From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Machek Subject: Re: Re: Re: DSDT in initrd Date: Wed, 28 May 2003 22:36:17 +0200 Sender: acpi-devel-admin-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Message-ID: <20030528203617.GA244@elf.ucw.cz> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: Errors-To: acpi-devel-admin-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Help: List-Post: List-Subscribe: , List-Unsubscribe: , List-Archive: To: "Grover, Andrew" Cc: acpi-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: linux-acpi@vger.kernel.org Hi! > > > > > What this enables is not only an elimination of the hassle > > > > of initrd, it > > > > > enables previously unmodularizable things like ACPI, or > > > > PCI, or all the > > > > > special code needed for x86 subarchs, or whatever other > > > > code that one > > > > > > > > subarchs are different issue. They can't > > > > be modularized without runtime overhead. > > > > > > How much runtime overhead? > > > > Hard to tell... It might be 10% in heavy-interrupt-load situation... > > Can you help me understand more about why this might be? Why would > modularized code be a performance hit over statically linked? There's a *lot* of small inline functions, look at mach_apic.h. You probably don't want them to be called using function pointer. Note note note: I'm not 100% convinced the pointer dereference is going to be noticable. I guess you have to talk to NUMAQ people to get the answers... > I was > assuming there would be another pointer dereference perhaps but that > certainly is not going to be noticed. We already have drivers in > modules, I'm trying to understand how for example a hi-perf nic driver > performs the same when modularized but subarch stuff wouldn't, when I'm > assuming it would just be like a "driver" for the particular > peculiarities of the platform. Because in each interrupt NIC has to be talked to once, but apic has to be talked to few times? Pavel -- When do you have a heart between your knees? [Johanka's followup: and *two* hearts?] ------------------------------------------------------- This SF.net email is sponsored by: eBay Get office equipment for less on eBay! http://adfarm.mediaplex.com/ad/ck/711-11697-6916-5