From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Brownell Subject: Re: Performance of spi_mpc83xx.c sucks. Date: Tue, 2 Dec 2008 11:10:52 -0800 Message-ID: <200812021110.52964.david-b@pacbell.net> References: <1224605947.14078.17.camel@gentoo-jocke.transmode.se> <200812021017.11880.david-b@pacbell.net> <040601c954ab$554cff20$ffe6fd60$@Tjernlund@transmode.se> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org To: "Joakim Tjernlund" Return-path: In-Reply-To: <040601c954ab$554cff20$ffe6fd60$@Tjernlund-SNLAxHN9vbcOP4wsBPIw7w@public.gmane.org> Content-Disposition: inline List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: spi-devel-general-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: linux-spi.vger.kernel.org On Tuesday 02 December 2008, Joakim Tjernlund wrote: > Oh, so the kernel thread actually gets pre-empted(is that a word?) > once it has consumed its "time slice"? And potentially at other times. When an IRQ arrives and is handled, that's a form of non-task preemption. And when that IRQ enables a higher-priority task, the lower priority one can be preempted in a more usual manner. > Do I need to turn on > pre-empt support in the kernel for this? To get some kinds of preemption, yes. But it's not strictly required. - Dave ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/