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Date:   Fri, 28 Jan 2022 09:07:04 +0100
From:   Marc Kleine-Budde <mkl@pengutronix.de>
To:     Oliver Hartkopp <socketcan@hartkopp.net>
Cc:     "Ziyang Xuan (William)" <william.xuanziyang@huawei.com>,
        davem@davemloft.net, kuba@kernel.org, linux-can@vger.kernel.org,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH net] can: isotp: isotp_rcv_cf(): fix so->rx race problem
Message-ID: <20220128080704.ns5fzbyn72wfoqmx@pengutronix.de>
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On 28.01.2022 08:56:19, Oliver Hartkopp wrote:
> I've seen the frame processing sometimes freezes for one second when
> stressing the isotp_rcv() from multiple sources. This finally freezes
> the entire softirq which is either not good and not needed as we only
> need to fix this race for stress tests - and not for real world usage
> that does not create this case.

Hmmm, this doesn't sound good. Can you test with LOCKDEP enabled?

>=20
> Therefore I created a V2 patch which uses the spin_trylock() to simply dr=
op
> the incomming frame in the race condition.
>=20
> https://lore.kernel.org/linux-can/20220128074327.52229-1-socketcan@hartko=
pp.net/T/
>=20
> Please take a look, if it also fixes the issue in your test setup.

regards,
Marc

--=20
Pengutronix e.K.                 | Marc Kleine-Budde           |
Embedded Linux                   | https://www.pengutronix.de  |
Vertretung West/Dortmund         | Phone: +49-231-2826-924     |
Amtsgericht Hildesheim, HRA 2686 | Fax:   +49-5121-206917-5555 |

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