Re: [Suggestion] arch/*/include/asm/bitops.h: about __set_bit() API.

From: Geert Uytterhoeven
Date: Tue Jun 11 2013 - 03:32:46 EST

On Tue, Jun 11, 2013 at 12:26 AM, Tony Luck <tony.luck@xxxxxxxxx> wrote:
> On Sat, Jun 8, 2013 at 3:08 AM, Chen Gang <gang.chen@xxxxxxxxxxx> wrote:
>> using 'unsigned int *', implicitly:
>> ./ia64/include/asm/bitops.h:63:__set_bit (int nr, volatile void *addr)
> There is some downside on ia64 to your suggestion. If "addr" is properly
> aligned for an "int", but misaligned for a long ... i.e. addr%8 == 4, then I'll
> take an unaligned reference trap if I work with long* where the current code
> working with int* does not.
> Now perhaps all the callers do guarantee long* alignment? But I don't know.
> Apart from uniformity, there doesn't see to be any upside to changing this.

The address pointers have been supposed to be "long *" for a very long time.
Probably alpha (the second official Linux platform) did it
differently, and never
standardized to "long *".



Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
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