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=-3.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,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 D96ADC04E84 for ; Thu, 16 May 2019 02:21:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B480A20848 for ; Thu, 16 May 2019 02:21:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726454AbfEPCVp (ORCPT ); Wed, 15 May 2019 22:21:45 -0400 Received: from mga14.intel.com ([192.55.52.115]:2362 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725974AbfEPCVp (ORCPT ); Wed, 15 May 2019 22:21:45 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga103.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 15 May 2019 19:21:44 -0700 X-ExtLoop1: 1 Received: from hanghang-mobl1.ccr.corp.intel.com (HELO wfg-t570.sh.intel.com) ([10.254.212.137]) by FMSMGA003.fm.intel.com with ESMTP; 15 May 2019 19:21:37 -0700 Received: from wfg by wfg-t570.sh.intel.com with local (Exim 4.89) (envelope-from ) id 1hR61X-0006ww-Te; Thu, 16 May 2019 10:21:35 +0800 Date: Thu, 16 May 2019 10:21:35 +0800 From: Fengguang Wu To: Nathan Chancellor Cc: Arnd Bergmann , Leon Romanovsky , Jason Gunthorpe , "kbuild@01.org" , Ariel Levkovich , Eli Cohen , Mark Bloch , Doug Ledford , "linux-rdma@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Philip Li , Rong Chen Subject: Re: undefined reference to `__aeabi_uldivmod' after 25c13324d03d ("IB/mlx5: Add steering SW ICM device memory type") Message-ID: <20190516022135.6tnf3xx5mzctutxz@wfg-t540p.sh.intel.com> References: <20190514194510.GA15465@archlinux-i9> <20190515003202.GA14522@ziepe.ca> <20190515050331.GC5225@mtr-leonro.mtl.com> <20190515064043.GA944@archlinux-i9> <20190515064918.GA4807@archlinux-i9> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline In-Reply-To: <20190515064918.GA4807@archlinux-i9> User-Agent: NeoMutt/20170609 (1.8.3) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org CC current 0day kbuild test maintainers Philip and Rong. -fengguang On Tue, May 14, 2019 at 11:49:18PM -0700, Nathan Chancellor wrote: >On Wed, May 15, 2019 at 08:42:13AM +0200, Arnd Bergmann wrote: >> On Wed, May 15, 2019 at 8:40 AM Nathan Chancellor >> wrote: >> > On Wed, May 15, 2019 at 08:31:49AM +0200, Arnd Bergmann wrote: >> > > On Wed, May 15, 2019 at 7:04 AM Leon Romanovsky wrote: >> > > > On Tue, May 14, 2019 at 09:32:02PM -0300, Jason Gunthorpe wrote: >> > > > > On Tue, May 14, 2019 at 12:45:10PM -0700, Nathan Chancellor wrote: >> > > > > > Hi all, >> > > > > > >> > > > > > I checked the RDMA mailing list and trees and I haven't seen this >> > > > > > reported/fixed yet (forgive me if it has) but when building for arm32 >> > > > > > with multi_v7_defconfig and the following configs (distilled from >> > > > > > allyesconfig): >> > > > > > >> > > > > > CONFIG_INFINIBAND=y >> > > > > > CONFIG_INFINIBAND_ON_DEMAND_PAGING=y >> > > > > > CONFIG_INFINIBAND_USER_ACCESS=y >> > > > > > CONFIG_MLX5_CORE=y >> > > > > > CONFIG_MLX5_INFINIBAND=y >> > > > > > >> > > > > > The following link time errors occur: >> > > > > > >> > > > > > arm-linux-gnueabi-ld: drivers/infiniband/hw/mlx5/main.o: in function `mlx5_ib_alloc_dm': >> > > > > > main.c:(.text+0x60c): undefined reference to `__aeabi_uldivmod' >> > > > > > arm-linux-gnueabi-ld: drivers/infiniband/hw/mlx5/cmd.o: in function `mlx5_cmd_alloc_sw_icm': >> > > > > > cmd.c:(.text+0x6d4): undefined reference to `__aeabi_uldivmod' >> > > > > > arm-linux-gnueabi-ld: drivers/infiniband/hw/mlx5/cmd.o: in function `mlx5_cmd_dealloc_sw_icm': >> > > > > > cmd.c:(.text+0x9ec): undefined reference to `__aeabi_uldivmod' >> > > > > >> > > > > Fengguang, I'm surprised that 0-day didn't report this earlier.. >> > > > >> > > > I got many successful emails after I pushed this patch to 0-day testing. >> > > >> > > The long division warnings can compiler specific, and depend on certain >> > > optimization options, as compilers can optimize out certain divisions and >> > > replace them with multiplications and/or shifts, or prove that they can be >> > > replaced with a 32-bit division. If this is a case that gcc manages to >> > > optimize but clang does not, it might be worth looking into whether an >> > > optimization can be added to clang, in addition to improving the source. >> > >> > While I did run initially run into this with clang, the errors above are >> > with gcc (mainly to show this was going to be a universal problem and >> > not just something with clang). >> >> Which gcc version did you use here? Anything particularly old or particularly >> new? I think 0-day is on a fairly recent gcc-8, but not the latest gcc-9 >> release. > >8.2.0 it seems (I've been meaning to build from the 9.x branch though >since it appears that Arch's arm-linux-gnueabi-gcc isn't going to get >updated since it's in the AUR). >