Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753094AbZAIROP (ORCPT ); Fri, 9 Jan 2009 12:14:15 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752592AbZAIRN4 (ORCPT ); Fri, 9 Jan 2009 12:13:56 -0500 Received: from bombadil.infradead.org ([18.85.46.34]:35362 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752570AbZAIRNz (ORCPT ); Fri, 9 Jan 2009 12:13:55 -0500 Date: Fri, 9 Jan 2009 12:13:25 -0500 From: Christoph Hellwig To: jim owens Cc: Ingo Molnar , Linus Torvalds , "H. Peter Anvin" , Chris Mason , Peter Zijlstra , Steven Rostedt , paulmck@linux.vnet.ibm.com, Gregory Haskins , Matthew Wilcox , Andi Kleen , Andrew Morton , Linux Kernel Mailing List , linux-fsdevel , linux-btrfs , Thomas Gleixner , Nick Piggin , Peter Morreale , Sven Dietrich Subject: Re: [patch] measurements, numbers about CONFIG_OPTIMIZE_INLINING=y impact Message-ID: <20090109171324.GA29587@infradead.org> References: <20090108141808.GC11629@elte.hu> <1231426014.11687.456.camel@twins> <1231434515.14304.27.camel@think.oraclecorp.com> <20090108183306.GA22916@elte.hu> <496648C7.5050700@zytor.com> <20090109130057.GA31845@elte.hu> <49675920.4050205@hp.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <49675920.4050205@hp.com> User-Agent: Mutt/1.5.18 (2008-05-17) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 855 Lines: 17 On Fri, Jan 09, 2009 at 09:03:12AM -0500, jim owens wrote: > They also know inlining may increase program object size. > That inlining will reduce object size on many architectures > if the function is small is just a happy side effect to them. The problem is that the threshold for that is architecture specific. While e.g. x86 has relatively low overhead of prologue/epilogue other architectures like s390 have enormous overhead. So handling this in the compiler would be optimal, but it would need at least whole-program optimization and a compiler aware of the inline assembly to get it half-way right. -- 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/