Re: [mm, oom_adj] 9954f89181: INFO: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected ]

From: Michal Hocko
Date: Tue May 31 2016 - 03:55:53 EST


On Tue 31-05-16 04:03:35, kernel test robot wrote:
>
>
> FYI, we noticed the following commit:
>
> https://github.com/0day-ci/linux Michal-Hocko/Handle-oom-bypass-more-gracefully/20160530-210927
> commit 9954f891814d3f23e10036d2b6404cc80aaa461b ("mm, oom_adj: make sure processes sharing mm have same view of oom_score_adj")

JFTR this patch the underlying code has changed and sighand lock has
been removed. See the current state in
attempts/process-share-mm-oom-sanitization branch at
git://git.kernel.org/pub/scm/linux/kernel/git/mhocko/mm.git

> (md-udevd)/256 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire:
> (md-udevd)/256 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire:
> ( (&(&p->alloc_lock)->rlock&(&p->alloc_lock)->rlock){+.+...}){+.+...}, at: , at: [<ffffffff811d1008>] find_lock_task_mm+0x98/0x1b0
> [<ffffffff811d1008>] find_lock_task_mm+0x98/0x1b0
--
Michal Hocko
SUSE Labs