From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=0.5 required=3.0 tests=DATE_IN_PAST_03_06, DKIM_INVALID,DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 40C8FC4321A for ; Fri, 28 Jun 2019 13:36:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0ED5D208E3 for ; Fri, 28 Jun 2019 13:36:42 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="ApTvu7OB" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726965AbfF1Ngl (ORCPT ); Fri, 28 Jun 2019 09:36:41 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:54550 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726906AbfF1Ngd (ORCPT ); Fri, 28 Jun 2019 09:36:33 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=Subject:Cc:To:From:Date:Message-Id: Sender:Reply-To:MIME-Version:Content-Type:Content-Transfer-Encoding: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=Hs9auHkF03NdeqtewD6fUm4GeHSf7zbsBEMAsta2Bvg=; b=ApTvu7OBW2b+RUTKP51nSjH3g bE8YUno0WpQa7s1eLfEBGNCGM7NAyUxTuQeqz2P2/wXgyX7+n3fSHvvDIjSzMw4oXaJT/xXeEd444 E1cS8j7b1l4aaRuT2UMkiIRs87MmGiyo262V9jOrqcZVZ/d2E4ca15p7TycRGVLpTwP54N4WFPBbd 3ddN9HbHXlJW6oOdD1HQ54w2bJpW28e4YUERvOfLHnOSnEItYpyXjZeDt2kOnrcLge+Zqz6eeKbBo W0PAs6mZbUwCryYLFeJ0ItkiXtwrZy1nj54vHrFpyBMgn7kgqeOGebZIUrHrsfGGQIGMbE+55VVmO xHUkkXd4Q==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by bombadil.infradead.org with esmtpsa (Exim 4.92 #3 (Red Hat Linux)) id 1hgr2r-0006t0-1A; Fri, 28 Jun 2019 13:36:05 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 0) id 7579820AB898D; Fri, 28 Jun 2019 15:36:03 +0200 (CEST) Message-Id: <20190628102113.360432762@infradead.org> User-Agent: quilt/0.65 Date: Fri, 28 Jun 2019 12:21:13 +0200 From: Peter Zijlstra To: x86@kernel.org, peterz@infradead.org, linux-kernel@vger.kernel.org Cc: Josh Poimboeuf , Steven Rostedt , Masami Hiramatsu , Daniel Bristot de Oliveira , Jason Baron , Nadav Amit , Andy Lutomirski , Eugeniy Paltsev , Vineet Gupta Subject: [RFC][PATCH 0/8] jump_label, x86: Support variable sized JMP instructions Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org After discussing jump_labels with Eugeny and Vineet the other day, I started playing with adding support for our 2 byte JMP/8 instruction. Much thanks to Josh for (re)discovering the .skip trick. These patches boot an x86_64 defconfig in kvm, so it must be perfect. Using the 2 byte jumps saves about ~6k text for an x86_64-defconfig build.