Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753692Ab3HFUdY (ORCPT ); Tue, 6 Aug 2013 16:33:24 -0400 Received: from mail.openrapids.net ([64.15.138.104]:34508 "EHLO blackscsi.openrapids.net" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752042Ab3HFUdX (ORCPT ); Tue, 6 Aug 2013 16:33:23 -0400 Date: Tue, 6 Aug 2013 16:33:19 -0400 From: Mathieu Desnoyers To: Steven Rostedt Cc: Linus Torvalds , LKML , gcc , Ingo Molnar , "H. Peter Anvin" , Thomas Gleixner , David Daney , Behan Webster , Peter Zijlstra , Herbert Xu Subject: Re: [RFC] gcc feature request: Moving blocks into sections Message-ID: <20130806203319.GA16170@Krystal> References: <1375721715.22073.80.camel@gandalf.local.home> <1375725328.22073.101.camel@gandalf.local.home> <1375727977.22073.112.camel@gandalf.local.home> <1375798783.25420.30.camel@gandalf.local.home> <1375811885.25420.44.camel@gandalf.local.home> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1375811885.25420.44.camel@gandalf.local.home> X-Editor: vi X-Info: http://www.efficios.com User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1513 Lines: 42 * Steven Rostedt (rostedt@goodmis.org) wrote: > On Tue, 2013-08-06 at 10:48 -0700, Linus Torvalds wrote: > > > So I wonder if this is a "ok, let's not bother, it's not worth the > > pain" issue. 128 bytes of offset is very small, so there probably > > aren't all that many cases that would use it. > > OK, I'll forward port the original patches for the hell of it anyway, > and post it as an RFC. Let people play with it if they want, and if it > seems like it would benefit the kernel perhaps we can reconsider. > > It shouldn't be too hard to do the forward port, and if we don't ever > take it, it would be a fun exercise regardless ;-) > > Actually, the first three patches should be added as they are clean ups > and safety checks. Nothing to do with the actual 2-5 byte jumps. They > were lost due to their association with the complex patches. :-/ Steve, perhaps you could add a mode to your binary rewriting program that counts the number of 2-byte vs 5-byte jumps found, and if possible get a breakdown of those per subsystem ? It might help us getting a clearer picture of how many important sites, insn cache-wise, are being shrinked by this approach. Thanks, Mathieu > > -- Steve > > -- Mathieu Desnoyers EfficiOS Inc. http://www.efficios.com -- 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/