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From: "Luck, Tony" <tony.luck@intel.com>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: LKML <linux-kernel@vger.kernel.org>,
	Harry Junior <harryjr@outlook.fr>,
	x86@kernel.org, Peter Zijlstra <peterz@infradead.org>,
	Joe Lawrence <joe.lawrence@stratus.com>,
	Borislav Petkov <bp@alien8.de>
Subject: Re: [PATCH] x86/irq: Cure live lock in irq_force_complete_move()
Date: Fri, 11 Mar 2016 14:33:57 -0800	[thread overview]
Message-ID: <20160311223357.GA2544@intel.com> (raw)
In-Reply-To: <alpine.DEB.2.11.1603112048030.3657@nanos>

With this patch applied my system survives me doing
several rounds of:

# echo 0 | tee /sys/devices/system/cpu/cpu*/online
# echo 1 | tee /sys/devices/system/cpu/cpu*/online

whereas without the patch the first of those went to

[152455.129604] NMI watchdog: Watchdog detected hard LOCKUP on cpu 96
[152455.136943] Kernel panic - not syncing: Hard LOCKUP

I'm not sure we care to optimize the cpu offline path, but I'll note here
that taking all (but one) cpus offline took 52 seconds (for a hundred
and mumble logical cpus).  Bringing them all back is just 4 seconds.

Tested-by: Tony Luck <tony.luck@intel.com>

  reply	other threads:[~2016-03-11 22:34 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-03-11 20:19 [PATCH] x86/irq: Cure live lock in irq_force_complete_move() Thomas Gleixner
2016-03-11 22:33 ` Luck, Tony [this message]
2016-03-12  8:27   ` Thomas Gleixner
2016-03-12 10:58   ` Thomas Gleixner
2016-03-12 15:23 ` Ingo Molnar
2016-03-12 19:56   ` Thomas Gleixner

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