From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Zijlstra Subject: Re: [PATCH 1/3] acpi: add real mutex function calls Date: Mon, 21 Jul 2008 11:24:57 +0200 Message-ID: <1216632297.7257.31.camel@twins> References: <1216491411-24080-1-git-send-email-dwalker@mvista.com> <1216491411-24080-2-git-send-email-dwalker@mvista.com> <1216605078.4135.23.camel@yakui_zhao.sh.intel.com> <1216631698.7257.29.camel@twins> <48845425.9000607@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: Received: from bombadil.infradead.org ([18.85.46.34]:33064 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755171AbYGUJY6 (ORCPT ); Mon, 21 Jul 2008 05:24:58 -0400 In-Reply-To: <48845425.9000607@linux.intel.com> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Andi Kleen Cc: Zhao Yakui , Daniel Walker , linux-acpi@vger.kernel.org, Ingo Molnar , len.brown@intel.com On Mon, 2008-07-21 at 11:17 +0200, Andi Kleen wrote: > Peter Zijlstra wrote: > > On Mon, 2008-07-21 at 09:51 +0800, Zhao Yakui wrote: > >> On Sat, 2008-07-19 at 11:16 -0700, Daniel Walker wrote: > >>> Instead of re-using semaphores for the mutex operation, I've > >>> added usage of the kernel mutex for the os mutex implementation. > >>> > >> What is the advantage that the kernel mutex is used for the ACPI mutex > >> implementation instead of using semaphore? > >> And it seems that too much ACPICA source code is touched. > > > > You get help from lockdep, and also our goal is to fully eradicate > > semaphore usage. > > Issue is that ACPICA is shared with other OS source code and to replace > a major interface like this would mean replacing it for everyone. It > might end up with ACPICA just reimplementing a semaphore like wrapper if > semaphores really go away, but I don't really see that coming anyways. Andi, you know better than that.