From: Waiman Long <longman@redhat.com>
To: Boqun Feng <boqun.feng@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>, Will Deacon <will@kernel.org>,
"Paul E. McKenney" <paulmck@kernel.org>,
Davidlohr Bueso <dave@stgolabs.net>,
linux-kernel@vger.kernel.org, Juri Lelli <juri.lelli@redhat.com>
Subject: Re: [PATCH 3/4] locking/ww_mutex: Treat ww_mutex_lock() like a trylock
Date: Wed, 17 Mar 2021 22:54:17 -0400 [thread overview]
Message-ID: <64af1d7b-6720-0ac1-4a55-bb0acb642c6f@redhat.com> (raw)
In-Reply-To: <YFK5yBIOTiCdFLNm@boqun-archlinux>
On 3/17/21 10:24 PM, Boqun Feng wrote:
> Hi Waiman,
>
> Just a question out of curiosity: how does this problem hide so long?
> ;-) Because IIUC, both locktorture and ww_mutex_lock have been there for
> a while, so why didn't we spot this earlier?
>
> I ask just to make sure we don't introduce the problem because of some
> subtle problems in lock(dep).
>
You have to explicitly specify ww_mutex in the locktorture module
parameter to run the test. ww_mutex is usually not the intended target
of testing as there aren't that many places that use it. Even if someone
run it, it probably is not on a debug kernel.
Our QA people try to run locktorture on ww_mutex and discover that.
Cheers,
Longman
next prev parent reply other threads:[~2021-03-18 2:55 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-16 15:31 [PATCH 0/4] locking/ww_mutex: Fix locktorture ww_mutex test problems Waiman Long
2021-03-16 15:31 ` [PATCH 1/4] locking/ww_mutex: Simplify use_ww_ctx & ww_ctx handling Waiman Long
2021-03-16 18:55 ` Davidlohr Bueso
2021-03-17 12:38 ` [tip: locking/urgent] " tip-bot2 for Waiman Long
2021-03-17 12:59 ` Peter Zijlstra
2021-03-17 13:43 ` Waiman Long
2021-03-17 13:55 ` Peter Zijlstra
2021-03-17 14:10 ` Waiman Long
2021-03-17 14:17 ` Peter Zijlstra
2021-03-17 14:33 ` Waiman Long
2021-03-16 15:31 ` [PATCH 2/4] locking/ww_mutex: Fix acquire/release imbalance in ww_acquire_init()/ww_acquire_fini() Waiman Long
2021-03-17 12:38 ` [tip: locking/urgent] " tip-bot2 for Waiman Long
2021-03-16 15:31 ` [PATCH 3/4] locking/ww_mutex: Treat ww_mutex_lock() like a trylock Waiman Long
2021-03-17 3:01 ` Davidlohr Bueso
2021-03-17 12:38 ` [tip: locking/urgent] " tip-bot2 for Waiman Long
2021-03-17 13:12 ` Peter Zijlstra
2021-03-17 13:31 ` Peter Zijlstra
2021-03-17 14:03 ` Waiman Long
2021-03-17 15:35 ` Waiman Long
2021-03-17 16:48 ` Peter Zijlstra
2021-03-17 17:40 ` Peter Zijlstra
2021-03-17 17:45 ` Peter Zijlstra
2021-03-17 18:32 ` Waiman Long
2021-03-17 19:58 ` Peter Zijlstra
2021-03-17 20:20 ` Waiman Long
2021-03-17 18:14 ` Waiman Long
2021-03-18 2:24 ` [PATCH 3/4] " Boqun Feng
2021-03-18 2:54 ` Waiman Long [this message]
2021-03-18 6:36 ` Boqun Feng
2021-03-16 15:31 ` [PATCH 4/4] locking/locktorture: Fix incorrect use of ww_acquire_ctx in ww_mutex test Waiman Long
2021-03-17 5:16 ` Davidlohr Bueso
2021-03-17 13:21 ` Waiman Long
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