   [Jan]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 13/17] x86-64: Remove pda_init()
Brian Gerst wrote:
> On Sat, Jan 17, 2009 at 11:32 PM, Tejun Heo <tj@kernel.org> wrote:
>> 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
>> */
>
> That comment seems like overkill. It may have been relevant in an
> earlier time, but I don't think we need to be so strict now,
> especially for things we know are set properly in head_xx.S.

That may be so, but wouldn't such change deserve a separate patch with
accompanying update in the comment? It's not simple move from A to B
change.

Thanks.

--
tejun


\
 
 \ /
  Last update: 2009-01-18 06:33    [W:0.069 / U:12.392 seconds]
©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site