Re: reorganized struct inode results in unaligned accesses

From: David Miller
Date: Sun Jun 19 2011 - 19:02:13 EST


From: Andi Kleen <andi@xxxxxxxxxxxxxx>
Date: Sun, 19 Jun 2011 15:35:30 -0700

> Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> writes:
>>
>> Dang. I guess it needs to be made "unsigned long" again. Which is a
>> shame, because we only use a couple of bits from there, and "struct
>> inode" really is much too big already.
>
> In the past it was usually enough to just align it to alignof(unsigned
> long), not actually make it long. struct page went through this
> a long time ago.

Hmmm, can this scheme actually work out properly on both big and
little endian? Because endianness determines whether the bits start
in the "lower addressed" 32-bit word or the "higher addressed" 32-bit
word.

If this trick is being attempted elsewhere, I think it could perhaps
account for some strange bugs :-)
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/