From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755240AbXLSLcY (ORCPT ); Wed, 19 Dec 2007 06:32:24 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752618AbXLSLcO (ORCPT ); Wed, 19 Dec 2007 06:32:14 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:55721 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752528AbXLSLcN (ORCPT ); Wed, 19 Dec 2007 06:32:13 -0500 Date: Wed, 19 Dec 2007 12:31:52 +0100 From: Ingo Molnar To: Herbert Xu Cc: Linux Kernel Mailing List , "David S. Miller" , netdev@vger.kernel.org Subject: Re: Inline local_bh_disable when TRACE_IRQFLAGS Message-ID: <20071219113152.GD20736@elte.hu> References: <20071219034033.GA5770@gondor.apana.org.au> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20071219034033.GA5770@gondor.apana.org.au> User-Agent: Mutt/1.5.17 (2007-11-01) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Herbert Xu wrote: > Hi Ingo: > > I noticed that local_bh_disable is now always out-of-line. The change > was made when TRACE_IRQFLAGS was added. However, with TRACE_IRQFLAGS > off, local_bh_disable does exactly the same work as before. In > particular, it does pretty much the same as what preempt_disable does > and the latter is always inline. > > So I'm wondering if it would be reasonable to make it out-of-line when > TRACE_IRQFLAGS is off. This may make a difference because the > networking stack is a frequent user of local_bh_disable and > local_bh_enable. do you mean to make it inline again? (btw., generally i think local_bh_disable() is a poor API because it is opaque about the data structure dependency that it governs. Explicit exclusion rules generally work better.) Ingo