Messages in this thread | | | From | John David Anglin <> | Subject | Re: [PATCH] parisc:Remove unnecessary FIXMES in init.c | Date | Wed, 24 Sep 2014 08:42:37 -0400 |
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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@gmail.com> >>> --- >>> 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 >>> >>> -- >>> To unsubscribe from this list: send the line "unsubscribe linux- >>> kernel" in >>> the body of a message to majordomo@vger.kernel.org >>> More majordomo info at http://vger.kernel.org/majordomo-info.html >>> Please read the FAQ at http://www.tux.org/lkml/ >>> >>> > 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@bell.net
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