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From: linux@arm.linux.org.uk (Russell King - ARM Linux)
To: linux-arm-kernel@lists.infradead.org
Subject: [RFC] Make SMP secondary CPU up more resilient to failure.
Date: Sat, 18 Dec 2010 20:04:43 +0000	[thread overview]
Message-ID: <20101218200443.GM9937@n2100.arm.linux.org.uk> (raw)
In-Reply-To: <AANLkTimG8yuCMOJPz9-ANi_2hf7E2HPYPy9sWaxVPXmE@mail.gmail.com>

On Sat, Dec 18, 2010 at 06:10:49AM -0600, Andrei Warkentin wrote:
> Definitely. This would be exactly the right place to place any holding
> logic...

FYI, I've managed to get some timing figures out of my Versatile
Express platform.  It takes about 100us for a CPU to come online via
hotplug, and a further 222ms to run the calibration before marking the
CPU online.

That leaves a margin of about 750ms before the timeout in the generic code
fires.

CPU requesting hotplug, times in ns:
SMP: Start: 0
SMP: Booting: 750
SMP: Cross call: 3500
SMP: Pen released: 41167
SMP: Unlock: 42417
SMP: Boot returned: 43250

CPU being brought online, referenced to "SMP: Start" above, times in ns.
SMP: Sec: restart: 3834
SMP: Sec: up: 5334
SMP: Sec: enter: 30667
SMP: Sec: pen write: 38917
SMP: Sec: pen done: 41417
SMP: Sec: exit: 42750
SMP: Sec: calibrate: 91834
SMP: Sec: online: 222054375

  reply	other threads:[~2010-12-18 20:04 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-12-15 23:45 [RFC] Make SMP secondary CPU up more resilient to failure Andrei Warkentin
2010-12-16 11:34 ` Russell King - ARM Linux
2010-12-16 23:09   ` Andrei Warkentin
2010-12-16 23:28     ` Russell King - ARM Linux
2010-12-17 20:52       ` Andrei Warkentin
2010-12-17 23:14         ` Russell King - ARM Linux
2010-12-17 23:45           ` Andrei Warkentin
2010-12-18  0:08             ` Russell King - ARM Linux
2010-12-18  0:36               ` Russell King - ARM Linux
2010-12-18  7:17               ` Andrei Warkentin
2010-12-18 12:01                 ` Russell King - ARM Linux
2010-12-18 12:10                   ` Andrei Warkentin
2010-12-18 20:04                     ` Russell King - ARM Linux [this message]
2010-12-21 21:53                       ` Andrei Warkentin
2010-12-24 17:38                         ` Russell King - ARM Linux
2011-01-13 10:19                           ` Andrei Warkentin
2011-01-13 11:14                             ` Russell King - ARM Linux
2011-01-13 22:03                               ` Andrei Warkentin
2010-12-17  0:11     ` murali at embeddedwireless.com
2010-12-18  9:58     ` Russell King - ARM Linux
2010-12-18 11:54       ` Andrei Warkentin
2010-12-18 12:19         ` Russell King - ARM Linux

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