From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753590AbYHZTwl (ORCPT ); Tue, 26 Aug 2008 15:52:41 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753305AbYHZTwb (ORCPT ); Tue, 26 Aug 2008 15:52:31 -0400 Received: from palinux.external.hp.com ([192.25.206.14]:52712 "EHLO mail.parisc-linux.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750769AbYHZTwa (ORCPT ); Tue, 26 Aug 2008 15:52:30 -0400 Date: Tue, 26 Aug 2008 13:50:51 -0600 From: Matthew Wilcox To: Daniel Walker Cc: Andi Kleen , linux-kernel@vger.kernel.org, Linus Torvalds , Ingo Molnar , Peter Zijlstra , Len Brown , Robert Moore , linux-acpi@vger.kernel.org Subject: Re: [PATCH 4/4] acpi: semaphore removal Message-ID: <20080826195051.GF23698@parisc-linux.org> References: <1219777186-4787-1-git-send-email-dwalker@mvista.com> <1219777186-4787-2-git-send-email-dwalker@mvista.com> <1219777186-4787-3-git-send-email-dwalker@mvista.com> <1219777186-4787-4-git-send-email-dwalker@mvista.com> <20080826191335.GE23698@parisc-linux.org> <1219779046.3797.12.camel@dhcp32.mvista.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1219779046.3797.12.camel@dhcp32.mvista.com> User-Agent: Mutt/1.5.13 (2006-08-11) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Aug 26, 2008 at 12:30:46PM -0700, Daniel Walker wrote: > On Tue, 2008-08-26 at 13:13 -0600, Matthew Wilcox wrote: > > On Tue, Aug 26, 2008 at 11:59:49AM -0700, Daniel Walker wrote: > > > The semaphore usage in ACPI is more like completions. The ASL > > > > Huh? They are semaphores. They're not 'more like completions' at all. > > You can clearly make a completion out of a semaphore, but we have a > completion API .. ACPI is using locked semaphores, and essentially > re-making completions with the semaphore API.. What makes you think that? executer/excreate.c: status = acpi_os_create_semaphore(ACPI_NO_UNIT_LIMIT, 0, executer/exsystem.c: acpi_os_create_semaphore(ACPI_NO_UNIT_LIMIT, 0, &temp_semaphore); namespace/nsaccess.c: acpi_os_create_semaphore(1, 0, osl.c:acpi_os_create_semaphore(u32 max_units, u32 initial_units, acpi_handle * handle) All users set 'initial_units' to 0. -- Matthew Wilcox Intel Open Source Technology Centre "Bill, look, we understand that you're interested in selling us this operating system, but compare it to ours. We can't possibly take such a retrograde step."