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From: robherring2@gmail.com (Rob Herring)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] ARM: smp: Introduce ARCH_HAS_COMMON_CORES_CLOCK to speed-up boot
Date: Thu, 20 Jan 2011 09:14:29 -0600	[thread overview]
Message-ID: <4D385155.4050301@gmail.com> (raw)
In-Reply-To: <1295516579-10225-1-git-send-email-santosh.shilimkar@ti.com>

On 01/20/2011 03:42 AM, Santosh Shilimkar wrote:
> On some architectures, secondary cores shares clock with primiary
> core and hence scale together. Hence secondary core lpj calibration
> is not necessary and can be skipped to save considerable time.
>
> This can speed up the secondary cpu boot and hotplug cpu online
> paths.
>
> Discussion thread:
> 	http://www.spinics.net/lists/arm-kernel/msg111124.html
>

There's already one way to do this with pre-calculated lpj.

Also, this isn't multi-platform friendly. You could accomplish the same 
thing using the clock api to get the core frequency of each core and 
only calculate lpj if the frequency is different.

Rob

  reply	other threads:[~2011-01-20 15:14 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-01-20  9:42 [PATCH] ARM: smp: Introduce ARCH_HAS_COMMON_CORES_CLOCK to speed-up boot Santosh Shilimkar
2011-01-20 15:14 ` Rob Herring [this message]
2011-01-20 15:36   ` Santosh Shilimkar
2011-01-20 16:34     ` Rob Herring
2011-01-21 13:43       ` Santosh Shilimkar
2011-01-21 14:23         ` Linus Walleij
2011-01-21 15:00         ` Rob Herring
2011-01-21 17:15           ` Russell King - ARM Linux
2011-01-22  7:44             ` [PATCH] ARM: smp: Introduce ARCH_HAS_COMMON_CORES_CLOCK tospeed-up boot Santosh Shilimkar
2011-01-22 21:20               ` Russell King - ARM Linux
2011-01-23  7:25                 ` [PATCH] ARM: smp: Introduce ARCH_HAS_COMMON_CORES_CLOCKtospeed-up boot Santosh Shilimkar
2011-01-21 17:08         ` [PATCH] ARM: smp: Introduce ARCH_HAS_COMMON_CORES_CLOCK to speed-up boot Russell King - ARM Linux
2011-01-20 16:21   ` Linus Walleij

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