From: Ingo Molnar <mingo@kernel.org>
To: lkp@lists.01.org
Subject: Re: [lockdep] b09be676e0 BUG: unable to handle kernel NULL pointer dereference at 000001f2
Date: Wed, 04 Oct 2017 12:31:19 +0200 [thread overview]
Message-ID: <20171004103119.sedmwqcfwu3ze5od@gmail.com> (raw)
In-Reply-To: <20171004092052.ioixdexrsbbwvetr@hirez.programming.kicks-ass.net>
[-- Attachment #1: Type: text/plain, Size: 617 bytes --]
* Peter Zijlstra <peterz@infradead.org> wrote:
> On Tue, Oct 03, 2017 at 07:18:24PM +0200, Ingo Molnar wrote:
> > Yes, I'll do that tomorrow. I was always a bit unhappy about cross-release,
> > because it breaks the 'owner task owns the lock' model.
>
> Still, you can get real deadlocks with completions...
>
> > Plus I don't think we found that many real bugs with it
>
> Every bug found is one less bug. It did find a few.
Certainly, but the total work saved by finding bugs should be balanced against the
additional fragility of lockdep and the ongoing maintenance cost.
Thanks,
Ingo
WARNING: multiple messages have this Message-ID (diff)
From: Ingo Molnar <mingo@kernel.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Fengguang Wu <fengguang.wu@intel.com>,
Byungchul Park <byungchul.park@lge.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
LKP <lkp@01.org>, Josh Poimboeuf <jpoimboe@redhat.com>
Subject: Re: [lockdep] b09be676e0 BUG: unable to handle kernel NULL pointer dereference at 000001f2
Date: Wed, 4 Oct 2017 12:31:19 +0200 [thread overview]
Message-ID: <20171004103119.sedmwqcfwu3ze5od@gmail.com> (raw)
In-Reply-To: <20171004092052.ioixdexrsbbwvetr@hirez.programming.kicks-ass.net>
* Peter Zijlstra <peterz@infradead.org> wrote:
> On Tue, Oct 03, 2017 at 07:18:24PM +0200, Ingo Molnar wrote:
> > Yes, I'll do that tomorrow. I was always a bit unhappy about cross-release,
> > because it breaks the 'owner task owns the lock' model.
>
> Still, you can get real deadlocks with completions...
>
> > Plus I don't think we found that many real bugs with it
>
> Every bug found is one less bug. It did find a few.
Certainly, but the total work saved by finding bugs should be balanced against the
additional fragility of lockdep and the ongoing maintenance cost.
Thanks,
Ingo
next prev parent reply other threads:[~2017-10-04 10:31 UTC|newest]
Thread overview: 102+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-03 14:06 [lockdep] b09be676e0 BUG: unable to handle kernel NULL pointer dereference at 000001f2 Fengguang Wu
2017-10-03 14:06 ` Fengguang Wu
2017-10-03 14:31 ` Josh Poimboeuf
2017-10-03 14:31 ` Josh Poimboeuf
2017-10-03 14:41 ` Josh Poimboeuf
2017-10-03 14:41 ` Josh Poimboeuf
2017-10-03 15:05 ` Josh Poimboeuf
2017-10-03 15:05 ` Josh Poimboeuf
2017-10-03 16:28 ` Josh Poimboeuf
2017-10-03 16:28 ` Josh Poimboeuf
2017-10-03 17:34 ` Josh Poimboeuf
2017-10-03 17:34 ` Josh Poimboeuf
2017-10-03 21:44 ` Tetsuo Handa
2017-10-03 21:44 ` Tetsuo Handa
2017-10-04 21:06 ` Josh Poimboeuf
