From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753623Ab1A1HjQ (ORCPT ); Fri, 28 Jan 2011 02:39:16 -0500 Received: from one.firstfloor.org ([213.235.205.2]:33558 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751780Ab1A1HjO (ORCPT ); Fri, 28 Jan 2011 02:39:14 -0500 Date: Fri, 28 Jan 2011 08:39:09 +0100 From: Andi Kleen To: Andrew Morton Cc: Andi Kleen , Huang Ying , Linus Torvalds , Avi Kivity , "linux-kernel@vger.kernel.org" , "kvm@vger.kernel.org" , "Luck, Tony" , Dean Nelson , Marcelo Tosatti Subject: Re: [PATCH 1/2] mm, Make __get_user_pages return -EHWPOISON for HWPOISON page optionally Message-ID: <20110128073909.GC15569@one.firstfloor.org> References: <1294908168.4596.58.camel@yhuang-dev> <4D2ED737.6050802@redhat.com> <1294969036.4596.67.camel@yhuang-dev> <4D331054.4030206@redhat.com> <1295225259.10748.3.camel@yhuang-dev> <20110120155021.GA5996@amt.cnet> <1296113345.15213.87.camel@yhuang-dev> <20110127150705.f2cfe235.akpm@linux-foundation.org> <20110128005711.GB15569@one.firstfloor.org> <20110127171244.7a9442a7.akpm@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110127171244.7a9442a7.akpm@linux-foundation.org> User-Agent: Mutt/1.4.2.2i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > > Also longer term we'll get compilers that can do cross-file inlining > > for optimized builds. > > Which we'll probably need to turn off all over the place :( Why? > > > So please better avoid these kinds of micro optimizations unless > > it's a really really extremly speed critical path. > > It's not just speed and it's not just .text size, either. Calling a > ten-arg function consumes stack space. gcc is pretty good at handling tail calls. Take a look at the code it generates. -Andi -- ak@linux.intel.com -- Speaking for myself only.