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=DKIM_INVALID,DKIM_SIGNED, FSL_HELO_FAKE,MAILING_LIST_MULTI,SPF_PASS,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 A9390C64EB8 for ; Thu, 4 Oct 2018 09:01:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4ACBD2098A for ; Thu, 4 Oct 2018 09:01:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="TzK6NfA6" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4ACBD2098A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.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 S1727773AbeJDPxt (ORCPT ); Thu, 4 Oct 2018 11:53:49 -0400 Received: from mail-wr1-f67.google.com ([209.85.221.67]:40701 "EHLO mail-wr1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727190AbeJDPxs (ORCPT ); Thu, 4 Oct 2018 11:53:48 -0400 Received: by mail-wr1-f67.google.com with SMTP id d2-v6so4580814wro.7 for ; Thu, 04 Oct 2018 02:01:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:content-transfer-encoding:in-reply-to :user-agent; bh=I8r3A71406OutkwFn3d15NRczwxZZUohmDm3Zigkac8=; b=TzK6NfA6SMxP8HuGH0KODixI04bzmImqKQqU1w5vSZu7p9ug03wqanpxIY6IRt466H E6ELv1rp/+6xTTv3CJfeyD/iXDqiJOvXdHtYcD6/bwAsXfHgw1s+g5NinQbVKvTm748Q Td5i9F82qiDoKHNCwxLEANMQznJWP6Hf0OizXisGmkDArN4bMKMFob2R7/c5ly+TFjnc rfIuMVxEGSWIwSgFLUFA470B7yQCqdfemFUKj73JsBjwTAFcjq+G9CGZdEm5K+/W8LFs IN2j9V9gV291S3eIRKjPj37nNkdvontyYFVRZaTDciDghor2LRU1vVIre0ShmrKo65RB VCJQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition :content-transfer-encoding:in-reply-to:user-agent; bh=I8r3A71406OutkwFn3d15NRczwxZZUohmDm3Zigkac8=; b=op5L82IE5xpEawnZAXa/YZY07imOWaQnu3HGaoY5VmntdZsVPGADb9rS+gs8qDT/Be SYb+3PG17A5dkU5oOj9jNk3ZfmyGtmbSiR+oRM7zYyeou3u0bUutPNT8JXvqH5zmdt2B qt9ZytMk5jC5ZkSZr5Pa0YrQ62ZGMsEbL+m1BGbtrN2rdU9mcwZJOTMqcSjBYeY264lo qZTMdSjC0vms02rLYBSAaQMWW3QJTmzZPFkWSPGNfJJHSyxO9yT9ceP4bKKKc+jBY2mK V/+RcygKGLRnbI+zpwznABv623enVsXks/YcCD8TZIKa3XFkddNEl6vugxW6hEJ2gYZd maZQ== X-Gm-Message-State: ABuFfoiSntnOkwxAgJKrQ61/KqEF/4EveEBOHinQs77UehgtRJ6H9xGK C7GqPAdsUHmGeZ4AqWyaF6s= X-Google-Smtp-Source: ACcGV630//O9lQDqxtsZcgw7EuWCTLM0UFIFiF57nItsVdjMhsIHeT5ku0Is3ZcQOT+ESZgR533Olg== X-Received: by 2002:a05:6000:48:: with SMTP id k8mr3892521wrx.103.1538643691207; Thu, 04 Oct 2018 02:01:31 -0700 (PDT) Received: from gmail.com (2E8B0CD5.catv.pool.telekom.hu. [46.139.12.213]) by smtp.gmail.com with ESMTPSA id h82-v6sm4382757wmf.14.2018.10.04.02.01.30 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Thu, 04 Oct 2018 02:01:30 -0700 (PDT) Date: Thu, 4 Oct 2018 11:01:28 +0200 From: Ingo Molnar To: Nadav Amit Cc: Ingo Molnar , LKML , X86 ML , Thomas Gleixner , "H. Peter Anvin" , Jan Beulich , Josh Poimboeuf , Linus Torvalds , Peter Zijlstra , Andy Lutomirski Subject: Re: [PATCH v9 04/10] x86: refcount: prevent gcc distortions Message-ID: <20181004090128.GA21864@gmail.com> References: <20181003213100.189959-1-namit@vmware.com> <20181003213100.189959-5-namit@vmware.com> <20181004075755.GA3353@gmail.com> <65767CEA-370F-4180-9A81-116BE0BE2EA2@vmware.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <65767CEA-370F-4180-9A81-116BE0BE2EA2@vmware.com> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Nadav Amit wrote: > Finally, note that it’s not as if the binary always becomes smaller. > Overall, with the full patch-set it is slightly bigger. But still, that’s > how it was supposed to be if gcc wasn’t doing things badly. So what I cited was the changelog for the refcount patch, which according to your measurements reduced kernel image size. For other patches where size grew I left that text intact. And yes, in this particular case a slight increase in kernel size might actually be beneficial, as we get a lot more straight-line execution in exchange. So this is not a show-stopper property as long as the bloat isn't large. Thanks, Ingo