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From: Frederic Weisbecker <frederic@kernel.org>
To: Pingfan Liu <kernelfans@gmail.com>
Cc: paulmck@kernel.org, rcu@vger.kernel.org,
	David Woodhouse <dwmw@amazon.co.uk>,
	Neeraj Upadhyay <quic_neeraju@quicinc.com>,
	Josh Triplett <josh@joshtriplett.org>,
	Steven Rostedt <rostedt@goodmis.org>,
	Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
	Lai Jiangshan <jiangshanlai@gmail.com>,
	Joel Fernandes <joel@joelfernandes.org>,
	"Jason A. Donenfeld" <Jason@zx2c4.com>
Subject: Re: [PATCHv2 3/3] rcu: coordinate tick dependency during concurrent offlining
Date: Sun, 2 Oct 2022 17:08:58 +0200	[thread overview]
Message-ID: <20221002150858.GA292620@lothringen> (raw)
In-Reply-To: <CAFgQCTu75NPFM8L6a8-bgAzwzNtEdAV+DkXc7ssu6arf3o-o-A@mail.gmail.com>

On Sun, Oct 02, 2022 at 09:29:59PM +0800, Pingfan Liu wrote:
> On Fri, Sep 30, 2022 at 11:45 PM Paul E. McKenney <paulmck@kernel.org> wrote:
> >
> [...]
> > > > I have managed to grasp three two-socket machine, each has 256 cpus.
> > > > The test has run about 7 hours till now without any problem by the following command:
> > > > tools/testing/selftests/rcutorture/bin/kvm-remote.sh "sys1 sys2 sys3" \
> > > > --duration 45h --cpus 256 --bootargs "rcutorture.onoff_interval=200 rcutorture.onoff_holdoff=30" --configs "96*TREE04"
> > > >
> > > > It seems promising.
> > > >
> > >
> > > The test is against v6.0-rc7 kernel, and only with 96926686deab ("rcu:
> > > Make CPU-hotplug removal operations enable tick") reverted. It is
> > > close to the end, but unfortunately it fails.
> > > Quote from remote-log
> > > "
> > > TREE04.57 ------- 4410955 GPs (27.2281/s) [rcu: g36045577 f0x0
> > > total-gps=9011687] n_max_cbs: 4111392
> > > TREE04.58 ------- 4368391 GPs (26.9654/s) [rcu: g35630093 f0x0
> > > total-gps=8907816] n_max_cbs: 2411104
> > > TREE04.59 ------- 800516 GPs (4.94146/s) n_max_cbs: 3634471
> > > QEMU killed
> > > TREE04.59 no success message, 10547 successful version messages
> > > ^[[033mWARNING: ^[[mTREE04.59 GP HANG at 800516 torture stat 1925
> > > ^[[033mWARNING: ^[[mAssertion failure in
> > > /home/linux/tools/testing/selftests/rcutorture/res/2022.09.26-23.33.34-remote/TREE04.59/console.log
> > > TREE04.59
> > > ^[[033mWARNING: ^[[mSummary: Call Traces: 1 Stalls: 8615
> > > TREE04.6 ------- 4348443 GPs (26.8422/s) [rcu: g35341129 f0x0
> > > total-gps=8835575] n_max_cbs: 2329432
> >
> > First, thank you for running this!
> >
> > This is not the typical failure that we were seeing, which would show
> > up as a 2.199.0-second RCU CPU stall during which time there would be
> > no console messages.
> >
> > But please do let me know how continuing tests go!
> >
> 
> This time, the same test environment except against v6.0-rc7 mainline,
> also encountered the not typical failure.

Interesting, I'm trying to reproduce...

