Re: [RFC v3 0/5] Transparent on-demand struct page initialization embedded in the buddy allocator

Nathan Zimmer
2013-08-13T21:35:05Z

On 08/13/2013 01:04 PM, Mike Travis wrote:
>
> On 8/13/2013 10:51 AM, Linus Torvalds wrote:
>> by the time you can log in. And if it then takes another ten minutes
>> until you have the full 16TB initialized, and some things might be a
>> tad slower early on, does anybody really care? The machine will be up
>> and running with plenty of memory, even if it may not be *all* the
>> memory yet.
> Before the patches adding memory took ~45 mins for 16TB and almost 2 hours
> for 32TB. Adding it late sped up early boot but late insertion was still
> very slow, where the full 32TB was still not fully inserted after an hour.
> Doing it in parallel along with the memory hotplug lock per node, we got
> it down to the 10-15 minute range.
Yes but to get it to the 10-15 minute range I had to change an number of
system locks.
The system_sleep, the memory_hotplug, zonelist_mutex and there was some
general alteration
to various wmark routines.
Some of those fixes I don't know if they would stand up to proper
scrutiny but were quick and dirty
hacks to allow for progress.

Nate