On Fri, Jun 21, 2013 at 11:50 AM, Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:On Fri, Jun 21, 2013 at 11:44:22AM -0700, Yinghai Lu wrote:I mean for Intel cpu have cpu and memory controller and IIO.On Fri, Jun 21, 2013 at 10:03 AM, H. Peter Anvin <hpa@xxxxxxxxx> wrote:What exactly do you mean by "after boot"? Often, the boot process ofOn 06/21/2013 09:51 AM, Greg KH wrote:I would suggest another way:
I suspect the cutoff for this should be a lot lower than 8 TB even, more
like 128 GB or so. The only concern is to not set the cutoff so low
that we can end up running out of memory or with suboptimal NUMA
placement just because of this.
only boot the system with boot node (include cpu, ram and pci root buses).
then after boot, could add other nodes.
userspace needs those additional cpus and ram in order to initialize
everything (like the pci devices) properly.
every IIO is one peer pci root bus.
So scan root bus that are not with boot node later.
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.