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

From: H. Peter Anvin
Date: Fri Dec 27 2013 - 01:10:02 EST

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.


To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at