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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, URIBL_BLOCKED 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 02456C43141 for ; Thu, 21 Jun 2018 08:16:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A1132208A1 for ; Thu, 21 Jun 2018 08:16:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="IAtrvfp0" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A1132208A1 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.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 S933114AbeFUIQg (ORCPT ); Thu, 21 Jun 2018 04:16:36 -0400 Received: from mail-it0-f68.google.com ([209.85.214.68]:38356 "EHLO mail-it0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932528AbeFUIPV (ORCPT ); Thu, 21 Jun 2018 04:15:21 -0400 Received: by mail-it0-f68.google.com with SMTP id v83-v6so3543393itc.3 for ; Thu, 21 Jun 2018 01:15:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=MPYff/pYZSFNhhQyfQx4STm/AKPvaIYbpQq5B+hPb1c=; b=IAtrvfp0nNlBYfmyZAz4N69nfQ4vgKg28zHTmBDxGSBWaSKnokcnbcRcU8YK8QcPI3 c1qBetIgHRYb20ojueQ+IFiRvaULum15CMwiiE55pCwwUrOcK6dL8m9CxbbJm0VqJbdz THbKHZ4atbQQCre4pdUTBSVFMJJ03Y2ApRT8g= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=MPYff/pYZSFNhhQyfQx4STm/AKPvaIYbpQq5B+hPb1c=; b=k/R/r8CrL+EryLDqMf3IHWLw5YGPDVc86pISHO3xXRtvKFA4USYjBAsjG1/ha4TXKE 5TZjRBPwJ37DuBEbEMryzR5OqfURJ7/gnq6qn6qXxthptH+jgZR0Z7pCcM9tG/lq6d8v /LpGA+MYBa7Cl6q8xOUKNubSpKVwXnfPTZqtn7bDnYuvcBbD0k/p1tw5oE9GYApYj43w NQAa5+qnUaA6+QrRdP2N0o78KmzZZddSyWMIGV2s3csmq2e6OSpWbHf4YcmCwBmF27tx pIfF0b1mYxJdXkRTPCT44kQKHwVjlLYeSSfr5cJOqwkuuofwFiSLq4waKnIuLpMDuL7B a4ug== X-Gm-Message-State: APt69E0nRoZ3fCU2j9orPvgQ7DBiByOzVi26yE5F8kZLGR/7Vkp+hSjH 9oshtCYVuh5n0xpYBkykHcqHdYWS8dmPm82pXpw= X-Google-Smtp-Source: ADUXVKIWCyDV2JOoKjWtBp3g10BpGGJEHFVyPrk0LZoOJO+ByDtsSskTIGyVBvsTXzE6drBfsVaVe7v+68RPB3VM12U= X-Received: by 2002:a24:8046:: with SMTP id g67-v6mr4251656itd.16.1529568921120; Thu, 21 Jun 2018 01:15:21 -0700 (PDT) MIME-Version: 1.0 References: <20180621080624.GO11011@yexl-desktop> In-Reply-To: <20180621080624.GO11011@yexl-desktop> From: Linus Torvalds Date: Thu, 21 Jun 2018 17:15:09 +0900 Message-ID: Subject: Re: [lkp-robot] [Kbuild] 050e9baa9d: netperf.Throughput_total_tps -5.6% regression (FYI) To: kernel test robot Cc: Masahiro Yamada , Linux Kernel Mailing List , LKP , Huang Ying , Aaron Lu Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jun 21, 2018 at 5:10 PM kernel test robot wrote: > > FYI, we noticed a -5.6% regression of netperf.Throughput_total_tps due to commit 050e9b ("Kbuild: rename CC_STACKPROTECTOR[_STRONG] config variables") That's perhaps a surprisingly large cost to stack protector, but you did move from "no stack protector at all": > $ grep STACKPROTECTOR config-4.17.0-11782-gbe779f0 > CONFIG_HAVE_CC_STACKPROTECTOR=y > CONFIG_CC_HAS_STACKPROTECTOR_NONE=y > # CONFIG_CC_STACKPROTECTOR is not set > CONFIG_CC_HAS_SANE_STACKPROTECTOR=y To having the *strong* stack protector enabled: > $ grep STACKPROTECTOR config-4.17.0-11783-g050e9baa > CONFIG_HAVE_CC_STACKPROTECTOR=y > CONFIG_CC_HAS_STACKPROTECTOR_NONE=y > CONFIG_STACKPROTECTOR=y > CONFIG_STACKPROTECTOR_STRONG=y > CONFIG_CC_HAS_SANE_STACKPROTECTOR=y so you're testing the "no overhead" case to the "worst overhead" case. Linus