On 11/30/2012 06:58 AM, Luck, Tony wrote: >> If any significant percentage of memory is in ZONE_MOVABLE then the memory >> hotplug people will have to deal with all the lowmem/highmem problems >> that used to be faced by 32-bit x86 with PAE enabled. > > While these problems may still exist on large systems - I think it becomes > harder to construct workloads that run into problems. In those bad old days > a significant fraction of lowmem was consumed by the kernel ... so it was > pretty easy to find meta-data intensive workloads that would push it over > a cliff. Here we are talking about systems with say 128GB per node divided > into 64GB moveable and 64GB non-moveable (and I'd regard this as a rather > low-end machine). Unless the workload consists of zillions of tiny processes > all mapping shared memory blocks, the percentage of memory allocated to > the kernel is going to be tiny compared with the old 4GB days. > Which is a perfectly common workload for containers, where you can have hundreds of machines (per node) being sold out to third parties, a lot of them consuming every single bit of metadata they can. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>