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From: Richard Cochran <richardcochran@gmail.com>
To: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Rik van Riel <riel@redhat.com>,
	Jouni Malinen <jkmalinen@gmail.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	LKML <linux-kernel@vger.kernel.org>,
	Ingo Molnar <mingo@kernel.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Frederic Weisbecker <fweisbec@gmail.com>,
	Chris Mason <clm@fb.com>, Arjan van de Ven <arjan@infradead.org>,
	rt@linutronix.de, George Spelvin <linux@sciencehorizons.net>,
	Len Brown <lenb@kernel.org>,
	Josh Triplett <josh@joshtriplett.org>,
	Eric Dumazet <edumazet@google.com>
Subject: Re: [patch 4 14/22] timer: Switch to a non cascading wheel
Date: Tue, 16 Aug 2016 10:55:05 +0200	[thread overview]
Message-ID: <20160816085505.GB23077@localhost.localdomain> (raw)
In-Reply-To: <20160812191411.GA12616@linux.vnet.ibm.com>

On Fri, Aug 12, 2016 at 12:14:11PM -0700, Paul E. McKenney wrote:
> FWIW, I do appear to be seeing more lost wakeups on current mainline
> than on v4.7, but not enough of a difference to get a reliable bisction
> in reasonable time.

We are seeing reproducible hangs* when running Steven's
stress-cpu-hotplug under kvm.  This hang goes back to v4.7 at least.
I couldn't reproduce this with bare metal.  Thomas thought it was a
virtualization issue, not related to the hotplug rework.  He is away
until next week.  Maybe he knows more to say...

To reproduce, run 

   while [ 1 ]; do ./stress-cpu-hotplug ; done

and wait about 20 minutes (or longer).

Thanks,
Richard

* INFO: task cpuhp/7:49 blocked for more than 120 seconds

  reply	other threads:[~2016-08-16  8:55 UTC|newest]

