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From: Florian Westphal <fw@strlen.de>
To: Peter Marczis <peter.marczis@greenwavesystems.com>
Cc: netfilter-devel@vger.kernel.org
Subject: Re: conntrack (possibly) hangs on our ARM CPU in case we delete 5k+ connections as fast as possible
Date: Tue, 14 Mar 2017 11:33:00 +0100	[thread overview]
Message-ID: <20170314103300.GA8738@breakpoint.cc> (raw)
In-Reply-To: <CAMm+moMPBxBmrnNuwK6tK_Bu2oKaxOMj=BK=DtpYT_YStO9P7A@mail.gmail.com>

Peter Marczis <peter.marczis@greenwavesystems.com> wrote:
> Hello developers,
> I'm seeking some help to debug and solve one of my issues.
> 
> We observed that if we create 30k connections, everything works as
> expected, but when we start to disconnect them,
> conntrack (well not confirmed yet fully) makes the kernel side busy,
> and looks like no scheduling happens.

What do you mean by 'disconnect'?  conntrack -F ?

My wild guss is you need to backport

commit d93c6258ee4255749c10012c50a31c08f4e9fb16
netfilter: conntrack: resched in nf_ct_iterate_cleanup

> The whole thing works as expected, the only problem it makes our
> processes and well everything on user side hanging for a couple of
> seconds 10-30s,
> which of course triggers our HW Watchdog, and we end up in a reboot.

You could try

CONFIG_LOCKUP_DETECTOR=y
CONFIG_HARDLOCKUP_DETECTOR=y


  reply	other threads:[~2017-03-14 10:33 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-03-14  9:56 conntrack (possibly) hangs on our ARM CPU in case we delete 5k+ connections as fast as possible Peter Marczis
2017-03-14 10:33 ` Florian Westphal [this message]
2017-03-14 11:11   ` Peter Marczis
2017-03-14 11:20     ` Florian Westphal
2017-03-16 10:58       ` Peter Marczis

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