On 04/29/2011 07:05 PM, Andi Kleen wrote:
> Do you think the following case would not differ so much > from (1' 2') ? > > walk_addr_generic() ---1'' > copy_from_user() ---2''Yes it should be the same and is cleaner. If you do a make .../foo.i and look at the code coming out of the preprocessor you'll see it expands to a if (!__builtin_constant_p(size)) return copy_user_generic(dst, (__force void *)src, size); switch (size) { case 1:__get_user_asm(*(u8 *)dst, (u8 __user *)src, ret, "b", "b", "=q", 1); return ret; case 2: .. case 4: .. case 8: .. case 10: .. case 16: .. } Ok it looks like the 32bit kernel only handles 1/2/4. Maybe that was the problem if you ran on 32bit.
I'm happy with a slower copy_from_user() for that particular case. -- error compiling committee.c: too many arguments to function -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
