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

Alexei Starovoitov
2015-06-10T00:02:48Z

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

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.