Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932640AbZJLPqL (ORCPT ); Mon, 12 Oct 2009 11:46:11 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932619AbZJLPqJ (ORCPT ); Mon, 12 Oct 2009 11:46:09 -0400 Received: from smtp2.ultrahosting.com ([74.213.174.253]:49342 "EHLO smtp.ultrahosting.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S932611AbZJLPqI (ORCPT ); Mon, 12 Oct 2009 11:46:08 -0400 Date: Mon, 12 Oct 2009 11:38:25 -0400 (EDT) From: Christoph Lameter X-X-Sender: cl@gentwo.org To: Mathieu Desnoyers cc: Peter Zijlstra , akpm@linux-foundation.org, linux-kernel@vger.kernel.org, Pekka Enberg , Tejun Heo , Mel Gorman , mingo@elte.hu Subject: Re: [this_cpu_xx V5 19/19] SLUB: Experimental new fastpath w/o interrupt disable In-Reply-To: <20091012153844.GA29116@Krystal> Message-ID: References: <20091008171750.GA3370@Krystal> <20091008191754.GA12729@Krystal> <20091008203724.GA15798@Krystal> <20091012135600.GB15605@Krystal> <20091012152627.GA27835@Krystal> <20091012153844.GA29116@Krystal> User-Agent: Alpine 1.10 (DEB 962 2008-03-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 689 Lines: 20 On Mon, 12 Oct 2009, Mathieu Desnoyers wrote: > local_irq_enable(); > preempt_enable(); <- barrier() > > In the first scenario, the compiler barrier is at the beginning of the > slow path function, which should impose less restrictions on the compiler > optimizations. Again: The next statement is a call to a function that calls the page allocator. Its one call vs two for me. Plus the flow of things is much cleaner and less obfuscated. -- 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/