On Sat, May 09, 2015 at 12:45:01AM +0200, Rasmus Villemoes wrote: > attribute((cold)) causes gcc to optimize the function for size rather > than speed. But since __init functions will be discarded anyway, I > don't see why memory should be a concern. On the contrary, everybody
It makes the bzImage smaller. A lot of people on smaller systems are interested in flash size. > wants their box to boot faster. Using the opposite attribute, hot, > causes gcc to optimize the functions more aggressively, possibly at > the expense of larger (.init).text. A completely unscientific test > showed about 2% faster boot time: I booted a kernel in qemu with and > without this patch five times each; the boot times were very stable in > each case, so I think the 2% is ok, but of course only applies to that > specific .config running in a virtual machine on my hardware. 2% on boot is basically noise. -Andi -- 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/
