On Fri, Jan 23, 2015 at 07:46:43AM -0800, Guenter Roeck wrote: > I added some debugging. First, the problem is only seen with SMP disabled. > Second, there is only one online node. > > Without your patch: > > Node 0 online 1 high 1 memory 1 cpu 0 normal 1 tmp 0 rtpn c00000003d240600 > Node 1 online 0 high 0 memory 0 cpu 0 normal 0 tmp -1 rtpn c00000003d240640 > Node 2 online 0 high 0 memory 0 cpu 0 normal 0 tmp -1 rtpn c00000003d240680 > > [ and so on up to node 255 ] > > With your patch: > > Node 0 online 1 high 1 memory 1 cpu 0 normal 1 rtpn c00000003d240600 > Unable to handle kernel paging request for data at address 0x0000af50 > Faulting instruction address: 0xc000000000895a3c > Oops: Kernel access of bad area, sig: 11 [#1] > > The log message is after the call to kzalloc_node. > > So it doesn't look like the fallback is working, at least not with ppc64 > in non-SMP mode. Yep, and Christoph confirmed that it's not meant to work like that. The patch is flawed. Thanks for testing and sorry for breaking your setup. -- 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>