Re: [RFC] speeding up the stat() family of system calls...

[H. Peter Anvin]

On 12/26/2013 10:09 PM, H. Peter Anvin wrote:
> On 12/26/2013 11:00 AM, Linus Torvalds wrote:
>>
>> Interestingly, looking at the cp_new_stat() profiles, the games we
>> play to get efficient range checking seem to actually hurt us. Maybe
>> it's the "sbb" that is just expensive, or maybe it's turning a (very
>> predictable) conditional branch into a data dependency chain instead.
>> Or maybe it's just random noise in my profiles that happened to make
>> those sbb's look bad.
>>
> 
> Much to my surprise, this patch adds almost 10K of text to an
> "allyesconfig" build.  I wouldn't have expected it.  I'll look at it
> some more tomorrow.
> 

Mystery solved... it is all code added by gcov &c because a new (inline)
function is added to the code base.  So it is fluff, not real.

	-hpa


--
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/