From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754714AbcAVRmd (ORCPT ); Fri, 22 Jan 2016 12:42:33 -0500 Received: from mail-pf0-f173.google.com ([209.85.192.173]:33506 "EHLO mail-pf0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754330AbcAVRma (ORCPT ); Fri, 22 Jan 2016 12:42:30 -0500 Date: Fri, 22 Jan 2016 09:42:30 -0800 From: Alexei Starovoitov To: Adam Jackson Cc: Arnaldo Carvalho de Melo , Wang Nan , ast@kernel.org, linux-kernel@vger.kernel.org, Daniel Borkmann , Li Zefan , pi3orama@163.com, Dave Airlie Subject: Re: clang --target=bpf missing on f23 was: Re: [PATCH 1/2] perf test: Add libbpf relocation checker Message-ID: <20160122174230.GB10247@ast-mbp.thefacebook.com> References: <1453454841-232334-1-git-send-email-wangnan0@huawei.com> <1453454841-232334-2-git-send-email-wangnan0@huawei.com> <20160122154050.GH4034@kernel.org> <20160122170749.GA9608@ast-mbp.thefacebook.com> <20160122172222.GI4034@kernel.org> <1453484142.2587.7.camel@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1453484142.2587.7.camel@redhat.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jan 22, 2016 at 12:35:42PM -0500, Adam Jackson wrote: > On Fri, 2016-01-22 at 14:22 -0300, Arnaldo Carvalho de Melo wrote: > > > the 'bpf' target for clang is being used together with perf to > > build scriptlets into object code that then gets uploaded to the kernel > > via sys_bpf(), was the decision not to include 'bpf' just an accident? > > I wouldn't call it a "decision", that would imply intent. The main > reason I explicitly list targets for llvm is to limit the CPU backends > to arches Fedora actually runs on (which itself is because I really > only care about llvmpipe, and am only touching llvm because it's in my > way). Had no idea there was a bpf backend, so never thought to enable > it. > > llvm-3.7.0-4.fc2{3,4} are building now with the bpf backend enabled, > I'll create an update for F23 when it's built. thanks. if you want to reduce the size of binaries, you can probably disable nvptx/amdgcn/r600, since I doubt fedora ships with appropriate sdks that can take advantage of that.