Re: [PATCH] parisc:Remove unnecessary FIXMES in init.c

From: Nicholas Krause
Date: Wed Sep 24 2014 - 10:29:46 EST


On Wed, Sep 24, 2014 at 8:42 AM, John David Anglin <dave.anglin@xxxxxxxx> wrote:
> On 24-Sep-14, at 7:42 AM, nick wrote:
>
>>
>>
>> On 14-09-24 01:30 AM, Guenter Roeck wrote:
>>>
>>> On Tue, Sep 23, 2014 at 09:49:43PM -0400, Nicholas Krause wrote:
>>>>
>>>> This removes the two fixmes in the file, init.c for compiler hints
>>>> for comments related to compiler hints in linux_gateway_page_addr
>>>> and map_hpux_gateway_page to change from FIXME to HINT in order
>>>> for people reading this code to understand that these are compiler
>>>> hints.
>>>>
>>>
>>> "* const" tells the compiler that a pointer is a constant.
>>> It doesn't tell the compiler that the data shall not be treated
>>> as DP-relative.
>>>
>>> FIXME as in: We should find a better way to tell the compiler to
>>> not treat this data as DP-relative.
>>>
>>> Can you please stop this ?
>>>
>>> Guenter
>>>
>>>> Signed-off-by: Nicholas Krause <yocto6@xxxxxxxxx>
>>>> ---
>>>> arch/parisc/mm/init.c | 4 ++--
>>>> 1 file changed, 2 insertions(+), 2 deletions(-)
>>>>
>>>> diff --git a/arch/parisc/mm/init.c b/arch/parisc/mm/init.c
>>>> index 0bef864..668102e 100644
>>>> --- a/arch/parisc/mm/init.c
>>>> +++ b/arch/parisc/mm/init.c
>>>> @@ -733,7 +733,7 @@ static void __init pagetable_init(void)
>>>> static void __init gateway_init(void)
>>>> {
>>>> unsigned long linux_gateway_page_addr;
>>>> - /* FIXME: This is 'const' in order to trick the compiler
>>>> + /* HINT: This is 'const' in order to trick the compiler
>>>> into not treating it as DP-relative data. */
>>>> extern void * const linux_gateway_page;
>>>>
>>>> @@ -761,7 +761,7 @@ map_hpux_gateway_page(struct task_struct *tsk,
>>>> struct mm_struct *mm)
>>>> unsigned long start_pte;
>>>> unsigned long address;
>>>> unsigned long hpux_gw_page_addr;
>>>> - /* FIXME: This is 'const' in order to trick the compiler
>>>> + /* HINT: This is 'const' in order to trick the compiler
>>>> into not treating it as DP-relative data. */
>>>> extern void * const hpux_gateway_page;
>>>>
>>>> --
>>>> 1.9.1
>>>>
>>>> --
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>>>>
>>>>
>> Guenter,
>> I asked the maintainers and I got,
>> On 9/23/2014 4:48 PM, Helge Deller wrote:
>>>
>>> The FIXME: is misleading. It should maybe better read "HINT:" or
>>> something like that.
>>> Trivially it's basically just casting the symbol so that the compiler
>>> will produce the correct code later on.
>>> There is nothing you could try to "fix".
>>
>> Why not just remove "FIXME: " from these comments?
>
>
>
> The wording of the comment is not good. You can't "trick" the compiler into
> not
> treating a constant as DP-relative data. Whether or not a constant is
> loaded as an
> immediate depends on its value.
>
> Dave
> --
> John David Anglin dave.anglin@xxxxxxxx
>
>
>
Are stating I need to change the wording of my commit or the comment?
Nick
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