From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S270040AbTGXTgS (ORCPT ); Thu, 24 Jul 2003 15:36:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S270047AbTGXTgS (ORCPT ); Thu, 24 Jul 2003 15:36:18 -0400 Received: from e35.co.us.ibm.com ([32.97.110.133]:63904 "EHLO e35.co.us.ibm.com") by vger.kernel.org with ESMTP id S270040AbTGXTgR (ORCPT ); Thu, 24 Jul 2003 15:36:17 -0400 Date: Thu, 24 Jul 2003 14:51:16 -0500 Subject: Re: [uClinux-dev] Kernel 2.6 size increase - get_current()? Content-Type: text/plain; charset=US-ASCII; format=flowed Mime-Version: 1.0 (Apple Message framework v552) Cc: David McCullough , uclinux-dev@uclinux.org, Linux Kernel Mailing List , "Ihar \"Philips\" Filipau" To: Alan Cox From: Hollis Blanchard In-Reply-To: <1059075436.7998.58.camel@dhcp22.swansea.linux.org.uk> Message-Id: <3038B2BC-BE10-11D7-B453-000A95A0560C@us.ibm.com> Content-Transfer-Encoding: 7bit X-Mailer: Apple Mail (2.552) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thursday, Jul 24, 2003, at 14:37 US/Central, Alan Cox wrote: > On Iau, 2003-07-24 at 16:30, Hollis Blanchard wrote: >> So you're arguing for more inlining, because icache speculative >> prefetch will pick up the inlined code? > > I'm arguing for short inlined fast paths and non inlined unusual > paths. > >> Or you're arguing for less, because code like get_current() which is >> called frequently could have a single copy living in icache? > > Depends how much the jump costs you. And also how big your icache is, and maybe even cpu/bus ratio, etc... which depend on the arch of course. So as I saw Ihar suggest earlier in this thread, perhaps there should be two inline directives: must_inline (for code whose correctness depends on it) and could_help_performance_inline. Then different archs could #define could_help_performance_inline as appropriate. -- Hollis Blanchard IBM Linux Technology Center