Thread overview: 60+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-07-04  9:50 [patch 4 00/22] timer: Refactor the timer wheel Thomas Gleixner
2016-07-04  9:50 ` [patch 4 01/22] timer: Make pinned a timer property Thomas Gleixner
2016-07-07  8:39   ` [tip:timers/core] timers: Make 'pinned' " tip-bot for Thomas Gleixner
2016-07-04  9:50 ` [patch 4 02/22] x86/apic/uv: Initialize timer as pinned Thomas Gleixner
2016-07-07  8:40   ` [tip:timers/core] timers, x86/apic/uv: Initialize the UV heartbeat " tip-bot for Thomas Gleixner
2016-07-04  9:50 ` [patch 4 03/22] x86/mce: Initialize " Thomas Gleixner
2016-07-07  8:40   ` [tip:timers/core] timers, x86/mce: Initialize MCE restart " tip-bot for Thomas Gleixner
2016-07-04  9:50 ` [patch 4 04/22] cpufreq/powernv: Initialize " Thomas Gleixner
2016-07-07  8:41   ` [tip:timers/core] timers, cpufreq/powernv: Initialize the gpstate " tip-bot for Thomas Gleixner
2016-07-04  9:50 ` [patch 4 05/22] driver/net/ethernet/tile: Initialize " Thomas Gleixner
2016-07-07  8:41   ` [tip:timers/core] timers, driver/net/ethernet/tile: Initialize the egress " tip-bot for Thomas Gleixner
2016-07-04  9:50 ` [patch 4 06/22] drivers/tty/metag_da: Initialize " Thomas Gleixner
2016-07-07  8:42   ` [tip:timers/core] timers, drivers/tty/metag_da: Initialize the poll " tip-bot for Thomas Gleixner
2016-07-04  9:50 ` [patch 4 07/22] drivers/tty/mips_ejtag: Initialize " Thomas Gleixner
2016-07-07  8:42   ` [tip:timers/core] timers, drivers/tty/mips_ejtag: Initialize the poll " tip-bot for Thomas Gleixner
2016-07-04  9:50 ` [patch 4 08/22] net/ipv4/inet: Initialize timers " Thomas Gleixner
2016-07-07  8:43   ` [tip:timers/core] timers, net/ipv4/inet: Initialize connection request " tip-bot for Thomas Gleixner
2016-07-04  9:50 ` [patch 4 09/22] timer: Remove mod_timer_pinned Thomas Gleixner
2016-07-07  8:43   ` [tip:timers/core] timers: Remove the deprecated mod_timer_pinned() API tip-bot for Thomas Gleixner
2016-07-04  9:50 ` [patch 4 10/22] signal: Use hrtimer for sigtimedwait Thomas Gleixner
2016-07-07  8:43   ` [tip:timers/core] signals: Use hrtimer for sigtimedwait() tip-bot for Thomas Gleixner
2016-07-04  9:50 ` [patch 4 11/22] hlist: Add hlist_is_singular_node() helper Thomas Gleixner
2016-07-07  8:44   ` [tip:timers/core] " tip-bot for Thomas Gleixner
2016-07-04  9:50 ` [patch 4 12/22] timer: Give a few structs and members proper names Thomas Gleixner
2016-07-07  8:44   ` [tip:timers/core] timers: " tip-bot for Thomas Gleixner
2016-07-04  9:50 ` [patch 4 13/22] timer: Reduce the CPU index space to 256k Thomas Gleixner
2016-07-07  8:45   ` [tip:timers/core] timers: " tip-bot for Thomas Gleixner
2016-07-04  9:50 ` [patch 4 14/22] timer: Switch to a non cascading wheel Thomas Gleixner
2016-07-07  8:45   ` [tip:timers/core] timers: Switch to a non-cascading wheel tip-bot for Thomas Gleixner
2016-08-11 15:21   ` [patch 4 14/22] timer: Switch to a non cascading wheel Jouni Malinen
2016-08-11 20:25     ` [PREEMPT-RT] " rcochran
2016-08-13  9:12       ` Jouni Malinen
2016-08-16  9:46         ` Richard Cochran
2016-08-16 14:35           ` Eric Dumazet
2016-08-17  9:05           ` Jouni Malinen
2016-08-17  9:23             ` rcochran
2016-08-12 17:50     ` Rik van Riel
2016-08-12 19:14       ` Paul E. McKenney
2016-08-16  8:55         ` Richard Cochran [this message]
2016-08-16  7:57       ` Richard Cochran
2016-07-04  9:50 ` [patch 4 15/22] timer: Remove slack leftovers Thomas Gleixner
2016-07-07  8:46   ` [tip:timers/core] timers: Remove set_timer_slack() leftovers tip-bot for Thomas Gleixner
2016-07-22 11:31   ` [patch 4 15/22] timer: Remove slack leftovers Jason A. Donenfeld
2016-07-22 13:04     ` Thomas Gleixner
2016-07-22 15:18       ` Jason A. Donenfeld
2016-07-22 22:54         ` Jason A. Donenfeld
2016-07-04  9:50 ` [patch 4 16/22] timer: Move __run_timers() function Thomas Gleixner
2016-07-07  8:46   ` [tip:timers/core] timers: " tip-bot for Anna-Maria Gleixner
2016-07-04  9:50 ` [patch 4 17/22] timer: Optimize collect timers for NOHZ Thomas Gleixner
2016-07-07  8:47   ` [tip:timers/core] timers: Optimize collect_expired_timers() " tip-bot for Anna-Maria Gleixner
2016-07-04  9:50 ` [patch 4 18/22] tick/sched: Remove pointless empty function Thomas Gleixner
2016-07-07  8:47   ` [tip:timers/core] timers/nohz: Remove pointless tick_nohz_kick_tick() function tip-bot for Thomas Gleixner
2016-07-04  9:50 ` [patch 4 19/22] timer: Forward wheel clock whenever possible Thomas Gleixner
2016-07-07  8:48   ` [tip:timers/core] timers: Forward the " tip-bot for Thomas Gleixner
2016-07-04  9:50 ` [patch 4 20/22] timer: Only wake softirq if necessary Thomas Gleixner
2016-07-07  8:48   ` [tip:timers/core] timers: " tip-bot for Thomas Gleixner
2016-07-04  9:50 ` [patch 4 21/22] timer: Split out index calculation Thomas Gleixner
2016-07-07  8:48   ` [tip:timers/core] timers: " tip-bot for Anna-Maria Gleixner
2016-07-04  9:50 ` [patch 4 22/22] timer: Optimization for same expiry time in mod_timer() Thomas Gleixner
2016-07-07  8:49   ` [tip:timers/core] timers: Implement optimization " tip-bot for Anna-Maria Gleixner

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