Re: clang --target=bpf missing on f23 was: Re: [PATCH 1/2] perf test: Add libbpf relocation checker

From	Alexei Starovoitov <alexei.starovoitov@gmail.com>
Newsgroups	linux.kernel
Subject	Re: clang --target=bpf missing on f23 was: Re: [PATCH 1/2] perf test: Add libbpf relocation checker
Date	2016-01-22 18:50 +0100
Message-ID	<qTO0q-7kv-5@gated-at.bofh.it> (permalink)
References	(1 earlier) <qTGcy-25g-27@gated-at.bofh.it> <qTM8i-5YV-15@gated-at.bofh.it> <qTNnI-73X-7@gated-at.bofh.it> <qTNH4-7bM-17@gated-at.bofh.it> <qTNQJ-7gK-1@gated-at.bofh.it>
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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.

Thread

[PATCH 0/2] perf bpf: Fix relocation error Wang Nan <wangnan0@huawei.com> - 2016-01-22 10:30 +0100
  [PATCH 1/2] perf test: Add libbpf relocation checker Wang Nan <wangnan0@huawei.com> - 2016-01-22 10:30 +0100
    Re: [PATCH 1/2] perf test: Add libbpf relocation checker Arnaldo Carvalho de Melo <acme@kernel.org> - 2016-01-22 16:50 +0100
      Re: [PATCH 1/2] perf test: Add libbpf relocation checker Alexei Starovoitov <alexei.starovoitov@gmail.com> - 2016-01-22 18:10 +0100
        clang --target=bpf missing on f23 was:  Re: [PATCH 1/2] perf test:  Add libbpf relocation checker Arnaldo Carvalho de Melo <acme@kernel.org> - 2016-01-22 18:30 +0100
          Re: clang --target=bpf missing on f23 was:  Re: [PATCH 1/2] perf  test: Add libbpf relocation checker Adam Jackson <ajax@redhat.com> - 2016-01-22 18:40 +0100
            Re: clang --target=bpf missing on f23 was:  Re: [PATCH 1/2] perf  test: Add libbpf relocation checker Alexei Starovoitov <alexei.starovoitov@gmail.com> - 2016-01-22 18:50 +0100
              Re: clang --target=bpf missing on f23 was:  Re: [PATCH 1/2] perf  test: Add libbpf relocation checker David Airlie <airlied@redhat.com> - 2016-01-22 22:10 +0100
            Re: clang --target=bpf missing on f23 was:  Re: [PATCH 1/2] perf  test: Add libbpf relocation checker Daniel Borkmann <daniel@iogearbox.net> - 2016-01-22 19:00 +0100
              Re: clang --target=bpf missing on f23 was:  Re: [PATCH 1/2] perf  test: Add libbpf relocation checker Arnaldo Carvalho de Melo <acme@kernel.org> - 2016-01-22 20:10 +0100

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