Sure, please check them in v2. Thanks! On Fri, Feb 01, 2019 at 09:10:50AM +0100, Arnaldo Carvalho de Melo wrote: > Em Fri, Feb 01, 2019 at 03:06:41AM +0000, Changbin Du escreveu: > > Add document for how to pass bpf program with perf. > > That is a good start, see some comments below. > > > Signed-off-by: Changbin Du <[email protected]> > > --- > > tools/perf/Documentation/perf-record.txt | 13 +++++++++++++ > > 1 file changed, 13 insertions(+) > > > > diff --git a/tools/perf/Documentation/perf-record.txt > > b/tools/perf/Documentation/perf-record.txt > > index d232b13ea713..0925d987cad0 100644 > > --- a/tools/perf/Documentation/perf-record.txt > > +++ b/tools/perf/Documentation/perf-record.txt > > @@ -88,6 +88,19 @@ OPTIONS > > If you want to profile write accesses in [0x1000~1008), just set > > 'mem:0x1000/8:w'. > > > > + - a bpf source file or object file to select events by a bpf > > program. > > A source file (ending in .c) or a precompiled object file > (ending in .o) > selects one or more BPF events. > > > + The bpf program can attach to variant perf events based on > > section > The BPFa various > > + names. > > + > > + When passing '.c', perf searches installed LLVM to compile it > > into > a > > + object file first. Optional clang options can be pased by option > an > > + '--clang-opt'. > > + > > + perf record --clang-opt "-DLINUX_VERSION_CODE=0x50000" \ > > + -e ./tests/bpf-script-example.c > > + > > + Note: '--clang-opt' must place before '--event'. > > Please mention ~/.perfconfig, that needs a section in the > tools/perf/Documentation/perf-config.txt, for instance I have right now: > > [root@quaco ~]# cat ~/.perfconfig > [llvm] > dump-obj = true > clang-opt = -g > > The 'clang-opt' is the same as the command line arg you documented > above, dump object may be used to update a .o file, like: > > [root@quaco ~]# vim > /home/acme/git/perf/tools/perf/examples/bpf/augmented_raw_syscalls.c > > # Do some changes, save > > [root@quaco ~]# perf record -e > /home/acme/git/perf/tools/perf/examples/bpf/augmented_raw_syscalls.c sleep 1 > LLVM: dumping > /home/acme/git/perf/tools/perf/examples/bpf/augmented_raw_syscalls.o > [ perf record: Woken up 1 times to write data ] > [ perf record: Captured and wrote 0.023 MB perf.data ] > [root@quaco ~]# > > And if you are up to documenting the remaining features, which I'd > encourage you, please take a look at: > > tools/perf/util/llvm-utils.c > > In the perf_llvm_config function. there are more things that needs > documenting, and doing a: > > git blame tools/perf/util/llvm-utils.c > > Helps in getting the needed explanations, for instance, the original > patch adding the .perfconfig section was this: > > git show aa61fd05ca796 > > And it has, for instance, among others: > > # 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" > > Thanks for working on documenting these features! > > - Arnaldo > > > > + > > - a group of events surrounded by a pair of brace > > ("{event1,event2,...}"). > > Each event is separated by commas and the group should be quoted to > > prevent the shell interpretation. You also need to use --group on > > -- > > 2.17.1 > > -- > > - Arnaldo
-- Cheers, Changbin Du
