From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Machek Subject: Re: Re: [PATCH] unneeded memory barrier Date: Fri, 12 Sep 2003 13:12:54 +0200 Sender: acpi-devel-admin-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Message-ID: <20030912111253.GL3944@openzaurus.ucw.cz> References: <3F60EA55.90008@terra.com.br> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <3F60EA55.90008-y7mWNqJcIDpfJ/NunPodnw@public.gmane.org> Errors-To: acpi-devel-admin-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Help: List-Post: List-Subscribe: , List-Unsubscribe: , List-Archive: To: Felipe W Damasio Cc: "Grover, Andrew" , mochel-3NddpPZAyC0@public.gmane.org, acpi-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: linux-acpi@vger.kernel.org Hi! > >> Patch against 2.6-test5 to remove an, IMHO, unneeded > >>memory barrier > >>on acpi/bus.c. Feel free to tell me I'm totally wrong, though :) > >> > >> If it looks good, please consider applying. > > > > > >- set_current_state(TASK_RUNNING); > >+ __set_current_state(TASK_RUNNING); > > > >My understanding of functions starting with __ was "use them but you > >better know what you're doing". This patch may be technically correct > >but does the unneeded barrier really hurt anything? If not then I > >think > >the regular version is ok. > > I don't think it hurts in terms of "enforcing ordering too > much", but that barrier isn't needed at all since it sets the state > to TASK_RUNNING... If setting to TASK_RUNNING never requires barier, I guess some __builtin_constant and ==TASK_RUNNING check in set_task_state is better idea. -- Pavel Written on sharp zaurus, because my Velo1 broke. If you have Velo you don't need... ------------------------------------------------------- This sf.net email is sponsored by:ThinkGeek Welcome to geek heaven. http://thinkgeek.com/sf