From: Waiman Long <llong@redhat.com>
To: Xiongwei Song <sxwjean@me.com>,
peterz@infradead.org, mingo@redhat.com, will@kernel.org,
boqun.feng@gmail.com
Cc: linux-kernel@vger.kernel.org, Xiongwei Song <sxwjean@gmail.com>
Subject: Re: [RFC PATCH v1 1/3] locking/lockdep: Fix false warning of check_wait_context()
Date: Sun, 11 Jul 2021 12:43:11 -0400 [thread overview]
Message-ID: <07878d21-fa4d-fbf5-a292-b71c48847a5e@redhat.com> (raw)
In-Reply-To: <20210711141430.896595-1-sxwjean@me.com>
On 7/11/21 10:14 AM, Xiongwei Song wrote:
> From: Xiongwei Song <sxwjean@gmail.com>
>
> We now always get a "Invalid wait context" warning with
> CONFIG_PROVE_RAW_LOCK_NESTING=y, see the full warning below:
>
> [ 0.705900] =============================
> [ 0.706002] [ BUG: Invalid wait context ]
> [ 0.706180] 5.13.0+ #4 Not tainted
> [ 0.706349] -----------------------------
I believe the purpose of CONFIG_PROVE_RAW_LOCK_NESTING is experimental
and it is turned off by default. Turning it on can cause problem as
shown in your lockdep splat. Limiting it to just PREEMPT_RT will defeat
its purpose to find potential spinlock nesting problem in non-PREEMPT_RT
kernel. The point is to fix the issue found, not hiding it from appearing.
Cheers,
Longman
next prev parent reply other threads:[~2021-07-11 16:43 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-11 14:14 [RFC PATCH v1 1/3] locking/lockdep: Fix false warning of check_wait_context() Xiongwei Song
2021-07-11 14:14 ` [RFC PATCH v1 2/3] locking/lockdep: Unify the return values " Xiongwei Song
2021-07-11 15:19 ` Waiman Long
2021-07-12 7:48 ` Xiongwei Song
2021-07-23 2:57 ` [locking/lockdep] e0a77a7a5a: WARNING:bad_unlock_balance_detected kernel test robot
2021-07-11 14:14 ` [PATCH v1 3/3] locking/lockdep,doc: Correct the max number of lock classes Xiongwei Song
2021-07-11 15:22 ` Waiman Long
2021-07-12 7:49 ` Xiongwei Song
2021-07-11 16:43 ` Waiman Long [this message]
2021-07-12 8:18 ` [RFC PATCH v1 1/3] locking/lockdep: Fix false warning of check_wait_context() Xiongwei Song
2021-07-12 8:50 ` Boqun Feng
2021-07-12 9:21 ` Xiongwei Song
2021-07-12 13:04 ` Waiman Long
2021-07-12 15:03 ` Xiongwei Song
2021-07-13 2:29 ` Xiongwei Song
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