Messages in this thread | | | Date | Wed, 8 Jul 2015 19:45:34 +0800 | From | "Wangnan (F)" <> | Subject | Re: [RFC PATCH v10 23/50] perf tools: Make perf depend on libbpf |
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On 2015/7/8 4:16, Arnaldo Carvalho de Melo wrote: > Em Tue, Jul 07, 2015 at 04:54:52PM -0300, Arnaldo Carvalho de Melo escreveu: >> Em Wed, Jul 01, 2015 at 02:14:11AM +0000, Wang Nan escreveu: >>> By adding libbpf into perf's Makefile, this patch enables perf to >>> build libbpf during building if libelf is found and neither NO_LIBELF >>> nor NO_LIBBPF is set. The newly introduced code is similar to libapi >>> and libtraceevent building in Makefile.perf. >>> MANIFEST is also updated for 'make perf-*-src-pkg'. >>> Append make_no_libbpf to tools/perf/tests/make. >>> 'bpf' feature check is appended into default FEATURE_TESTS and >>> FEATURE_DISPLAY, so perf will check API version of bpf in >>> /path/to/kernel/include/uapi/linux/bpf.h. Which should not fail >>> except when we are trying to port this code to an old kernel. >>> >>> Error messages are also updated to notify users about the disable of >>> BPF support of 'perf record' if libelf is missed or BPF API check >>> failed. >> Much better! > <SNIP> > >> Auto-detecting system features: > <SNIP> > >> ... bpf: [ on ] > <SNIP> > > But... I was all happy about this being linked with perf, went straight > ahead to try to use it! No, its not possible, I have to go thru a series > of other patches first... anticlimactic :-( > > So, please move this to just before we can use it, wiring it up should > mean, hey, try this "hello, world" eBPF program right now!
It is not an easy work, since there is a bulk of code in tools/perf/utils/bpf-loader.c depend on HAVE_LIBBPF_SUPPORT and CONFIG_LIBBPF. If put this patch the final one, we will make hundreds of lines of code avaiable by one patch. It is not good.
I have an idea that, put this patch after the llvm tester:
$ git log --oneline d011a28 perf tools: Make perf depend on libbpf 57ad12f perf tests: Add LLVM test for eBPF on-the-fly compiling 8c7e20b perf tools: Auto detecting kernel include options 442675f perf tools: Auto detecting kernel build directory dcd9304 perf tools: Call clang to compile C source to object code 864e2fb perf tools: Introduce llvm config options 8558c38 bpf tools: Link all bpf objects onto a list ...
Then before this patch, you can test llvm on-the-fly compiling without parsing the result .o:
$ perf test 38 38: Test LLVM searching and compiling : (skip bpf parsing) Ok
After this patch, libbpf should be compiled so basic libbpf parsing can be tested:
$ perf test 38 38: Test LLVM searching and compiling : Ok
> And please consider using the patches in the tmp.perf/ebpf branch in my > tree, the code contents are the same as yours, but I did some changes to > the comment texts, fixing some typos, etc. > > Also I fixed up the first two patches, the ones for the kernel, as it > was conflicting with some patches, including one where Steven Rostedt > renamed some trace_events structs and file names, that previously had > "ftrace" in it. > > Also next time please leave all this in a git branch I can try, to be > able to try the end result, doing that may help me while doing the next > review. > > I'll have to stop for today, will try as soon as you address the > comments to go back working on this. > > Thanks! > > - Arnaldo
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