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=-2.1 required=3.0 tests=DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,T_DKIM_INVALID, USER_AGENT_MUTT autolearn=ham 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 A0E3AC43142 for ; Thu, 28 Jun 2018 09:28:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4FBD727163 for ; Thu, 28 Jun 2018 09:28:32 +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="qJeCeDP5" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4FBD727163 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935101AbeF1J2a (ORCPT ); Thu, 28 Jun 2018 05:28:30 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:60668 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933194AbeF1J23 (ORCPT ); Thu, 28 Jun 2018 05:28:29 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=hYYDbc+R/nlM7I17YKyvqtFKsVgFSEudSqAqJlnY2uU=; b=qJeCeDP5a+y7p4GEUxiAXIW1Y z6Dda/XYV+Hp4qp5rEGshI9MPzZ2eFigfx0OBM22dFIYBH3o6GKzF/075nHPYNG3eIrLuVVJCCnJ9 zs0vsNlSIf0j42etYL2dZM4OsreKJ3I4MjS1jb9tv0EvBRpyGMogSR+q4WUqm2oGCfjGmxghLWq2T f0Up4y/eaLHnkNqGDF7h6rQQkBPkOGCDsVcbqvUG9d+C6Gxx6+bDCRtkREE86G6mcZlVThdPPr6gh NayuQ+12xvy2f//xP26QG+cEmiKjOT79+GnUsh7cWd8N0Us4744UzYPNw4wojOM9Bj7RPYHgTWv1l UNSg9RONA==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by bombadil.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1fYTDt-0007Jw-FY; Thu, 28 Jun 2018 09:28:17 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id DBEE52029764D; Thu, 28 Jun 2018 11:28:15 +0200 (CEST) Date: Thu, 28 Jun 2018 11:28:15 +0200 From: Peter Zijlstra To: Ard Biesheuvel Cc: Linux Kernel Mailing List , linux-arm-kernel , the arch/x86 maintainers , Catalin Marinas , Will Deacon , Thomas Gleixner , Ingo Molnar , Arnd Bergmann , Steven Rostedt , namit@vmware.com Subject: Re: [PATCH 5/5] x86/kernel: jump_table: use relative references Message-ID: <20180628092815.GD2494@hirez.programming.kicks-ass.net> References: <20180627160604.8154-1-ard.biesheuvel@linaro.org> <20180627160604.8154-6-ard.biesheuvel@linaro.org> <20180628083107.GY2494@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.0 (2018-05-17) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jun 28, 2018 at 10:34:54AM +0200, Ard Biesheuvel wrote: > On 28 June 2018 at 10:31, Peter Zijlstra wrote: > > On Wed, Jun 27, 2018 at 06:06:04PM +0200, Ard Biesheuvel wrote: > >> Similar to the arm64 case, 64-bit x86 can benefit from using 32-bit > >> relative references rather than 64-bit absolute ones when emitting > >> struct jump_entry instances. Not only does this reduce the memory > >> footprint of the entries themselves by 50%, it also removes the need > >> for carrying relocation metadata on relocatable builds (i.e., for KASLR) > >> which saves a fair chunk of .init space as well (although the savings > >> are not as dramatic as on arm64) > > > > This will conflict with: > > > > https://lkml.kernel.org/r/20180622172212.199633-10-namit@vmware.com > > Thanks for the head's up. Fortunately, it does not conflict > fundamentally, so it should be a straight-forward rebase after that > code is merged. Yeah, shouldn't be hard to cure. There's another patch set that might have a little conflict, but that's not near ready I think, so that'll have to just cope with things shifting underneath (and there too, the fixup shouldn't be hard). > Do you think this is likely to get merged for v4.19? I'm thinking it is near ready so it might, but I'm not in charge of those bits :-)