On Mon, Apr 28, 2014 at 10:48:13AM +0800, Jiang Liu wrote: > Intel platforms with Nehalem/Westmere/IvyBridge CPUs may support socket > hotplug/online at runtime. The CPU hot-addition flow is: > 1) handle CPU hot-addition event > 1.a) gather platform specific information > 1.b) associate hot-added CPU with NUMA node > 1.c) create CPU device > 2) online hot-added CPU through sysfs: > 2.a) cpu_up() > 2.b) ->try_online_node() > 2.c) ->hotadd_new_pgdat() > 2.d) ->node_set_online() > > Between 1.b and 2.c, hot-added CPUs are associated with NUMA nodes > but those NUMA nodes may still be in offlined state. So we should > check node_online(nid) before calling kmalloc_node(nid) and friends, > otherwise it may cause invalid memory access as below.
So complete and full NAK on this. This is a workaround for a fucked in the head BIOS. If you're going to do a work around for that they should live in arch/ space, not in core code. The code in question is nearly 7 years old (2.6.24), which leads me to believe it works just fine for (regular) memory less nodes as I've not had complaints about it before. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
