On 25.10.16 14:31:00, David Daney wrote: > From: David Daney <david.daney@xxxxxxxxxx> > > On arm64 NUMA kernels we can pass "numa=off" on the command line to > disable NUMA. A side effect of this is that kmalloc_node() calls to > non-zero nodes will crash the system with an OOPS: > > [ 0.000000] [<fffffc00081bba84>] __alloc_pages_nodemask+0xa4/0xe68 > [ 0.000000] [<fffffc00082163a8>] new_slab+0xd0/0x57c > [ 0.000000] [<fffffc000821879c>] ___slab_alloc+0x2e4/0x514 > [ 0.000000] [<fffffc000823882c>] __slab_alloc+0x48/0x58 > [ 0.000000] [<fffffc00082195a0>] __kmalloc_node+0xd0/0x2e0 > [ 0.000000] [<fffffc00081119b8>] __irq_domain_add+0x7c/0x164 > [ 0.000000] [<fffffc0008b75d30>] its_probe+0x784/0x81c > [ 0.000000] [<fffffc0008b75e10>] its_init+0x48/0x1b0 > . > . > . > > This is caused by code like this in kernel/irq/irqdomain.c > > domain = kzalloc_node(sizeof(*domain) + (sizeof(unsigned int) * size), > GFP_KERNEL, of_node_to_nid(of_node)); > > When NUMA is disabled, the concept of a node is really undefined, so > of_node_to_nid() should unconditionally return NUMA_NO_NODE. > > Add __of_force_no_numa() to allow of_node_to_nid() to be forced to > return NUMA_NO_NODE. > > The follow on patch will call this new function from the arm64 numa > code. Didn't that work before? numa=off just maps all mem to node 0. If mem allocation is requested for another node it should just fall back to a node with mem (node 0 then). I suspect there is something wrong with the page initialization, see: http://www.spinics.net/lists/arm-kernel/msg535191.html https://bugzilla.redhat.com/show_bug.cgi?id=1387793 What is the complete oops? So I think k*alloc_node() must be able to handle requests to non-existing nodes. Otherwise your fix is incomplete, assume a failed of_numa_init() causing a dummy init but still some devices reporting a node. -Robert -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
