Messages in this thread | | | From | (Eric W. Biederman) | Date | Mon, 24 Feb 2014 15:43:34 -0800 | Subject | Re: [PATCH 03/11] vfs: Don't allow overwriting mounts in the current mount namespace |
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Stephen Rothwell <sfr@canb.auug.org.au> writes:
> On Tue, 18 Feb 2014 14:20:29 -0800 Linus Torvalds <torvalds@linux-foundation.org> wrote: >> >> For this kind of function return value it actually tends to work very >> well, and in fact often generates slightly better code than "int". So >> I don't _hate_ bool, and we've certainly had a lot more use creep in >> lately, but I also don't really see "bool" as much of an upside. > > And in function declarations, it makes it very obvious that the function > is not one of our "return 0 or -ERROR" ones.
So I played with this instance in particular. The only difference winds up being by the bool version uses byte instructions on %al and %bl instead of their 32 bit interger equivalents on %eax and %ebx.
I also benchmarked the difference and on the most sensitive test I could find. will-it-scale/unlink2 (aka create,close,unlink each process in a separate directory). There were no measurable performance differences.
So for purposes of better documentation I have changed the function, and I will repost my patches shortly.
Eric
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