Re: lockdep warning while booting POWER9 PowerNV

From: Bart Van Assche
Date: Wed Sep 04 2019 - 12:09:18 EST


On 8/30/19 2:13 PM, Qian Cai wrote:
https://raw.githubusercontent.com/cailca/linux-mm/master/powerpc.config

Once in a while, booting an IBM POWER9 PowerNV system (8335-GTH) would generate
a warning in lockdep_register_key() at,

if (WARN_ON_ONCE(static_obj(key)))

because

key = 0xc0000000019ad118
&_stext = 0xc000000000000000
&_end = 0xc0000000049d0000

i.e., it will cause static_obj() returns 1.

(back from a trip)

Hi Qian,

Does this mean that on POWER9 it can happen that a dynamically allocated object has an address that falls between &_stext and &_end? Since I am not familiar with POWER9 nor have access to such a system, can you propose a patch?

Thanks,

Bart.