Hi Arnaldo, On Thu, Jun 06, 2019 at 03:29:41PM -0300, Arnaldo Carvalho de Melo wrote: > Em Thu, Jun 06, 2019 at 10:35:32PM +0800, Leo Yan escreveu: > > On Thu, Jun 06, 2019 at 11:08:00AM -0300, Arnaldo Carvalho de Melo wrote: > > > Em Thu, Jun 06, 2019 at 05:48:45PM +0800, Leo Yan escreveu: > > > > To build this program successfully with clang, there have three > > > > compiler options need to be specified: > > > > > > > > - Header file path: tools/perf/include/bpf; > > > > - Specify architecture; > > > > - Define macro __NR_CPUS__. > > > > > > So, this shouldn't be needed, all of this is supposed to be done > > > automagically, have you done a 'make -C tools/perf install'? > > > > I missed the up operation. But after git pulled the lastest code base > > from perf/core branch and used the command 'make -C tools/perf > > install', I still saw the eBPF build failure. > > > > Just now this issue is fixed after I removed the config > > 'clang-bpf-cmd-template' from ~/.perfconfig; the reason is I followed > > up the Documentation/perf-config.txt to set the config as below: > > > > clang-bpf-cmd-template = "$CLANG_EXEC -D__KERNEL__ $CLANG_OPTIONS \ > > $KERNEL_INC_OPTIONS -Wno-unused-value \ > > -Wno-pointer-sign -working-directory \ > > $WORKING_DIR -c $CLANG_SOURCE -target bpf \ > > -O2 -o -" > > > > In fact, util/llvm-utils.c has updated the default configuration as > > below: > > > > #define CLANG_BPF_CMD_DEFAULT_TEMPLATE \ > > "$CLANG_EXEC -D__KERNEL__ -D__NR_CPUS__=$NR_CPUS "\ > > "-DLINUX_VERSION_CODE=$LINUX_VERSION_CODE " \ > > "$CLANG_OPTIONS $PERF_BPF_INC_OPTIONS $KERNEL_INC_OPTIONS " \ > > "-Wno-unused-value -Wno-pointer-sign " \ > > "-working-directory $WORKING_DIR " \ > > "-c \"$CLANG_SOURCE\" -target bpf $CLANG_EMIT_LLVM -O2 -o - $LLVM_OPTIONS_PIPE" > > > > Maybe should update Documentation/perf-config.txt to tell users the > > real default value of clang-bpf-cmd-template? > > Sure, if you fell like doing this, please update and also please figure > out when the this changed and add a Fixes: that cset, Thanks for guidance. Have sent patch for this [1]. > Its great that you're going thru the docs and making sure the > differences are noted so that we update the docs, thanks a lot! You are welcome! Thanks, Leo Yan [1] https://lkml.org/lkml/2019/6/7/477
