On 6/11/15 10:35 PM, Wang Nan wrote:
This is the 7th version which tries to introduce eBPF programs to perf. It enables 'perf record' to filter events using eBPF programs like:# perf record --event bpf-file.c sleep 1 and # perf record --event bpf-file.o sleep 1 This patch series is based on tip/perf/core (028c63b). Compare with v6 patch, this series totally refactor code for llvm compiling '.c' into BPF object file using LLVM. Including: 1. A specific file tools/perf/util/llvm-utils.c is introduced for holding all llvm/clang related work, instead of putting them into bpf-loader.c. 2. Automatically detect kernel include options by embedded shell script. 3. Use command line template to generate compiler commands instead of assemble cmdline with printf, passing variables using environment. Which enable users to define their own compiler commands. 4. Introduce '[llvm]' section to perf default config. 5 options can be configured, but all of them can be omitted: [llvm] # Path to clang. If omit, search it from $PATH. clang-path = "/path/to/clang" # Cmdline template. Following line shows its default value. # Environment variable is used to passing options. clang-bpf-cmd-template = "$CLANG_EXEC $CLANG_OPTIONS $KERNEL_INC_OPTIONS -Wno-unused-value -Wno-pointer-sign -working-directory $WORKING_DIR -c $CLANG_SOURCE -target bpf -O2 -o -" # Option passed to clang, will be passed to cmdline by $CLANG_OPTIONS. clang-opt = "-Wno-unused-value -Wno-pointer-sign" # kbuild directory. If not set, use /lib/modules/`uname -r`/build. # If set to "" deliberately, skip kernel header auto-detector. kbuild-dir = "/path/to/kernel/build" # Options passed to 'make' when detecting kernel header options. kbuild-opts = "ARCH=x86_64" Command line options '--clang-path' and '--clang-opt' is appended to 'perf record'. 5. LLVM and BPF opening testcase is adding into 'perf test': # perf test 37 37: Test LLVM searching and compiling : Ok 6. Warning and error messages improvement. 7. Issue clang command suit for newest clang which support '-target bpf', instead of calling 'clang -emit-llvm | llc -march=bpf' pipe.
All looks great to me. Piping clang into stdout to skip .o on a disk is a nice touch. 'usability hints' have improved as well. Thanks a lot for the hard work. btw, what compile times do you see? On my machine compiling basic hello_world.c with #include bpf_helpers.h and few kernel headers take: 0.02 sec So using .c is quite instant. Feels like interpreted language ;) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
