On Fri, Mar 08, 2019 at 07:35:17PM +0000, Nadav Amit wrote: > Nice script! I keep asking myself how comparing two binaries can provide > some “number” to indicate how “good” the binary is (at least relatively to > another one) - either during compilation or after. Code size, as you show, > is the wrong metric.
Right; I'm still pondering other metrics, like: readelf -WS | grep AX | grep -v -e init -e exit -e altinstr -e unlikely -e fixup which is only 'fast' path text. > Anyhow, I am a little disappointed (and surprised) that in most cases that I > played with, this kind of optimizations have marginal impact on performance > at best, even when the binary changes “a lot” and when microbenchmarks are > used. Right, but if we don't care, it'll be death by 1000 cuts. Anyway, can anybody explain percpu_stable_op() vs percpu_from_op() ? I'm thinking of a variant of Linus' patch, but I'm confused about the above.