Thanks!

  reply	other threads:[~2022-10-02 15:09 UTC|newest]

Thread overview: 61+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-09-15  5:58 [PATCHv2 0/3] rcu: Enhance the capability to cope with concurrent cpu offlining/onlining Pingfan Liu
2022-09-15  5:58 ` [PATCHv2 1/3] rcu: Keep qsmaskinitnext fresh when rcutree_online_cpu() Pingfan Liu
2022-09-15  6:11   ` Pingfan Liu
2022-09-16 14:52   ` Frederic Weisbecker
2022-09-19 10:24     ` Pingfan Liu
2022-09-19 10:51       ` Frederic Weisbecker
2022-09-20  3:45         ` Pingfan Liu
2022-09-20  9:23           ` Frederic Weisbecker
2022-10-01  2:26             ` Joel Fernandes
2022-10-02 12:34               ` Pingfan Liu
2022-10-02 15:52                 ` Joel Fernandes
2022-09-20 10:31   ` Frederic Weisbecker
2022-09-21 11:56     ` Pingfan Liu
2022-09-15  5:58 ` [PATCHv2 2/3] rcu: Resort to cpu_dying_mask for affinity when offlining Pingfan Liu
2022-09-16 14:23   ` Frederic Weisbecker
2022-09-19  4:33     ` Pingfan Liu
2022-09-19 10:34       ` Frederic Weisbecker
2022-09-20  3:16         ` Pingfan Liu
2022-09-20  9:00           ` Frederic Weisbecker
2022-09-20  9:38   ` Frederic Weisbecker
2022-09-21 11:48     ` Pingfan Liu
2022-09-15  5:58 ` [PATCHv2 3/3] rcu: coordinate tick dependency during concurrent offlining Pingfan Liu
2022-09-16 13:42   ` Frederic Weisbecker
2022-09-20  7:26     ` Pingfan Liu
2022-09-20  9:46       ` Frederic Weisbecker
2022-09-20 19:13         ` Paul E. McKenney
2022-09-22  9:29           ` Pingfan Liu
2022-09-22 13:54             ` Paul E. McKenney
2022-09-23 22:13               ` Frederic Weisbecker
2022-09-26  6:34               ` Pingfan Liu
2022-09-26 22:23                 ` Paul E. McKenney
2022-09-27  9:59                   ` Pingfan Liu
2022-09-29  8:19                     ` Pingfan Liu
2022-09-29  8:20                       ` Pingfan Liu
2022-09-30 13:04                         ` Joel Fernandes
2022-10-02 14:06                           ` Pingfan Liu
2022-10-02 16:11                             ` Joel Fernandes
2022-10-02 16:24                               ` Paul E. McKenney
2022-10-02 16:30                                 ` Joel Fernandes
2022-10-02 16:57                                   ` Paul E. McKenney
2022-10-02 16:59                                     ` Joel Fernandes
2022-09-30 15:44                       ` Paul E. McKenney
2022-10-02 13:29                         ` Pingfan Liu
2022-10-02 15:08                           ` Frederic Weisbecker [this message]
2022-10-02 16:20                             ` Paul E. McKenney
2022-10-02 16:20                           ` Paul E. McKenney
     [not found]                             ` <CAFgQCTtgLfc0NeYqyWk4Ew-pA9rMREjRjWSnQhYLv-V5117s9Q@mail.gmail.com>
2022-10-27 17:46                               ` Paul E. McKenney
2022-10-31  3:24                                 ` Pingfan Liu
2022-11-03 16:51                                   ` Paul E. McKenney
2022-11-07 16:07                                     ` Paul E. McKenney
2022-11-09 18:55                                       ` Joel Fernandes
2022-11-18 12:08                                         ` Pingfan Liu
2022-11-18 23:30                                           ` Paul E. McKenney
2022-11-21  3:48                                             ` Pingfan Liu
2022-11-21 17:14                                               ` Paul E. McKenney
2022-11-17 14:39                                       ` Frederic Weisbecker
2022-11-18  1:45                                         ` Pingfan Liu
     [not found]                             ` <CAFgQCTtNetv7v_Law=abPtngC8Gv6OGcGz9M_wWMxz_GAEWDUQ@mail.gmail.com>
2022-10-27 18:13                               ` Paul E. McKenney
2022-10-31  2:10                                 ` Pingfan Liu
2022-09-26 16:13   ` Joel Fernandes
2022-09-27  9:42     ` Pingfan Liu

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