> On Mar 9, 2020, at 11:04 AM, Quentin Monnet <quentin@xxxxxxxxxxxxx> wrote: > > 2020-03-04 21:39 UTC+0000 ~ Song Liu <songliubraving@xxxxxx> >> >> >>> On Mar 4, 2020, at 1:29 PM, Jiri Olsa <jolsa@xxxxxxxxxx> wrote: >>> >>> On Wed, Mar 04, 2020 at 09:16:29PM +0000, Song Liu wrote: >>>> >>>> >>>>> On Mar 4, 2020, at 12:41 PM, Jiri Olsa <jolsa@xxxxxxxxxx> wrote: >>>>> >>>>> On Wed, Mar 04, 2020 at 08:08:07PM +0100, Jiri Olsa wrote: >>>>>> On Wed, Mar 04, 2020 at 10:07:06AM -0800, Song Liu wrote: >>>>>>> This set introduces bpftool prog profile command, which uses hardware >>>>>>> counters to profile BPF programs. >>>>>>> >>>>>>> This command attaches fentry/fexit programs to a target program. These two >>>>>>> programs read hardware counters before and after the target program and >>>>>>> calculate the difference. >>>>>>> >>>>>>> Changes v3 => v4: >>>>>>> 1. Simplify err handling in profile_open_perf_events() (Quentin); >>>>>>> 2. Remove redundant p_err() (Quentin); >>>>>>> 3. Replace tab with space in bash-completion; (Quentin); >>>>>>> 4. Fix typo _bpftool_get_map_names => _bpftool_get_prog_names (Quentin). >>>>>> >>>>>> hum, I'm getting: >>>>>> >>>>>> [jolsa@dell-r440-01 bpftool]$ pwd >>>>>> /home/jolsa/linux-perf/tools/bpf/bpftool >>>>>> [jolsa@dell-r440-01 bpftool]$ make >>>>>> ... >>>>>> make[1]: Leaving directory '/home/jolsa/linux-perf/tools/lib/bpf' >>>>>> LINK _bpftool >>>>>> make: *** No rule to make target 'skeleton/profiler.bpf.c', needed by 'skeleton/profiler.bpf.o'. Stop. >>>>> >>>>> ok, I had to apply your patches by hand, because 'git am' refused to >>>>> due to fuzz.. so some of you new files did not make it to my tree ;-) >>>>> >>>>> anyway I hit another error now: >>>>> >>>>> CC prog.o >>>>> In file included from prog.c:1553: >>>>> profiler.skel.h: In function ‘profiler_bpf__create_skeleton’: >>>>> profiler.skel.h:136:35: error: ‘struct profiler_bpf’ has no member named ‘rodata’ >>>>> 136 | s->maps[4].mmaped = (void **)&obj->rodata; >>>>> | ^~ >>>>> prog.c: In function ‘profile_read_values’: >>>>> prog.c:1650:29: error: ‘struct profiler_bpf’ has no member named ‘rodata’ >>>>> 1650 | __u32 m, cpu, num_cpu = obj->rodata->num_cpu; >>>>> >>>>> I'll try to figure it out.. might be error on my end >>>>> >>>>> do you have git repo with these changes? >>>> >>>> I pushed it to >>>> >>>> https://git.kernel.org/pub/scm/linux/kernel/git/song/linux.git/tree/?h=bpf-per-prog-stats >>> >>> still the same: >>> >>> [jolsa@dell-r440-01 bpftool]$ git show --oneline HEAD | head -1 >>> 7bbda5cca00a bpftool: fix typo in bash-completion >>> [jolsa@dell-r440-01 bpftool]$ make >>> make[1]: Entering directory '/home/jolsa/linux-perf/tools/lib/bpf' >>> make[1]: Leaving directory '/home/jolsa/linux-perf/tools/lib/bpf' >>> CC prog.o >>> In file included from prog.c:1553: >>> profiler.skel.h: In function ‘profiler_bpf__create_skeleton’: >>> profiler.skel.h:136:35: error: ‘struct profiler_bpf’ has no member named ‘rodata’ >>> 136 | s->maps[4].mmaped = (void **)&obj->rodata; >>> | ^~ >>> prog.c: In function ‘profile_read_values’: >>> prog.c:1650:29: error: ‘struct profiler_bpf’ has no member named ‘rodata’ >>> 1650 | __u32 m, cpu, num_cpu = obj->rodata->num_cpu; >>> | ^~ >>> prog.c: In function ‘profile_open_perf_events’: >>> prog.c:1810:19: error: ‘struct profiler_bpf’ has no member named ‘rodata’ >>> 1810 | sizeof(int), obj->rodata->num_cpu * obj->rodata->num_metric); >>> | ^~ >>> prog.c:1810:42: error: ‘struct profiler_bpf’ has no member named ‘rodata’ >>> 1810 | sizeof(int), obj->rodata->num_cpu * obj->rodata->num_metric); >>> | ^~ >>> prog.c:1825:26: error: ‘struct profiler_bpf’ has no member named ‘rodata’ >>> 1825 | for (cpu = 0; cpu < obj->rodata->num_cpu; cpu++) { >>> | ^~ >>> prog.c: In function ‘do_profile’: >>> prog.c:1904:13: error: ‘struct profiler_bpf’ has no member named ‘rodata’ >>> 1904 | profile_obj->rodata->num_cpu = num_cpu; >>> | ^~ >>> prog.c:1905:13: error: ‘struct profiler_bpf’ has no member named ‘rodata’ >>> 1905 | profile_obj->rodata->num_metric = num_metric; >>> | ^~ >>> make: *** [Makefile:129: prog.o] Error 1 >> >> I guess you need a newer version of clang that supports global data in BPF programs. >> >> Thanks, >> Song >> > > Thinking about this requirement again... Do you think it would be worth > adding (as a follow-up) a feature check on the availability of clang > with global data support to bpftool's Makefile? So that we could compile > out program profiling if clang is not present or does not support it. > Just like libbfd support is optional already. > > I'm asking mostly because a number of distributions now package bpftool, > and e.g. Ubuntu builds it from kernel source when creating its > linux-images and linux-tools-* packages. And I am pretty sure the build > environment does not have latest clang/LLVM, but it would be great to > remain able to build bpftool. Yeah, I think it is a good idea. Some more Makefile fun. ;) Thanks, Song
