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=-2.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED, 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 43E2FC32789 for ; Sun, 4 Nov 2018 23:39:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DA0652082A for ; Sun, 4 Nov 2018 23:39:19 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="lbzEBTLZ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DA0652082A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com 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 S1729554AbeKEIzo (ORCPT ); Mon, 5 Nov 2018 03:55:44 -0500 Received: from mail-pl1-f195.google.com ([209.85.214.195]:37786 "EHLO mail-pl1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726957AbeKEIzo (ORCPT ); Mon, 5 Nov 2018 03:55:44 -0500 Received: by mail-pl1-f195.google.com with SMTP id p6-v6so3501996pll.4; Sun, 04 Nov 2018 15:39:01 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=2b76jeE14kiA/hiCWYGI9qRvEkd0f0ntH5BI3esnAxA=; b=lbzEBTLZXs12SkrtobuSNWg/s4ezveoEaNAss0VT8u+owjVnxFf126QB7PP7yWF21+ hlcV6jFj9siBreYldN5bz6o1zLoQyx6IQ7V5GEC6TKmp2h2SfHU6z9IzYNk/ZSw8wwRr 8Zuv7dfUCgx4VKWa6SzZuSMQGvgA3D1AhL80ucYhEglL+J9EkatGSyY7dyAAzGIfgxp7 P09LUV1FZHOwZVxwx5MrtedxpegYgp1tiQakZJG0v9q72UBWGUAeO/f6ddQZPBY4JJ82 zH5HROy4rTPTbjGV/0xwCr5kAqCIWA5n34p1MHxI6ErbQO4jAvDpf077apYzGh57eiBD wZaQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=2b76jeE14kiA/hiCWYGI9qRvEkd0f0ntH5BI3esnAxA=; b=MG23ixvMZ1zjj8lehUbxo25f9QGyTsgMnEptv6SQkeyKJ8lIt1NsSiJFEGVUgTabZO pdFLbyaPOUOyAE3cuEwQBkJHh34W4CdpEF55rExGTQVB0dxzeoqtVnv4XXmUWMqbt2DE G8O8KHiMf3oxBm0F32FaU/7SAHjrRu4Wn26dfcGxSTBW27zGKDEX4FQdu2KR73kemN58 yCHZ017b0FQOqMavJohxIrzoJyGmxVcedYAprocyCPMz9Bi6FWFhvd87D6jUR3fomfO/ Ju9RHYqeqwHAwwMQXwpVXDBomfabcaZCaulo8KYaieGKBq+diEDa4CyU59PNptBiRaDU VnBw== X-Gm-Message-State: AGRZ1gJau2TQAQzWNqd6Z5ESOJZXmByv/MrbXfAF8t3yN63GYy8SxDnv 3LAjya+51FMWAXYoieDDid0= X-Google-Smtp-Source: AJdET5ef6gNlfoC1fBqdmW7PaAv5M9zb2oBJhNCO1ibGrS/XFn7NnTLuxQK0Cr3YcX3mlsej4Ml17g== X-Received: by 2002:a17:902:4083:: with SMTP id c3-v6mr20079620pld.181.1541374741048; Sun, 04 Nov 2018 15:39:01 -0800 (PST) Received: from mail.google.com ([2001:19f0:6001:4ff6:5400:1ff:feb7:a195]) by smtp.gmail.com with ESMTPSA id n26-v6sm28466051pfh.166.2018.11.04.15.38.59 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Sun, 04 Nov 2018 15:39:00 -0800 (PST) Date: Sun, 4 Nov 2018 23:38:58 +0000 From: Changbin Du To: Masahiro Yamada Cc: Arnd Bergmann , Changbin Du , Randy Dunlap , Stephen Rothwell , Linux-Next Mailing List , Linux Kernel Mailing List , Steven Rostedt , Hans de Goede , Greg Kroah-Hartman Subject: Re: linux-next: Tree for Oct 31 (vboxguest) Message-ID: <20181104233857.b4ou3b7doclw2vi2@mail.google.com> References: <20181031145907.1ee2e866@canb.auug.org.au> <661e44c7-396a-6d58-efa7-ed292f2677c6@infradead.org> <20181101142946.u5luuctqav6fec6k@mail.google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20180716-508-7c9a6d Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Nov 04, 2018 at 11:43:44AM +0900, Masahiro Yamada wrote: > On Sat, Nov 3, 2018 at 12:55 AM Arnd Bergmann wrote: > > > > On 11/2/18, Masahiro Yamada wrote: > > > On Thu, Nov 1, 2018 at 11:32 PM Changbin Du wrote: > > >> On Thu, Nov 01, 2018 at 12:32:48PM +0900, Masahiro Yamada wrote: > > > > > > How about clang? > > > > > > For clang, -Og might be equivalent to -O1 at this moment, but I am not > > > sure. > > > > > > In my understanding, Clang does not inline functions marked with 'static > > > inline' > > > for -Og (or -O1) optimization level. > > > > > > Theoretically, 'inline' keyword is a just hint for the compiler, after all. > > > > I think this means that we cannot build the kernel in that configuration, > > at least with CONFIG_OPTIMIZE_INLINING=y. Without that option, > > every 'inline' becomes 'always_inline'. > > > > Sorry, I missed that fact. > > > At this moment of time, it is OK given the following: > > - CONFIG_OPTIMIZE_INLINING is defined only for x86 > - Clang cannot build x86 due to missing asm-goto > > > However, Clang with -Og > does not inline even such simple code like this: > > > -----test code------ > static inline int foo(int x) > { > return x; > } > > int bar(int x) > { > return foo(x); > } > ------------------- > > > > $ clang -Og -c -o bar.o bar.c > $ objdump -d bar.o > bar.o: file format elf64-x86-64 > > > Disassembly of section .text: > > 0000000000000000 : > 0: eb 0e jmp 10 > 2: 66 2e 0f 1f 84 00 00 nopw %cs:0x0(%rax,%rax,1) > 9: 00 00 00 > c: 0f 1f 40 00 nopl 0x0(%rax) > > 0000000000000010 : > 10: 89 f8 mov %edi,%eax > 12: c3 retq > > I see. Thanks for your explanation. So I think we should disable CONFIG_DEBUG_EXPERIENCE for clang. Do you know how to distinguish different copmilers in Kconfig? > > -- > Best Regards > Masahiro Yamada -- Thanks, Changbin Du