On Fri, Jun 21, 2013 at 01:28:11PM -0700, Yinghai Lu wrote: > On Fri, Jun 21, 2013 at 12:19 PM, Nathan Zimmer <nzimmer@xxxxxxx> wrote: > > On 06/21/2013 02:10 PM, Yinghai Lu wrote: > >> in this way we can keep all numa etc on the place when online ram, cpu, > >> pci... > >> > >> For example if we have 32 sockets system, most time for boot is with > >> *BIOS* > >> instead of OS. In those kind of system boot is like this way: > >> only first two sockets get booted from bios to OS. > >> later use hot add every other two sockets. > >> > >> that will also make BIOS simpler, and it need to support hot-add for > >> services purpose anyway. > >> > > Yes the hot add path was one option we looked at and it did shorten boot > > times but the goal I had here is to get from power on to having the full > > machine available as quick as possible. Several clients need significant > > portions of ram for their key workloads. So that guided my thoughts on this > > patch. > > you mean boot small number sockets + hot add still take more time? > hot add ram still in serialize mode? > > Yinghai Yes the hot add path is still fairly serial. lock_memory_hotplug() is still a global lock, which effectivly serializes online pages. Since the hotplug lock could done per node but for that to be effective something would need to be done with lock_system_sleep() since is called by lock_memory_hotplug(). Nate -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
