From owner-freebsd-hackers@freebsd.org Fri Aug 3 21:13:10 2018 Return-Path: Delivered-To: freebsd-hackers@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id CDE9D105100D for ; Fri, 3 Aug 2018 21:13:09 +0000 (UTC) (envelope-from marklmi@yahoo.com) Received: from sonic317-21.consmr.mail.gq1.yahoo.com (sonic317-21.consmr.mail.gq1.yahoo.com [98.137.66.147]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id EEE947587E for ; Fri, 3 Aug 2018 21:13:08 +0000 (UTC) (envelope-from marklmi@yahoo.com) X-YMail-OSG: 4WSHpvUVM1l7OpOTmJW3nxJmARMzGOhHWSWrA.d7Ww98uI.TKeEMGwToYb_Tvjj MBs1NkbV9r4zoWnt1rWlKm0FhLMt1Kqzvywq7tvrSb_QnX7AoxsKN4IMubB8Uz4W0ZtW.CdD8XkL jhIu4c7RP1VlM8JeQxwGdXEXJfJFBZN.y3DTliALakz724iZt6IabC_5MA8Y_jkNKWD6sqenI0wW uN1utFoLaoAW.diaGhX4tukuZNzutq0AxCabGYHplztxWCJJmWRWAGKpEHa2EsuxT873Gc7BJQrA bhDs0dKbdjUPCTAQ_RUPKFhkgTynqGMOOeODH7Mr11dRKKAriUR7FmT8e0r.4DaFMs_O8ZO8Fo.m RkR9d2RxhhSZw4cKmXrxUrduZEG9fG4GcYeErylxMgyyZhgP10NLYJEzjSmLtupZT1wwrn.EB61v limR_ZkETv4Dm6jJwlJ_McNvNP_SNxF.xEGn5OY30bednnj22Qyp5zQlsKFGQo25NiYCOiscweLl d7JriiHNOu2s3UcGbPuirzVeZTddCaaDdvQv7FVSdseGXOva3tzhdCzjfhLUbT9_rLDwIfpKVY1B acvachwn8N0VW3Z6XUZYO5Uypbn7W02oONgepVU3Cv8Quy9_sGSu2fmC9oP5OaPwxbjARHOnLmnm qokRjfyOjmsOgpWchPZRcJ3dfk0pF2WG05clwb0Oc2z9CchBr78KiezHgLdAENeFXl8FtXRxFXKT .Ydrslm0TlFSPKcwzHbOPG.QfRGCG.lhTApaMnXCxuVqWtkTuaWlLdC.fKcaXgvUh0URE9rPfZWk xAa0fSNB9J21eWRemM15MaMxsTVJTLGDm8kSYCN.XAvJSmiZsqUNEXwqtbmsM7OiVzjnNA8fvRqf uqm_dik4AwDUucZk5PULvGcQX_uz9ucXY0xQYcDqzdri8MsvH1co1IIZeu1WV7Ne3q1abdec0JME sOPSZwa1rxVzqtW2gwriSCDfwl0HLL7If1WJjPpzwZ0gx6kaJDCYKnhno4LIHVqmPhyvuN4lXPqJ gdf2plRAEgbwGEfo79g-- Received: from sonic.gate.mail.ne1.yahoo.com by sonic317.consmr.mail.gq1.yahoo.com with HTTP; Fri, 3 Aug 2018 21:13:01 +0000 Received: from ip70-189-131-151.lv.lv.cox.net (EHLO [192.168.0.105]) ([70.189.131.151]) by smtp412.mail.gq1.yahoo.com (Oath Hermes SMTP Server) with ESMTPA ID 37df12fa32bf2493899491448ee57466; Fri, 03 Aug 2018 21:12:56 +0000 (UTC) Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 11.5 \(3445.9.1\)) Subject: Re: svn commit: r335873 - in head: . sys/amd64/amd64 sys/amd64/include sys/conf sys/i386/i386 sys/i386/include sys/sys sys/vm From: Mark Millard In-Reply-To: <20180801075704.GS40119@kib.kiev.ua> Date: Fri, 3 Aug 2018 14:12:55 -0700 Cc: mmacy@FreeBSD.org, svn-src-head@freebsd.org, freebsd-hackers@freebsd.org, freebsd-amd64@freebsd.org Content-Transfer-Encoding: quoted-printable Message-Id: <3910BFAA-45CF-4A5F-AF08-A47585BFF9C2@yahoo.com> References: <226713AF-FC51-4A44-93E1-8264B1BD2C8A@yahoo.com> <20180801075704.GS40119@kib.kiev.ua> To: Konstantin Belousov X-Mailer: Apple Mail (2.3445.9.1) X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.27 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 03 Aug 2018 21:13:10 -0000 On 2018-Aug-1, at 12:57 AM, Konstantin Belousov = wrote: >=20 > On Tue, Jul 31, 2018 at 06:46:31PM -0700, Mark Millard via = freebsd-amd64 wrote: >>> Author: mmacy >>> Date: Mon Jul 2 19:48:38 2018 >>> New Revision: 335873 >>> URL:=20 >>> https://svnweb.freebsd.org/changeset/base/335873 >>>=20 >>>=20 >>> Log: >>> inline atomics and allow tied modules to inline locks >>>=20 >>> - inline atomics in modules on i386 and amd64 (they were always >>> inline on other arches) >>> - allow modules to opt in to inlining locks by specifying >>> MODULE_TIED=3D1 in the makefile >>=20 >> I recently found the following about ABI incompatibilities >> between clang and gcc relative to C11 language based >> atomics: >>=20 >> https://bugs.llvm.org/show_bug.cgi?id=3D26462 >>=20 >> 26462 ??? GCC/clang C11 _Atomic incompatibility >>=20 >>=20 >> So are there implications about building the kernel >> vs. modules that overall mix the toolchains once >> modules are loaded? Do the toolchains need to match, >> at least for amd64 and i386 TARGET_ARCH 's? > This is irrelevant since kernel does not use C11 atomics, we roll > our own version, which tries to follow C11 model. >=20 > Lack of the ABI for atomics is one of the reason to not use compiler > C11 atomics in kernel and C runtime. Thanks for the information: good to know. There are other things around that use C11 atomics, such as in: src/contrib/ofed/librdmacm/ (This is part of why https://reviews.freebsd.org/D16585 is out for updating stdatomic.h (and sys/cdefs.h ): so that fairly modern gcc vintages can build world with such involved.) =3D=3D=3D Mark Millard marklmi at yahoo.com ( dsl-only.net went away in early 2018-Mar)