From: Oliver Neukum <oneukum@suse.com>
To: Eric Dumazet <eric.dumazet@gmail.com>,
Marek Szyprowski <m.szyprowski@samsung.com>,
LKML <linux-kernel@vger.kernel.org>,
'Linux Samsung SOC' <linux-samsung-soc@vger.kernel.org>,
Linux USB Mailing List <linux-usb@vger.kernel.org>,
netdev@vger.kernel.org
Cc: Dean Jenkins <Dean_Jenkins@mentor.com>
Subject: Re: inconsistent lock state with usbnet/asix usb ethernet and xhci
Date: Tue, 27 Feb 2018 17:07:55 +0100 [thread overview]
Message-ID: <1519747675.2649.3.camel@suse.com> (raw)
In-Reply-To: <1519744400.7296.10.camel@gmail.com>
Am Dienstag, den 27.02.2018, 07:13 -0800 schrieb Eric Dumazet:
> On Tue, 2018-02-27 at 07:09 -0800, Eric Dumazet wrote:
> >
> >
> > Note that for this one, it seems we also could perform stats updates in
> > BH context, since skb is queued via defer_bh()
> >
> > But simplicity wins I guess.
>
> Thinking more about this, I am not sure we have any guarantee that TX
> and RX can not run on multiple cpus.
>
> Using an unique syncp is not going to be safe, even if we make lockdep
> happy enough with the local_irq save/restore.
Unfortunately you are right. It is not guaranteed for some hardware.
Regards
Oliver
WARNING: multiple messages have this Message-ID (diff)
From: Oliver Neukum <oneukum@suse.com>
To: Eric Dumazet <eric.dumazet@gmail.com>,
Marek Szyprowski <m.szyprowski@samsung.com>,
LKML <linux-kernel@vger.kernel.org>,
'Linux Samsung SOC' <linux-samsung-soc@vger.kernel.org>,
Linux USB Mailing List <linux-usb@vger.kernel.org>,
netdev@vger.kernel.org
Cc: Dean Jenkins <Dean_Jenkins@mentor.com>
Subject: inconsistent lock state with usbnet/asix usb ethernet and xhci
Date: Tue, 27 Feb 2018 17:07:55 +0100 [thread overview]
Message-ID: <1519747675.2649.3.camel@suse.com> (raw)
Am Dienstag, den 27.02.2018, 07:13 -0800 schrieb Eric Dumazet:
> On Tue, 2018-02-27 at 07:09 -0800, Eric Dumazet wrote:
> >
> >
> > Note that for this one, it seems we also could perform stats updates in
> > BH context, since skb is queued via defer_bh()
> >
> > But simplicity wins I guess.
>
> Thinking more about this, I am not sure we have any guarantee that TX
> and RX can not run on multiple cpus.
>
> Using an unique syncp is not going to be safe, even if we make lockdep
> happy enough with the local_irq save/restore.
Unfortunately you are right. It is not guaranteed for some hardware.
Regards
Oliver
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next prev parent reply other threads:[~2018-02-27 16:07 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CGME20180227072602eucas1p28dcdba711b3153820bd409d838cc63bd@eucas1p2.samsung.com>
2018-02-27 7:26 ` inconsistent lock state with usbnet/asix usb ethernet and xhci Marek Szyprowski
2018-02-27 10:37 ` Oliver Neukum
2018-02-27 10:59 ` Marek Szyprowski
2018-02-27 14:07 ` Eric Dumazet
2018-02-27 14:07 ` Eric Dumazet
2018-02-27 14:42 ` Marek Szyprowski
2018-02-27 14:42 ` Marek Szyprowski
2018-02-27 15:09 ` Eric Dumazet
2018-02-27 15:09 ` Eric Dumazet
2018-02-27 15:13 ` Eric Dumazet
2018-02-27 15:13 ` Eric Dumazet
2018-02-27 16:07 ` Oliver Neukum [this message]
2018-02-27 16:07 ` Oliver Neukum
2018-03-05 7:45 ` Marek Szyprowski
2018-03-05 7:45 ` Marek Szyprowski
2018-03-05 11:46 ` Oliver Neukum
2018-03-05 11:46 ` Oliver Neukum
2018-03-05 19:09 ` Eric Dumazet
2018-03-05 19:09 ` Eric Dumazet
2018-03-05 19:41 [net] net: usbnet: fix potential deadlock on 32bit hosts Eric Dumazet
2018-03-05 19:41 ` [PATCH net] " Eric Dumazet
-- strict thread matches above, loose matches on Subject: below --
2018-03-07 16:47 [net] " David Miller
2018-03-07 16:47 ` [PATCH net] " David Miller
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