On 2015.04.12 at 12:14 +0200, Ingo Molnar wrote: > In my (past) experience the main win from -flto is not due to better > hot/cold decisions, but simply due to more aggressive dead code > elimination. -flto has less of an effect on code that is actually > being executed. > > Which isn't to be sneered at, but it's far less of a direct effect as > branch probabilities are, which cut to the core of most hotpaths in > the kernel.
I did some measurements with gcc-5.1-RC on X86_64 using Andi's latest LTO kernel patch for 4.0. With my simple monolithic .config the code size savings are below 1%. That is lower than I've expected. -- Markus -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
