Re: [RFC PATCH v6 32/32] perf record: Add LLVM options for compiling BPF scripts

Wangnan (F)
2015-06-10T00:18:06Z

On 2015/6/10 8:02, Alexei Starovoitov wrote:
> On 6/8/15 10:50 PM, Wang Nan wrote:
>> Although previous patch allows setting BPF compiler related options in
>> perfconfig, on some ad-hoc situation it still requires passing options
>> through cmdline. This patch introduces 4 options to 'perf record' for
>> this propose: --clang-path, --clang-opt, --llc-path and --llc-opt.
>
> looks good. I hope only --clang will be used from time to time.

Right. Please see another mail I posted. I'd like to generate command using
command template instead of printf() in next version.

> Today, indeed, --llc* are needed too.
>

With template, --llc can be removed now.

> btw, our experimental libbpfprog.so (which is clang and llvm libs
> compiled into single .so with C api for compiling .c into bpf):
> $ ls -lh libbpfprog.so
> -rw-r--r-- 1 ast ast 31M Jun 9 16:49 libbpfprog.so
>
> not tiny, but I think we should be able to include it into perf,
> then perf will only have build dependencies on llvm instead of
> run-time dependencies.
> We'll release this lib as soon as it's a bit more stable.
>

Could you please give me some URL to LLVM git repositories so I can
track your work on it?

Thank you.