Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161405AbWJSNqJ (ORCPT ); Thu, 19 Oct 2006 09:46:09 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1161413AbWJSNqJ (ORCPT ); Thu, 19 Oct 2006 09:46:09 -0400 Received: from ns2.suse.de ([195.135.220.15]:42388 "EHLO mx2.suse.de") by vger.kernel.org with ESMTP id S1161405AbWJSNqH (ORCPT ); Thu, 19 Oct 2006 09:46:07 -0400 From: Andi Kleen To: Eric Dumazet Subject: Re: [PATCH] account_system_vtime() should be a macro, not a function Date: Thu, 19 Oct 2006 15:46:02 +0200 User-Agent: KMail/1.9.3 Cc: Andrew Morton , linux-kernel@vger.kernel.org References: <200610171747.34177.cijoml@volny.cz> <20061019014446.36410c81.akpm@osdl.org> <200610191543.18951.dada1@cosmosbay.com> In-Reply-To: <200610191543.18951.dada1@cosmosbay.com> MIME-Version: 1.0 Content-Disposition: inline Message-Id: <200610191546.02566.ak@suse.de> Content-Type: text/plain; charset="iso-8859-15" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 904 Lines: 21 On Thursday 19 October 2006 15:43, Eric Dumazet wrote: > [PATCH] account_system_vtime() should be a macro, not a function > > Because the way 'current' is implemented on some archs, it's better to use a > null macro for account_system_vtime(current) > > I discovered that gcc was (correctly) issuing one useless instruction (to > load %rax with current from pda) on x86_64 on irq_enter() and __irq_exit() > > This saves few bytes in kernel size, on archs where current is 'asm volatile' I dropped the asm volatile on x86-64 some time ago. Perhaps it should be dropped on the other architectures too. Then such hacks wouldn't be needed anywhere. -Andi - 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/