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=-12.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 C68F3C433DB for ; Tue, 9 Mar 2021 11:21:13 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 81D3F64F71 for ; Tue, 9 Mar 2021 11:21:13 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 81D3F64F71 Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from list by lists.xenproject.org with outflank-mailman.95360.180018 (Exim 4.92) (envelope-from ) id 1lJaQ9-0007di-O0; Tue, 09 Mar 2021 11:21:01 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 95360.180018; Tue, 09 Mar 2021 11:21:01 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lJaQ9-0007db-JV; Tue, 09 Mar 2021 11:21:01 +0000 Received: by outflank-mailman (input) for mailman id 95360; Tue, 09 Mar 2021 11:21:00 +0000 Received: from all-amaz-eas1.inumbo.com ([34.197.232.57] helo=us1-amaz-eas2.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lJaQ8-0007dW-T4 for xen-devel@lists.xenproject.org; Tue, 09 Mar 2021 11:21:00 +0000 Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id 2ab3b32d-04d1-47e6-a010-22ad3c2fed05; Tue, 09 Mar 2021 11:21:00 +0000 (UTC) Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 633B7AB8C; Tue, 9 Mar 2021 11:20:59 +0000 (UTC) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 2ab3b32d-04d1-47e6-a010-22ad3c2fed05 X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1615288859; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=J3u/aOz1TPlsD64Ph0ZqwRZWEf0MoIW76MeK41o1c2c=; b=aE2LzoBsQAlYeXlxa3BNT0koaENq+5DErU+D1DDBuQGdaIBp2Q5Go4kAqxG1BYglt7SP3Z QBskbM1k5mW5K7kpRxuIMVF+MW7Rzyy85WqnT2uHvz2mGB4hVxGC7pbxc+eQf+gc8y7stn 1kB+yRT/y5oiiqiTnchHjXz0vZ3jt+s= Subject: Re: [PATCH for-4.15] xen: Bump the minimum version of GCC supported to 4.9 (5.1 on arm64) To: Julien Grall Cc: Julien Grall , Andrew Cooper , George Dunlap , Ian Jackson , Stefano Stabellini , Wei Liu , xen-devel@lists.xenproject.org References: <20210306214148.27021-1-julien@xen.org> <1897022d-7591-3450-4e57-884a2860b13d@suse.com> <7fd07dc9-9c03-bb13-3907-c3c268a4e970@xen.org> <2de5160f-8636-5cdf-a20c-acaa2640c893@suse.com> From: Jan Beulich Message-ID: Date: Tue, 9 Mar 2021 12:20:58 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit On 08.03.2021 21:22, Julien Grall wrote: > On 08/03/2021 11:20, Jan Beulich wrote: >> On 08.03.2021 11:51, Julien Grall wrote: >>> On 08/03/2021 08:09, Jan Beulich wrote: >>>> Additionally - partly related to your own reply regarding the CI >>>> failures - imo there needs to be an analysis of what older distros >>>> will no longer build (at all or by default). >>> >>> Per the CI, this would be Ubuntu Trusty (and older), Centos 7 (and older) >>> >>> Do you have any other in mind? >> >> Our SLE12 (latest service pack is SP5 and still has a while to go >> to at least reach LTSS state) comes with gcc 4.8 as the default >> compiler. > > Thanks! That's good to know. Is it the old GCC Suse supports? Not sure I understand the question: The default compiler of this or any distro is of course (expected to be) supported by the vendor for the lifetime of the OS. >>>>> --- a/xen/include/xen/compiler.h >>>>> +++ b/xen/include/xen/compiler.h >>>>> @@ -5,6 +5,19 @@ >>>>> #error Sorry, your compiler is too old/not recognized. >>>>> #endif >>>>> >>>>> +#if CONFIG_CC_IS_GCC >>>>> +# if CONFIG_GCC_VERSION < 40900 >>>>> +/* https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58145 */ >>>> >>>> As per the bug report, the issue was determined to not be present >>>> in e.g. 4.3. Hence while such a bug may influence our choice of >>>> minimum version, I don't think it can reasonably be named here as >>>> the apparent only reason for the choice. Personally I don't think >>>> any justification should be put here. >>> >>> Ok. >>> >>>> >>>>> +# error Sorry, your version of GCC is too old - please use 4.9 or newer. >>>>> +# elif defined(CONFIG_ARM_64) && CONFIG_GCC_VERSION < 50100 >>>>> +/* >>>>> + * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63293 >>>>> + * https://lore.kernel.org/r/20210107111841.GN1551@shell.armlinux.org.uk >>>>> + */ >>>>> +# error Sorry, your version of GCC is too old - please use 5.1 or newer. >>>> >>>> From the bug entry the fix looks to have been backported to 4.9, >>>> or at least some (important?) branches thereof. >>> >>> It is not clear what's you are trying to point out. Mind clarifying? >> >> Some 4.9 compilers (perhaps widely used ones) may not have the bad >> issue, which puts under question their ruling out when the main >> reason for doing so is that bug. > > Well... We could surely try to hunt which GCC 4.9 has been fixed. But I > am not convinced this is useful, we would need to have an allowlist of > GCC compiler. Or probe the compiler for the bug in question. Jan