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=-11.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SIGNED_OFF_BY,SPF_PASS,USER_AGENT_NEOMUTT 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 CAE75C4360F for ; Thu, 4 Apr 2019 20:19:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9F2DB206B7 for ; Thu, 4 Apr 2019 20:19:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730754AbfDDUTD (ORCPT ); Thu, 4 Apr 2019 16:19:03 -0400 Received: from mx1.redhat.com ([209.132.183.28]:29839 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729184AbfDDUTD (ORCPT ); Thu, 4 Apr 2019 16:19:03 -0400 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id A26D130EBB5A; Thu, 4 Apr 2019 20:19:02 +0000 (UTC) Received: from treble (ovpn-125-158.rdu2.redhat.com [10.10.125.158]) by smtp.corp.redhat.com (Postfix) with ESMTPS id E03D119C4F; Thu, 4 Apr 2019 20:18:57 +0000 (UTC) Date: Thu, 4 Apr 2019 15:18:55 -0500 From: Josh Poimboeuf To: Miroslav Benes Cc: yamada.masahiro@socionext.com, michal.lkml@markovi.net, pmladek@suse.com, jikos@kernel.org, joe.lawrence@redhat.com, ggherdovich@suse.cz, linux-kbuild@vger.kernel.org, live-patching@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] kbuild: use -flive-patching when CONFIG_LIVEPATCH is enabled Message-ID: <20190404201855.xtvtgxaaomcmowrt@treble> References: <20190404184411.1392-1-mbenes@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20190404184411.1392-1-mbenes@suse.cz> User-Agent: NeoMutt/20180716 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.49]); Thu, 04 Apr 2019 20:19:02 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Apr 04, 2019 at 08:44:11PM +0200, Miroslav Benes wrote: > GCC 9 introduces a new option, -flive-patching. It disables certain > optimizations which could make a compilation unsafe for later live > patching of the running kernel. > > The option is used only if CONFIG_LIVEPATCH is enabled and $(CC) > supports it. > > Performance impact of the option was measured on three different > Intel machines - two bigger NUMA boxes and one smaller UMA box. Kernel > intensive (IO, scheduling, networking) benchmarks were selected, plus a > set of HPC workloads from NAS Parallel Benchmark. The tests were done on > upstream kernel 5.0-rc8 with openSUSE Leap 15.0 userspace. > > The majority of the tests is unaffected. The only significant exception > is the scheduler section which suffers 1-3% degradation. > > Evaluated-by: Giovanni Gherdovich > Signed-off-by: Miroslav Benes > --- > The patch is based on master branch of the livepatching tree on > git.kernel.org. > > Many thanks to Giovanni who ran the whole testing campaign and analyzed > the results. I archived the dashboard and detailed data. If anyone is > interested, we could probably set up a public website somewhere. Acked-by: Josh Poimboeuf While we're on the subject, I'm glad to see ongoing activity on klp-convert (though I haven't had a chance to follow the discussions). What's the status of the rest of the needed bits? - kgraft-analysis-tool - will this also be submitted for inclusion in the kernel tree? - Documentation about how to create a patch - The other bits I think Nicolai has been working on to eliminate all the manual steps -- Josh