Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Mon, 29 Jul 2002 03:58:21 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Mon, 29 Jul 2002 03:58:21 -0400 Received: from smtpzilla3.xs4all.nl ([194.109.127.139]:11027 "EHLO smtpzilla3.xs4all.nl") by vger.kernel.org with ESMTP id ; Mon, 29 Jul 2002 03:58:13 -0400 Date: Mon, 29 Jul 2002 10:01:26 +0200 (CEST) From: Roman Zippel X-X-Sender: roman@serv To: David Howells cc: Christoph Hellwig , "Adam J. Richter" , Subject: Re: Patch: linux-2.5.29 __downgrade_write() for CONFIG_RWSEM_GENERIC_SPINLOCK In-Reply-To: <9911.1027928536@warthog.cambridge.redhat.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 957 Lines: 24 Hi, On Mon, 29 Jul 2002, David Howells wrote: > > You don't really need that extra argument, testing sem->activity should do > > the same job. > > If you exchange the wakewrite (or sem->activity) test and the > > waiter->flags you can fold it into the next test (this means all the extra > > work would only be done, if we have a writer waiting at the top). > > The reason for doing it this way is that it allows the compiler to discard > parts of the function when inlining it since the value is set at compile time > rather than being worked out at runtime. The value itself should be > disappeared entirely by the compiler. Did you look at the code? gcc should be able to optimize that itself. bye, Roman - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/