On Thu, 24 Sep 2009 02:22:15 am Alan Jenkins wrote: > [CC to lkml fixed :-/] > > Rusty Russell wrote: > > On Tue, 22 Sep 2009 10:58:28 pm Alan Jenkins wrote: > > > >> The following series applies against v2.6.31. It sorts the tables of builtin > >> symbols, so the module loader can resolve them using a binary search. > >> > >> The kbuild changes to achieve this are less scary than I expected. I'm > >> optimistic that they can be accepted without radical alteration :-). > >> > >> Quoting from the last patch in this series: > >> > >> "On my EeePC 701, coldplug is mainly cpu bound and takes 1.5 seconds > >> during boot. perf showed this change eliminated 20% of cpu cycles during > >> coldplug, saving 0.3 seconds of real time. > >> > > > > Hi Alan, > > > > This seems useful, but wouldn't it be simpler to just sort at boot time? > > The same could be done for modules, possibly reducing code. > > > > Alternately, there's a standard way of hashing ELF symbols, but I'm not sure > > we can convince the linker to generate it for vmlinux (I haven't looked > > though). > > > > Thanks! > > Rusty. > > > > I'm concerned that people would object to the extra overhead at boot > time. I've hacked up a prototype to sort at boot time and it takes 7ms > on the same hardware. OK, that seems a lot to me. Fair enough; if Sam acks the build parts, I'll put it in my tree. A bit late for this merge window though. Thanks! Rusty. -- 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
