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From:   Cong Wang <xiyou.wangcong@gmail.com>
Date:   Wed, 4 Mar 2020 15:19:59 -0800
Message-ID: <CAM_iQpVkyt5C2RG==jJSHumpY1o+M2H0nHRtMs6xp6_fpW3WMA@mail.gmail.com>
Subject: Re: BUG: MAX_LOCKDEP_CHAINS too low!
To:     Dmitry Vyukov <dvyukov@google.com>
Cc:     Taehee Yoo <ap420073@gmail.com>,
        Peter Zijlstra <peterz@infradead.org>,
        syzbot <syzbot+aaa6fa4949cc5d9b7b25@syzkaller.appspotmail.com>,
        Ingo Molnar <mingo@kernel.org>,
        Will Deacon <will.deacon@arm.com>,
        LKML <linux-kernel@vger.kernel.org>,
        syzkaller-bugs <syzkaller-bugs@googlegroups.com>,
        Thomas Gleixner <tglx@linutronix.de>
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On Wed, Mar 4, 2020 at 12:03 AM Dmitry Vyukov <dvyukov@google.com> wrote:
>
> On Sat, Jan 18, 2020 at 9:41 PM Cong Wang <xiyou.wangcong@gmail.com> wrote:
> >
> > On Thu, Jan 16, 2020 at 7:09 AM Taehee Yoo <ap420073@gmail.com> wrote:
> > > Yes, I fully agree with this.
> > > If we calculate the subclass for lock_nested() very well, I think we
> > > might use static lockdep key for addr_list_lock_key too. I think
> > > "dev->upper_level" and "dev->lower_level" might be used as subclass.
> > > These values are updated recursively in master/nomaster operation.
> >
> > Great! I will think about this too. At least I will remove the other keys
> > for net-next.
>
> Hi Cong,
>
> Was this done? This still harms testing of the whole kernel. Disabling
> LOCKDEP does not look good either...

Not yet, I have a half-done patch locally, will work on it to make it
complete for net-next.

Thanks for reminding me!