From: Jason Gunthorpe <jgg@nvidia.com>
To: "Pearson, Robert B" <robert.pearson2@hpe.com>
Cc: Bob Pearson <rpearsonhpe@gmail.com>,
Bart Van Assche <bvanassche@acm.org>,
Guoqing Jiang <guoqing.jiang@linux.dev>,
"linux-rdma@vger.kernel.org" <linux-rdma@vger.kernel.org>
Subject: Re: Inconsistent lock state warning for rxe_poll_cq()
Date: Tue, 15 Feb 2022 13:01:38 -0400 [thread overview]
Message-ID: <20220215170138.GX4160@nvidia.com> (raw)
In-Reply-To: <PH7PR84MB14882185ED3BA2DEC460D894BC349@PH7PR84MB1488.NAMPRD84.PROD.OUTLOOK.COM>
On Tue, Feb 15, 2022 at 04:53:25PM +0000, Pearson, Robert B wrote:
> > > spinlock_irqsave()
> > > write_lock_bh()
> > > write_unlock_bh()
> > > spinunlock_irqrestore()
> >
> > > Which is illegal locking.
> >
> > > Jason
> >
> Jason, can you tell me what the problem is with this. I'm not fighting it just want to know.
I don't know the exact reason, judging from the code it looks like the
implementation of unlock_bh is allowed to assume hard irqs were not
blocked and unblock them - probably some micro-optimization.
I don't think there is a deadlock issue with the above because irqsave
is a superset of the _bh varient.
Jason
next prev parent reply other threads:[~2022-02-15 17:01 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-14 18:01 Inconsistent lock state warning for rxe_poll_cq() Bart Van Assche
2022-02-14 19:51 ` Bob Pearson
2022-02-14 19:55 ` Bart Van Assche
2022-02-14 20:25 ` Bob Pearson
2022-02-14 20:48 ` Bart Van Assche
2022-02-15 5:43 ` Bob Pearson
2022-02-15 12:16 ` Guoqing Jiang
2022-02-15 14:41 ` Jason Gunthorpe
2022-02-15 16:45 ` Pearson, Robert B
2022-02-15 16:48 ` Jason Gunthorpe
2022-02-15 16:53 ` Pearson, Robert B
2022-02-15 17:01 ` Jason Gunthorpe [this message]
2022-02-15 17:18 ` Haakon Bugge
2022-02-15 4:50 ` Guoqing Jiang
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