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From: Eric Dumazet <edumazet@google.com>
Date: Wed, 23 Nov 2016 12:03:28 -0800
Message-ID: <CANn89iJXeNFgmy8YgSSnuNrekev-FgoyJ1GqOdFgM48wfpbr5Q@mail.gmail.com>
Subject: Re: Regression: Failed boots bisected to 4cd13c21b207 "softirq: Let
 ksoftirqd do its job"
To: Brian Starkey <brian.starkey@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
        LKML <linux-kernel@vger.kernel.org>,
        Peter Zijlstra <peterz@infradead.org>, Ingo Molnar <mingo@kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Alexander Potapenko <glider@google.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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On Wed, Nov 23, 2016 at 10:21 AM, Brian Starkey <brian.starkey@arm.com> wrote:

> This patch didn't help.
>
> I did get some new traces though - I've attached the diff for the
> trace_printks I added.
>
> Before 4cd13c21b207:
> https://drive.google.com/open?id=0B8siaK6ZjvEwcEtOeFQzTmY0Nnc
> After 4cd13c21b207:
> https://drive.google.com/open?id=0B8siaK6ZjvEwZnQ4MVg1d3d1Tm8
>
> It looks like the difference is that after 4cd13c21b207 the RX softirq
> isn't running, and RX interrupts don't call softirq_raise anymore -
> presumably because there's one pending, but I didn't have time to
> track that down to a code-path.
>
> Cheers,
> -Brian
>

Hi Brian

Looks like netif_rx() drops the incoming packets then ?

Maybe netif_running() is not happy :(

Could you trace netif_rx() return value (NET_RX_SUCCESS or NET_RX_DROP)

Thanks !