From: Thomas Gleixner <tglx@linutronix.de>
To: "Luck, Tony" <tony.luck@intel.com>
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: Sat, 12 Mar 2016 09:27:28 +0100 (CET) [thread overview]
Message-ID: <alpine.DEB.2.11.1603120926310.3657@nanos> (raw)
In-Reply-To: <20160311223357.GA2544@intel.com>
On Fri, 11 Mar 2016, Luck, Tony wrote:
> 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.
Yes. I noticed that as well. No idea where we waste all that time. I've put
that on the todo list of our ongoing hotplug refactoring work.
Thanks,
tglx
next prev parent reply other threads:[~2016-03-12 8:29 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-11 20:19 Thomas Gleixner
2016-03-11 22:33 ` Luck, Tony
2016-03-12 8:27 ` Thomas Gleixner [this message]
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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