On 23.07.2014 [16:20:24 +0800], Jiang Liu wrote: > > > On 2014/7/22 1:57, Nishanth Aravamudan wrote: > > On 21.07.2014 [10:41:59 -0700], Tony Luck wrote: > >> On Mon, Jul 21, 2014 at 10:23 AM, Nishanth Aravamudan > >> <nacc@xxxxxxxxxxxxxxxxxx> wrote: > >>> It seems like the issue is the order of onlining of resources on a > >>> specific x86 platform? > >> > >> Yes. When we online a node the BIOS hits us with some ACPI hotplug events: > >> > >> First: Here are some new cpus > > > > Ok, so during this period, you might get some remote allocations. Do you > > know the topology of these CPUs? That is they belong to a > > (soon-to-exist) NUMA node? Can you online that currently offline NUMA > > node at this point (so that NODE_DATA()) resolves, etc.)? > Hi Nishanth, > We have method to get the NUMA information about the CPU, and > patch "[RFC Patch V1 30/30] x86, NUMA: Online node earlier when doing > CPU hot-addition" tries to solve this issue by onlining NUMA node > as early as possible. Actually we are trying to enable memoryless node > as you have suggested. Ok, it seems like you have two sets of patches then? One is to fix the NUMA information timing (30/30 only). The rest of the patches are general discussions about where cpu_to_mem() might be used instead of cpu_to_node(). However, based upon Tejun's feedback, it seems like rather than force all callers to use cpu_to_mem(), we should be looking at the core VM to ensure fallback is occuring appropriately when memoryless nodes are present. Do you have a specific situation, once you've applied 30/30, where kmalloc_node() leads to an Oops? Thanks, Nish -- 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>