* Andi Kleen <andi@xxxxxxxxxxxxxx> wrote: > This rather large patchkit enables gcc Link Time Optimization (LTO) > support for the kernel. > > With LTO gcc will do whole program optimizations for > the whole kernel and each module. This increases compile time, > but can generate faster code. By how much does it increase compile time? How much faster does kernel code get? Last time I checked LTO optimizations (half a year ago) it resulted in significantly slower build times. I tried out and measured the LTO speedups and was less than impressed by them - a lot of build time increase for not much increase in performance. There was also visible, ongoing maintenance cost. The combination of these seemed like a show-stopper. It's obviously an optimization feature we should consider, but we really need hard numbers to make a cost/benefit analysis. Thanks, Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