2017-10-04 21:06 ` Josh Poimboeuf
2017-10-04 21:30 ` Linus Torvalds
2017-10-04 21:30 ` Linus Torvalds
2017-10-04 22:15 ` Josh Poimboeuf
2017-10-04 22:15 ` Josh Poimboeuf
2017-10-04 22:40 ` Josh Poimboeuf
2017-10-04 22:40 ` Josh Poimboeuf
2017-10-05 11:02 ` Tetsuo Handa
2017-10-05 11:02 ` Tetsuo Handa
2017-10-05 13:57 ` Josh Poimboeuf
2017-10-05 13:57 ` Josh Poimboeuf
2017-10-04 8:34 ` Peter Zijlstra
2017-10-04 8:34 ` Peter Zijlstra
2017-10-10 5:57 ` Byungchul Park
2017-10-10 5:57 ` Byungchul Park
2017-10-03 16:54 ` Linus Torvalds
2017-10-03 16:54 ` Linus Torvalds
2017-10-03 16:57 ` Linus Torvalds
2017-10-03 16:57 ` Linus Torvalds
2017-10-10 5:48 ` Byungchul Park
2017-10-10 5:48 ` Byungchul Park
2017-10-10 16:22 ` Linus Torvalds
2017-10-10 16:22 ` Linus Torvalds
2017-10-10 16:56 ` Linus Torvalds
2017-10-10 16:56 ` Linus Torvalds
2017-10-10 18:14 ` Peter Zijlstra
2017-10-10 18:14 ` Peter Zijlstra
2017-10-10 18:38 ` Linus Torvalds
2017-10-10 18:38 ` Linus Torvalds
2017-10-11 1:14 ` Byungchul Park
2017-10-11 1:14 ` Byungchul Park
2017-10-11 2:36 ` Byungchul Park
2017-10-11 2:36 ` Byungchul Park
2017-10-11 0:56 ` Byungchul Park
2017-10-11 0:56 ` Byungchul Park
2017-10-11 1:02 ` Byungchul Park
2017-10-11 1:02 ` Byungchul Park
2017-10-12 1:15 ` Byungchul Park
2017-10-12 1:15 ` Byungchul Park
2017-10-03 17:18 ` Ingo Molnar
2017-10-03 17:18 ` Ingo Molnar
2017-10-04 9:20 ` Peter Zijlstra
2017-10-04 9:20 ` Peter Zijlstra
2017-10-04 10:31 ` Ingo Molnar [this message]
2017-10-04 10:31 ` Ingo Molnar
2017-10-04 14:15 ` Josh Poimboeuf
2017-10-04 14:15 ` Josh Poimboeuf
2017-10-10 5:30 ` Byungchul Park
2017-10-10 5:30 ` Byungchul Park
2017-10-05 13:01 ` Josh Poimboeuf
2017-10-05 13:01 ` Josh Poimboeuf
2017-10-05 14:54 ` Josh Poimboeuf
2017-10-05 14:54 ` Josh Poimboeuf
2017-10-09 10:50 ` Peter Zijlstra
2017-10-09 10:50 ` Peter Zijlstra
2017-10-09 12:21 ` Fengguang Wu
2017-10-09 12:21 ` Fengguang Wu
2017-10-09 12:54 ` Peter Zijlstra
2017-10-09 12:54 ` Peter Zijlstra
2017-10-09 12:59 ` Fengguang Wu
2017-10-09 12:59 ` Fengguang Wu
2017-10-09 13:03 ` Josh Poimboeuf
2017-10-09 13:03 ` Josh Poimboeuf
2017-10-09 12:55 ` Fengguang Wu
2017-10-09 12:55 ` Fengguang Wu
2017-10-09 13:26 ` Josh Poimboeuf
2017-10-09 13:26 ` Josh Poimboeuf
2017-10-09 14:17 ` Fengguang Wu
2017-10-09 14:17 ` Fengguang Wu
2017-10-09 15:28 ` Peter Zijlstra
2017-10-09 15:28 ` Peter Zijlstra
2017-10-09 15:41 ` Fengguang Wu
2017-10-09 15:41 ` Fengguang Wu
2017-10-09 15:44 ` Peter Zijlstra
2017-10-09 15:44 ` Peter Zijlstra
2017-10-09 15:47 ` Fengguang Wu
2017-10-09 15:47 ` Fengguang Wu
2017-10-10 5:08 ` Byungchul Park
2017-10-10 5:08 ` Byungchul Park
2017-10-12 8:47 ` Peter Zijlstra
2017-10-12 8:47 ` Peter Zijlstra
2017-10-12 9:21 ` Fengguang Wu
2017-10-12 9:21 ` Fengguang Wu
2017-10-12 9:28 ` Fengguang Wu
2017-10-12 9:28 ` Fengguang Wu
2017-10-12 11:45 ` Peter Zijlstra
2017-10-12 11:45 ` Peter Zijlstra
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