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From: "H. Peter Anvin" <hpa@zytor.com>
To: Ingo Molnar <mingo@kernel.org>
Cc: Russ Anderson <rja@sgi.com>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Robin Holt <holt@sgi.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Shawn Guo <shawn.guo@linaro.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>,
	the arch/x86 maintainers <x86@kernel.org>
Subject: Re: [PATCH] Do not force shutdown/reboot to boot cpu.
Date: Wed, 10 Apr 2013 10:58:06 -0700	[thread overview]
Message-ID: <5165A82E.8000609@zytor.com> (raw)
In-Reply-To: <20130410165934.GB21951@gmail.com>

On 04/10/2013 09:59 AM, Ingo Molnar wrote:
> 
> 4 minutes bootup is 240 seconds, with 1024 CPUs that's about 240 msecs per CPU.
> 
> That sounds a lot, given that unlike bootup there's not much real work to be done 
> during shutdown - we don't initialize anything, etc.
> 
> Maybe much of those 240 msecs are spent in some stupid udelay loop or so, which 
> could be made parallel?
> 

I wonder if it isn't calling stop_machine() 1024 times, each time
rendezvousing all the still-active CPUs.

	-hpa



  parent reply	other threads:[~2013-04-10 17:58 UTC|newest]

Thread overview: 45+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-04-03 19:37 [PATCH] Do not force shutdown/reboot to boot cpu Robin Holt
2013-04-08 15:57 ` Ingo Molnar
2013-04-08 16:11   ` H. Peter Anvin
2013-04-08 16:59     ` Robin Holt
2013-04-10 11:16       ` Ingo Molnar
2013-04-10 14:01         ` Robin Holt
2013-04-10 15:10         ` Linus Torvalds
2013-04-10 15:29           ` Russ Anderson
2013-04-10 16:59             ` Ingo Molnar
2013-04-10 17:14               ` Robin Holt
2013-04-10 17:22                 ` Ingo Molnar
2013-04-10 17:55                   ` Robin Holt
2013-04-10 19:00                     ` Robin Holt
2013-04-11  8:57                       ` Ingo Molnar
2013-04-11 11:34                         ` Robin Holt
2013-04-11 12:00                           ` Ingo Molnar
2013-04-11 12:03                             ` Robin Holt
2013-04-11 12:08                               ` Robin Holt
2013-04-11 12:14                                 ` Ingo Molnar
2013-04-10 17:58               ` H. Peter Anvin [this message]
2013-04-10 23:02               ` Russ Anderson
2013-04-10 22:29             ` Russ Anderson
2013-04-11  5:31           ` Paul Mackerras
2013-04-11 12:45             ` Bulk CPU Hotplug (Was Re: [PATCH] Do not force shutdown/reboot to boot cpu.) Srivatsa S. Bhat
2013-04-11 13:48               ` Robin Holt
2013-04-12  5:37                 ` Ingo Molnar
2013-04-12  6:09                   ` Srivatsa S. Bhat
2013-04-12  9:31                     ` Robin Holt
2013-04-12 10:01                       ` Robin Holt
2013-04-13 16:30                       ` Oleg Nesterov
2013-04-15 16:04                         ` Robin Holt
2013-04-15 16:09                           ` Oleg Nesterov
2013-04-15 16:10                           ` Robin Holt
2013-04-13 17:01                       ` Srivatsa S. Bhat
2013-04-15 10:16                       ` Ingo Molnar
2013-04-15 12:02                         ` Robin Holt
2013-04-15 15:59                           ` Robin Holt
2013-04-16  9:40                             ` Ingo Molnar
2013-04-11 14:23               ` Russ Anderson
2013-04-11 14:45                 ` Srivatsa S. Bhat
2013-04-11 20:08                   ` Russ Anderson
2013-04-11 20:17                     ` Srivatsa S. Bhat
2013-04-11 21:08                     ` Robin Holt
2013-04-08 16:54   ` [PATCH] Do not force shutdown/reboot to boot cpu Robin Holt
2013-04-08 17:07   ` Russ Anderson

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